Robert: Schleicher

THE

BIBLE

ROBERT SCHLEICHER

How to

build,

tune and drive

electric

and nitro-powered radio-control

cars

on and

off-road

Digitized by the Internet Archive in

2016

https://archive.org/details/isbn_9780760323984

South San Francisco Library

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SSF

S.S.F. Public Libfary

West Orange 840 West Orange Ave. South Son Francisco, CA 94080

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ROBERT SCHLEICHm

*

Voyageur Press

published in 2006 by Voyageur Press, an imprint of MBI Publishing Company, Galtier Plaza, Suite 200, 380 Jackson Street, St. Paul, MN 55101-3885 USA First

©

Copyright

discounts

bulk quantity for industrial or sales-promo-

in

tional use. For details write to Special Sales

MBI Publishing Company, Jackson Street,

St. Paul,

Manager at 380

Galtier Plaza, Suite 200,

MN

55101-3885 USA

2006 by Robert Schleicher Library of Congress Cataloging-in-Publication Data

With the exception of quoting brief passages for the purposes of review, no part of this publication may be reproduced without prior written permission from the Publisher.

All rights reserved.

Schleicher, Robert H.

The R/C car bible how to build, tune, and drive electric and nitro-powered radio-control cars on- and off- road / :

Robert Schleicher,

The information

book is true and complete to the of our knowledge. All best recommendations are made without any guarantee on the part of the author or Publisher,

who

in this

also disclaim any liability incurred

of this data or specific

tion with the use

in

connec-

details.

We

recognize, further, that some words, model names, and designations mentioned herein are the property of the trademark holder. We use them for identification pur-

poses only. This

is

not an

MBI Publishing Company

are also available at

Robert Schleicher has been writing best-selling hobby

ous

40 years. The author of several previincluding The Slot Car Bible, The Big

for nearly

MBI

titles,

How

Book of Lionel, and el

To Build and Fly Electric

Aircraft, Schleicher lives in

ISBN-10: 0-7603-2398-4 (pbk.)

Automobiles— Models— Radio TL237.S34196 2006 796.15'6-dc22

control.

I.

Title.

2006010777

Amy

Glaser

Designer: Kari Johnson

About the Author: books

cm.

1.

Editor:

official publication. titles

p.

ISBN-13; 978-0-7603-2398-4 (pbk.)

On the frontispiece: No one demands that you

actually race against others.

Most radio-control-car owners can for the sheer

thrill

of

race as quickly as they

it all.

Mod-

On

Niwot, Colorado.

the

title

pages:

Three 1/8 scale nitro-powered buggies dodge a spun-out car on the banking. at Rat Raceway.

Credits:

On

On

the cover:

Main image: There

are

two ways

to exit a tabletop: use

lift off and power down the slope. Rock crawling is the finesse side of radiocontrol competition, where precise balance and it

as a

Lower

launch pad or left:

control, rather than sheer speed, are

Lower middle: The performance

is

and correct any

step in

flaws. This

is

Mohr Raceway in

stand.

R/C

of 1/10 scale nitro Touring cars at

see

Touring cars are generally

the quickest class in on-road

is

racing. Here, a field

lined

Denver, Colorado.

up

The view from the 10-foot-high driver’s stand at RC Madness in Enfield, Connecticut, is magnificent and makes it as easy as possible for the drivers (up to 12 of them) to judge their cars’ movements

for the start

left:

within a fraction of an inch.

Upper

you can

Russ Horton’s 1/10 scale

on the tuning

right: 1/10 scale nitro

to win.

maximizing

to keep the car clean so

nitro Touring car

Lower

first

needed

the back cover:

Upper

right:

The

steering

on

this Associated

two-wheel-drive road-racing chassis

is

RCIOL

actuated direct-

from the wheel on the servo motor mounted across the front of the car. The two blue boxes are the radio ly

receiver (left)

Lower:

A

and the ESC

(right).

1/12 scale four- wheel-drive modified

buggy

scratching the air for sixth place overall at the 2005

ROAR

Off-Road Nationals.

CONTENTS CHAPTER

1:

Racing for Real

6

CHAPTER

2

Racing by Radio Control

16

CHAPTER

3:

Electric-Powered Race Cars

30

:

CHAPTER 4 Nitro-Powered Race Cars

46

CHAPTER

5:

60

CHAPTER

6: Electric

:

Chassis Perfection

Race Car Preparation

82

CHAPTER 7 More Electric Power and Speed

94

CHAPTER

108

:

Nitro Race Car Preparation

8:

More Nitro Power & Speed

CHAPTER

9:

CHAPTER

10: Driving

CHAPTER

1

CHAPTER

12: Paint

CHAPTER

13: Race Tracks for

CHAPTER

14: Clubs

CHAPTER

15: Sources of Supply

186

CHAPTER

16: Glossary

188

Index

1:

on the Dirt

Road Racing

118 130

146

Shop

156

R/C Cars

and Publications

168

184

190

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1

RACING FOR REAL

CHAPTER

race car with your mind. It's closer racing a radio control car than you might have guessed.

Imagine controlling a to

real

ONSIDER W’HAT YOU DO WHEN YOU DRIVE A FULL-SIZE AUTOMOBILE ON THE STREET.

How often

do you actually think that you need

the brake? Your

mmd

says stop

and the car

move your

to

scops;

you might remember actually having moved your

it’s

only by chinking back chat

foot. In essence,

with your mind, and your body reacts to those thoughts. control racing except you turn a

working a

lever,

much

foot from the gas to

the

It is

you

are driving

same with radio

smaller steering wheel with one

hand while

rather than pedal, to control the throttle using your opposite

hand. The brakes can be applied by the same finger that operates the throttle.

James

R. Barr, Steve

Goodreau of Horizon, and Andrew O’Bannon of HPI

Racing were especially helpful in preparing the material for this book.

RACING BY RADIO CONTROL

accelerate,

Driving a model car that

respond

is

controlled by

radio signals requires virtually the level

size

same

are

mind

When

on the

your

it

wall

degree you wish.

do so

at the

When

tiny steering w'heel with

throttle lever,

but you soon forget

that physical connection to the transmit-

says turn, the radio control car will

turn and

moving that

w'ill

pace you wish. Yes, you

your fingertips and pushing and pulling

of concentration as driving a fullrace car with a steering wheel and

pedal-to-throttle linkage.

the miniature machine

at the

ter that controls the car.

speed and

trol

your mind says

to

race car

is,

in

That radio conresponding

effect,

your very thoughts.

Opposite: There are hundreds of radio control race car tracks around the country, both paved and indoors and out. This is the RC Madness outdoor off-road track in Enfield, Connecticut.

7

dirt,

RADIO CONTROL OR REMOTE CONTROL?

are always just a bit too late to get the car to turn, go, or

some kind

stop as you wish. The radio control race cars you see on

of toy car that was controlled by a radio transmitter. There are also some toy cars that have a tether between be remote control, as opposed to radio control cars.

want it more turn, it will turn just a slight bit more. Similarly, you can control its speed within a fraction of a mile-an-hour. The

The

controls of a radio control race car are completely pre-

Most of us have had an opportunity

to try

these pages will respond only as you wish. If you to turn gently,

the car and the controller— you could consider those to true radio control cars send a radio signal

receiver translates

mands to move down the engine

from a

The com-

dictable.

up or slow

response

transmitter through the air to a receiver in the

car.

the signals into electronic

the steering or to speed

to

The more costly radio consame basic principles of radio

or motor.

trol race cars utilize the

do

The

it

HOW MUCH? The

through the air to a receiver do the toy cars. Having said that, try to forget any experience you have with a toy R/C car because it is a universe away from what it’s like to drive

slight bit

what you want it do it. This linear

exactly

when you want

it

difference between that toy radio control car

and

a

“serious” radio control race car can be expressed in dollars.

The toy

radio control car might

sell for as little

$20

complete with transmitter, while a serious radio control

a true radio control race car.

stumbles and bobbles,

race car will run at least

radio control car race tracks also have elevated driving stands (far

with boards or plastic strips

$200 with that much more for want

the transmitter. Expect to invest about $600 if you

careens and veers as you apply a series of corrections that

Above: Most

do

want a

exponential radio control.

in the cars as

jerks,

so. If you

usually referred to as fully proportional or

signals being transmitted

That toy car darts and

do

car will always

precisely is

will

to create the

8

left).

The paved surface

course configuration.

is

divided

Think of it this way; and experience You perfect racing and a model develop car and the to means to control it with your fingertips. Yes, you must control race cars and transmitters.

to be a regular racer with either electric or nitro power,

on- or otf-road.

It

are paying for

you want the quickest nitro-powered,

on-road car with transmitter, you won’t have change hack from S2,()0().

much

someone

else’s effort

learn to drive the car, but the mechanical elements are

WHICH TO BUY?

ready and waiting for you.

Money

veloped

is

nor really an accurate measure of the

differ-

ence between the vast range of radio control cars because part of what you are paying for is the decades of

skills to actually

talented drivers in

larly

them) identical

racing experience that have gone into the best radio

takes even

away) and find out

The

well-de-

(as-near-as-rules-can-make-

locate the nearest

that sells radio control race cars (even

cars.

more

cars.

would suggest you

1

It

win a race against other simi-

when they

hobby shop

200 miles and off-road

if it is

race on-

ROAR (Remotely Operated Auto

Racers) web-

most of the radio control car racing clubs in America by region. Attend the races and talk to the drivers and observe. There is no better source of information than the local racers. That information may not be accurate on a national level, but you will be racing with local folks. Often, one brand of car and transmitter may be popular in a particular area and another brand will be popular in a difsite

(www.roadracing.com)

ferent area. as

lists

There are a myriad choices of scale, as well

on and off-road types of cars. Often, only four or

of these different classes of cars given area. As a beginner, you the trend. all

Above: The radio

Buy

a “renegade”

will

would be

brand

Below: The nitro-powered road

the locals have to teach you.

racers, like

trigger for speed control.

Lee Schultz’

1/ 10 scale

touring class Acura, provide virtually

excitement and realism (and screaming sound) of real car racing.

9

w’ise to

follow

after you’ve learned

transmitters for race cars have a small steering wheel on the right side with a pistol grip

and

five

be popular in any

all

the

A REAL RACE CAR

however, a variety of racing classes for

The radio control

1/10, 1/8,

hobby are offered with either electric motors or internal combustion engines for power and in sizes ranging from 1/24 scale to 1/5 scale. The 1/24 scale cars are the smallest race cars designed for the

The

being just 1/24 the size of the

1/5 scale (and

some

the 1/12, 1/10,

and 1/8

The

1/8 scale cars are massive. If the real race car was 79

inches wide and 182 inches long, the 1/8 scale version

would be

9 7/8 inches wide and 22 3/4 inches long. of the lower-cost radio control race cars are 1/12 which would make our example car a more rea-

sonable 6 5/8 inches wide and 15 1/8 inches long. To determine the dimensions, simply divide the actual car’s

dimensions by the

scale; hence,

79

12

would is no

equal 6.5833 (close enough to 6 5/8 inch). There

standard scale for radio control race

Above: The

cars.

There

is,

off-road radio control race cars have long travel suspension as

Below:

If you

awkward

want

off-road.

ones

scale versions are available with

either electric or nitro power.

mensions. The 1/18 scale cars are usually referred to as

scale,

and

The 1/24 and 1/18 motors for power, and

Micros and the even-smaller 1/24 or 1/28 scale cars are usually in the Mini class. The other scales are referred

Many

/24, 1/18, 1/12,

1/6 scale) cars are the

scale cars usually have electric

real race car in all di-

to by their proportion: 1/12, 1/10, 1/8, 1/6, or 1/5.

1

1/5 scale cars in both on-

that will have fuel-burning engines.

that can qualify as potential racers with satisfying control,

and

and perfect balance so a landing

as this one seldom results in a tumbling crash.

to race off-road cars, there are several classes including, (left to right)

electric-powered four-wheel-drive buggies, two-wheel-drive buggies,

10

and two-wheel-drive

trucks.

ROAD RACING AND OFF-ROAD RACING

racing models available range from near-perfect replicas

You can buy a

of Formula

tually

ready-to-racc

any type of

model or

full-size race car.

a kir to recreate vir-

The

cars,

1

CART and

IRL

cars,

touring sedans,

to oval-racing Midgets. New Era Models even offers 1/10 and 1/8 scale nitro-powered slingshot and Funny Car

choices of road

drag

R/C

racers.

Off-road racing

is

extremely popular with

car fans so you’ll find examples of every kind of off-

road racer from a recreation of a buggy to a Baja pickup to a crusher truck to dirt-track sprint cars.

SOPHISTICATED RACING MACHINES Some of

the radio control cars have a simple gear

drive to the rear axle.

The more sophisticated (more

expensive) models will have a two- or three-speed

transmission similar to the automatics in real cars. better cars have front and rear suspension systems that are at least as complex as those in a real

The car

and

just

as

adjustable for spring rates, ride

height, roll stiffness, preload,

dampening, and

the other suspension-tuning tricks that can

one

real (or

model) race car quicker around

track than another.

Above: No one demands Most

that

you actually race against

others.

radio control car owners race as quickly as they can for the sheer thrill of it

Below: This modified two-wheel-drive

truck

resulting in this landing

was driven a on one

bit too slowly

soft front tire.

all.

over the jump,

all

make

a given

ELECTRIC

MOTOR POWER

The radio control

and a host of flyweight carbon

my

motors can be raced indoors or out. The electric motors are virtually silent except for a whine from the gears meshing (and the occasional crunching sound when you overcook a race cars with electric

You can often

is

fiber

components. In

view, the experience of racing electric-powered cars

a bit less realistic than the experience of racing nitro-

powered

cars because the

power source

is

not the same

type as used in a full-size real car. Because there

is

no

race the quiet electric-powered car

spilled fuel/oil mix, the electric-powered cars are less

m a vacant lot where the noise from a fuel-burning pow-

power the electric-powered you buy a spare battery pack you can recharge one pack while racing with the other. When the first pack’s charge is spent you can replace it with a freshly charged pack while recharging the first. The batteries do constitute a finite fuel load, so long

corner).

erplant might attract ejected

enough attention

to have

messy.

you

from the property.

somewhat The electric-

Generally, the electric-powered cars are less

expensive than the fuel-burning cars.

powered R/C

cars range

The

batteries that

cars are rechargeable. If

from $50 cars with rudimenta$500 race cars

won

or lost by the driver that

ry suspensions to highly-sophisticated

distance races are often

that have fully adjustable suspensions, differentials,

can best conserve battery power.

Above: The off-wad racing

courses are very similar to full-size motorcycle motocross tracks

with tabletop jumps, double and

triple

jumps, and series ofwhoop-dee-doos

12

like these.

FUEL-BURNING ENGINE POWER

These two-stroke engines use a special

fuel that

has

Real race cars are powered by internal combustion en-

lubricant mixed in that provides the lubrication for the

which makes a fuel-burning model car chat much W'hen you race a fuel-burning ra-

crankshaft and connecting rod bearings, as well as for

gines,

more

the piston

like the real thing.

dio control car

it

not only looks

like a real race car,

The fuel-burning powerplants

The

that are used in radio

those used in flying model aircraft.

and exhaust ports

in the walls

model ties his

cylinder.

^

*

Mohr Raceway

in

to race,

bring

tools, lights,

Aurora, Colorado. The car

is

not usually

car clean

or her

is

just

model

around the chassis

For the serious

racer,

one more element of realism that

to the real race car.

TOYOTA

and is

spares with you.

Most

tracks provide

workbench areas

a 1/10 scale electric-powered modified Taniyia Fornnda

13

after the

keeping the

J

TOYOT a

Above; Ijyou are going

fuel

can sometimes be spit-back through the carbu-

fuel has evaporated.

The two-stoke

of the

fuel

retor to create a film of oil

engine has no vah’es, just a piston that covers and uncovers intake

The

cars are often referred to as “nitro-powered” race cars.

control cars are usually two-strokes that are nearly identical to

walls.

ten includes nitro methane; hence, these fuel-burning

sounds like one. You also know that the power is coming from essentially the same source as chat of the real race car.

and cylinder

gasoline but a mixture of combustible chemicals that of-

it

like this 1

one at

Toyota.

REAL RACING

Hurdy-brand chassis set-up jigs for getting that last ounce of performance, just as you would with a fullsize race car. With the exception of actually sitting in the car (and the inherit risk that entails), you can do anything with a model R/C car that you can do with

any aspect of building, tuning, or racing a race car that you find fascinating, you can recre-

If there is

real

ate

it

with a radio control race

car. You’ll

find in-car

Spektrum- and Nomadio-brand telemetry, true rear wheel dynamometers from RC Dyno Systems, and the

Above: At

Is it

racing? Sure.

Is it real?

the larger races there’s a tech inspection where your car will be weighed, then dropped in a

special-size

Opposite:

a real car.

box

to

be sure

it

complies with the rules for niaxinunn width

I’he rock crawlers (both electric full-size

and

and

length.

nitro) recreate the seemingly impossible climbs oj the

machines as they clamber up and around

14

vertical rock walls.

Of course!

15

2 CHAPTER

RACING BY RADIO CONTROL When pull

you turn a hand-held steering wheel and a speed control trigger and a car that is a dozen feet away responds to your slightest whim, you are driving by radio control.

ADIO c:ONTROL

A SIMPLIFIED DESCRIPTION

IS

driver are transmitted to the still

how

has to learn

hand-held transmitter

to

HOW THE COMMANDS FROM THE

OF

model automobile. The

move

the steering wheel

will that relay his or her

driver (that

and

would be you)

throttle trigger

on the

commands.

RADIO CONTROL TRANSMITTERS

Graupner, Megatech, Hitec, Tower, and

would recommend that you purchase the best transmitter you can afford so you can keep it for all the future models you may want drive. The toy transmit-

others.

I

casual

sell

transmitters are de-

and

for less

so

racers,

the

to be used by

transmitters

included with cars as package deals are

provide control in a very lim-

ters often

AM

The

signed to

often

AM. FM

offers

more choices of

of steps. The higher-priced transmitters have exponential control,

channels, better response, and precise

which means there

to pay

ited series

is

cernable step in the

steering Airtronics

or

the

virtually

no

movement of

throttle

and Futaba

are

adjustability of

dis-

the controls. Expect

transmitter for a serious race

the

car.

You

brake.

can probably get the best advice on

two of the

which transmitter to buy by talking to the folks in your local race track, but you would be wise to do some research on your own to decide which transmitter would best meet your specific needs now and in the foreseeable future.

or

top-of-the-line brands but others have

similar features. Professional drivers of

radio control race cars have used just about every brand including Futaba, Airtronics, Polk’s, JR, KO, Academy,

Opposite: This four-wheel-drive modifted-class buggy

and ready

all

between $150 and $400 for a

to dig its

way along

to

17

is

maintain that

under perfect control fly itig

pace.

Above; Most

tracks,

even those

set tip

temporarily in a parking

lot like this

Hohbytown USA

Fall Classic race in

Colorado, provide an elevated platform so the drivers have a better view of the cars.

18

Arvada,

The

For most radio control driving you will only need two channels: one for the steering and the second for throttle. The throttle control trigger on the transmitter should have a second trigger to allow you to apply the brakes by releasing trigger pressure and flicking your trigger finger outward. It’s worth the cost to buy a radio with a third channel in case you want to power a reverse or turn on the nitrous-injector (see Chapter 9) for a burst ot double horsepower.

top-of-the-line transmitters include

justment features that can make dio control car.

The

have a dual rate or

steering

it

and

some

ad-

far easier to drive a ra-

throttle controls

D/R adjustment

that allows

may

you to

program how quickly the car will respond your steering and speed control inputs. The transmitter may also have endpoint adjust and adjustable travel for the steering wheel control that can be car’s

set to

determine

wheels will actually turn, right or

also be trim adjust switches so

left.

you can

how

far the

There should

set the neutral

position for the steering (straight ahead) and for the throttle (idle) with additional adjustments for throttle

response and brake timing and response.

COMPUTERIZED TRANSMITTERS The more expensive radio transmitters, like the Futaba 6EXA, Polk’s Tracker III, Flitec Optic 6,JRXP9303, and others have built-in programs that allow you to program in a variety of special control settings and adjustments. You can program the transmitter to save both exact adjustments of the controls and specific combinations of controls. This can be especially helpful if you race both electric and nitro cars on- and off-road.

Above: The preferred position for holding left)

the trans?nitter

is

to

have

it

at about heart level with your

dominant hand's

(right or

index finger on the speed trigger and the opposite hand working the steering wheel control. The grip on

the transmitter usually has the option of swinging right or

Below: The view from

the W-foot-high drivers’ stand at

easy as possible for the drivers

(

up

to

allow easier use by either the right or

left to

RC Madness

in Enfield, Connecticut,

12 of them) tojtidge their

19

car’s

is

movements within a

left

hand.

magnificent and makes fraction of an inch.

it

as

FCC LEGAL “ C Car Frequencies Channel

No.

Frequency No.

Channel No.

Frequency No.

Channel

m i i • 1

2

3

4

26 995

27 045

27 0 95

27 145

^

64

^

68

430

75 470

75 510

75 550

75 590

74

76

78

80

82

84

75 710

75 750

75 790

75 830

75 870

88

90

75 950

75 990

75

No.

Frequency No.

I

27

1

95

27 255

70

72

ill!

III III

75 670

1

86

Channel No.

5

75

630

1 Frequency

The

larger transmitters have

No.

75 910

enough memory

for

up

numbered clothespins, to match each of the 36 frequenAny missing clothespin is the indication that the

to

30 different race car memories.

cies.

missing frequency

RADIO CONTROL FREQUENCIES The

radio control signals are carried

When you on

and

specific fre-

quencies so that the radio receiver in your car— and only

and 30

m

modelers

the 75

in the

MHz

frequencies: 6 in the 27

tenna to make

it

you grab the clothespin from it

your transmitter’s an-

easier for the official to find

and your frequency

if

has a frequency board, usually with 36 color-coded and

you

are

through driving.

It

also effectively prevents

thousands of radio transnutters and receivers that use the older range of 21 frequencies,

but these cannot be used

if even

Most

one of the new 20

tracks post a

list

your car

necessary and to help you

rememwhen

ber to return the clothespin to the frequency board

United States. Each model race car track

still

are prepared to drive,

transmitter and receiver and clip

MHz

primary band to car and boat

Above: There are

m use by another driver.

the frequency board that matches the frequency of your

the receiver in your car— will respond to those signals.

The FAA has assigned 36

is

enter the driving stand area of the track

MHz radios arc being used in

the area because of interference.

of the available frequencies and their color codes.

20

anyone

\y 'i\<;

Above; There are This

is

several systems to prevent

more than one

racer from using a radio frequency.

a system of spring clips with 39 frequencies on the frequency board at

\'ote that four of the frequency clips are missing,

Below: The frequency hoard

at the

with the radio frequency attached

to

Mohr Raceway

in

Aurora, Colorado.

which indicates that those four are being used

RC Madness

to

drive cars.

Track in Enfield, Connecticut, uses clothespins

prevent more than one frequency from being used at a time.

21

The lower-priced radio control transmitters have a you buy is what you get. The

from using the same frequency. Your responsibility and return the clip to the frequency board as soon as you are through driving. If you have a radio with another frequency, you must select the clothespin to match that frequency alone and return it when you are through. Some of the more soelse is

fixed frequency— what

to use only that frequency

medium-priced transmitters have a removable chip so you can buy an optional frequency and a matching receiver. Although 36 frequencies are available, usually only 12 or so are usable because transmitters are often supplied with a relatively few popular frequencies. You

phisticated transmitters have adjustable frequencies so

you have a

same

might ask your dealer to be sure your transmitter is not one of dozen he has sold with the same frequency, and if so, ask him to order a transmitter or another

apply— select only the frequency to match the clothespin you have selected from the frequency board. choice. Again, the

Above: that

rules

Coiiventioiuil transmitters

must be matched

and Spektrum

to the car.

(top) are

and

receivers use a small replaceable crystal

The newest 2.4

programmed

to

respond only

22

pack (bottom)

MHz crystal packs from Novam to

your

transtfiitter

and

(center)

receiver.

crystal with

another frequency.

It is

possible to change

crystals in either the transmitter or the receiver at

an

additional charge.

AUTOMATIC FREQUENCY SELECTION One

ol the major breakthroughs for radio control car

racing has been the production of the digital spectrum

modulation (DSM) system. The DSM system scans the GHz band looking for an open channel. W’hen an un-

2.4

used channel

is

found, the system locks on that channel

and transmits. Up ate

DSM

to 79 users can simultaneously oper-

systems. This

is

purely digital radio frequency

(RF) link between the transmitter and the receiver that

is

based on direct sequencing spread spectrum (DSSS) technology.

It

operates within the ultra-high 2.4

GHz

worldwide ISM band, provides unequalled signal resolution, and is immune to the most common forms of RF

Above: The

2.4

MHz modules snap into the crystal cavity on

The Spektrum unit has

Chadd Brockman wraps (works a

Below: The

its

own

built-in aerial so

most of the higher-priced radio control car

you can remove the stock transmitter

the handle of his transmitter with the

bit like Velcro) to

transmitters.

aerial.

new self-adhesive gauze bandages

provide a more comfortable and slip-free grip even with sweaty palms.

signals from the radio transmitter are fed to the in-car receiver like this two-channel unit from Airtronics.

23

interference. It requires no crystals and completely frees you from ever having to monitor frequency usage again. With the Nomadio and Spektrum DSM Systems you can literally plug this phenomenal technology into existing transmitters like the KO Propo EX- 10 Helios, Nomadio, and Spektrum DSM. The DSM systems are becoming available from most

is

some

Above: The motor speed

car,

in electrie

R/C cars

is

bit

too

fast.

but

Usually you

signals are picked up by the receiver in the which translates the signals into steering and

speed commands. The speed

powered

cars are received

trol (ESC),

No modification

commands

in electric-

by an electronic-speed con-

which transmits them

electrically to the

motor. In a nitro car the signals are relayed to a servo

controlled by

that sends electronic signals directly to the

is

drivers

The radio

Hitec, or Airtronics three-channel, receivers.

drivers find the system

Most

in response,

THE RADIO CONTROL SYSTEM IN THE CAR

Spektrum, Nomadio, and Polk’s have DSM modules available but more are coming. The modules simply replace the existing crystals in the transmitter and receiver

KO, Futaba,

receiver.

no noticeable change

can use the fine-tuning switches on the transmitter to ad-

ly,

module-based transmitters and

is

just the response to a comfortable range.

of the radio control transmitter manufacturers. Current-

in JR,

needed to either transmitter or

find that there

an in-car

motor

24

digital speed control (electronic speed control)

like these

Associated

I

RP-scries units.

motor, which partially rotates a crank to open or close

The and nitro-powered cars are transmitted to servo motors, which actuate the steering arms through a linkage. The brake is actuated by moving your throttle control finger forward (rela.\ing the grip) to push on the brake trigger. the throttle butterfly through a series of links.

steering

commands

in

both

electric

HOW MUCH? It

the car

is

not supplied with a receiver, steering

serv^o

motor, and throttle servo motor (or an electronic speed control [ESC] for electric-powered

cars),

you can

expect to pay between $150 and $500 for these three

Above: (the rod with

The speed control After the servo

By

A

single servo

two brass

trigger is

is

used

collars) while a

operate the butterfly or slide valve on the carburetor

on the transmitter operates the servo

in a

reversed (by letting off on the throttle lever)

reversing the servo from the idle position, the

Below: The

to

second rod (running beneath throttle-control rod) operates the brake.

servo motor on the

left

arm

it

forward direction

that actuates the brake

is

put

open the to zero

throttle.

or

idle.

into action to gradually apply the brake.

operates the carburetor on this Kyosho nitro 1/ 10 scale touring car,

with a second lower rod activating the brake. The servo on the right has a single to the steering

to

automatically returns

mechanism

at the front of the car to steer the car.

25

arm

that leads

26

components that the R/C gear.

The nitro-powered cars require a separate battery pack to provide power for the car’s on-board servo motors. If you are driving a nitro-powered car, it’s

car catalogs refer to as radio

For electric-powered cars you

will also

need to

spend another $50 to $250 for two sets of batteries and $50 to $250 for a battery charger.

wise to buy a battery charger for the receiver batteries

and

FAIL-SAFE

CONTROL

The electric-powered cars draw the current to operate the servo motor from same battery pack that powers the car’s

motor.

Many of the ESC

out (EEC) circuit that

and

leave

will

enough current

pack while you

You should

you can

install a fresh set

stop power flow to the motor to operate the throttle

Opposite: The servo motor on through a bellcrank

( top,

right)

Above: The

this

second

set

of batteries for the

and nitro-powered

and

teries into the transmitter before every race it

will

on

this

The brake

Associated

with

is

RClOL

actuated by a second rod from the servo (lower

two-wheel-drive road-racing chassis

actuated directly from the wheel on the servo motor mounted across the front of the

The two blue boxes are the radio

receiver (left)

27

and

the

ESC

(right).

and put the

be ready for the next

Traxxas I/IO scale four-wheel -drive stadium truck operates the carburetor rod.

cars,

a battery charger. Again, put a freshly charged set of bat-

spare set in the charger so

and a second

steering

race.

also have a

transmitter, for both electric

units have a battery cut-

steering to get the car back to drivers’ stand.

is

a spare battery pack so

of batteries before every race and charge the second

car.

left).

race.

ADJUSTING BRAKE ACTION It

takes

some

control the extension of your index finger since most of

our motor

practice to learn to use just your index

finger to control both throttle

you must learn

is

to

and brake. The response

know when

the trigger

is

skills require

Chadd Brockman modified

neutral position without the need to look at your fin-

ulate the speed.

From that neutral position, forward, or outward movement of the trigger finger applies the brake— the

trigger

harder and farther you extend your index finger, the

whenever he completely

is

applied.

Above: The

It

takes

some

With practice you

can modulate the brakes as effectively as you can mod-

in the

ger.

more brake

the compression of our fingers

to pick up, hold, or control levers.

on

his transmitter so

it

the brake

rests a bit closer to his

index finger. The position provides instant braking lets

off the throttle.

practice to learn to

servo motor for the steering

oti this

Associnted

between the upper and lower chassis plate

to

1

0TC4

four-wheel-drive 1/U) scale touring car chassis

is

sandwiched

provide a rigid mounting for more positive steering response.

28

Above: The

top-of-the-line radio control car transmitters have a dual-action throttle trigger with a

second adjustable trigger on the forward side that can be used

29

to

apply any desired

amount of braking.

3

ELECTRIC-POWERED

CHAPTER

RACE CARS Class are

for class, the

electric-powered cars

slower than nitro cars because the electrics are forced to carry the extra weight of batteries. just

a

bit

HE ADVANTAGE

IS

SLIGHT COMPARED WITH THE ADVANTAGE OF QUIET AND CLEAN

power. You can race an electric-powered car in

many

indoors, where the noise and smell of a nitro-powered car pletely unsuitable

(if

not

illegal).

Team

Associated,

including

places,

would make

Team

com-

it

Losi, Traxxas,

Tamiya, Kyosho, and HPI are the major suppliers of ready-to-race

electric-

pow'ered radio control cars for both off-road and pavement racing, but there are literally

Corrally,

hundreds of others including firms

OFNA,

like

Xray, DuraTrax, Power Racing,

Mugen, Schumacher,

MRC,

Yokomo,

Proline,

RDLogics, and others.

CHOICES, CHOICES, CHOICES

oval

The choice of race-ready

at

electric-powered

pan

cars with a sidewinder

motor

the rear, to the incredibly complex

radio control cars range from the simple

four-wheel-drive 1/8 scale monster trucks

1/24 scale cars like Kyosho’s Mini-Z

with centrifugal clutches, two-speed or

machines that you can race

in

your garage,

three-speed

and

transmissions,

to 1/18 scale two-wheel-drive hard-bodied

brakes,

“play” cars, to the 1/12 scale Lexan-bodied

systems front and

Opposite; There’s nothing

to top the

fully adjustable

reverse,

suspension

rear.

racing action of off-road 1/10 scale machines like this

four-wheel-drive truck at the 2005

31

ROAR

Off-Road Nationals.

DOING

DIRT

WITH ELECTRICS

book. Most of these national and

There are dozens of 1/10 scale two-wheel-drive off-road buggies that you can choose from for that first electric car.

You

are likely going to trash the first one, so

scale cars, like this

real racers are legal for

international races,

of tuning and hop-up equipment

list is

both

ROAR

and the choice

nearly infinite.

The next step up m performance is a four-wheeldrive buggy. The 1/10 scale racing buggies will have plenty of power, and that drive at all four corners results in far more control, more traction, and quicker lap times. The four-wheel-drive cars are also more complex, so be prepared to spend more time with maintenance and tuning.

some-

thing from K-Mart might be good enough, but consider one of the 1/18 scale buggies like the Losi Mini-T or the Associated RC18B to get a better idea of what a serious off-road racing car might offer. When you buy your first real off-road race car, choose one of the brands in this

Above: The I/IH

IFMAR

compact RC18B from Team Associated,

are the smallest hobby-type off-road racers.

32

The

tour-wheel-drive trucks and stadium trucks are

similar to the 1/1 scale rock crawlers,

more

and a number of compete

successful 1/10 scale competitors also

a tun class in off-road racing because the vehicles look so

the

ungainly. However, the competition

with 1/1 scale rock crawler trucks. The ultimate rock

any other racing

One of the most tioned racing

This

is

is

is

just as fierce as in

have steering both front and rear like the from the crawlerstore.com chassis with Tamiya Clodbuster drive units connected to steer on both front and rear. The four-wheel-steering cars have a third radio channel to allow the speeds of the front and rear axles to be adjusted independently, depending on which end needs the most grip. These cars compete in the Super Crawler class. These Super Crawler class rock craw'lers may have up to 10 ounces of lead shot in each front tire. The four-wheel-drive, two-w'heel-steering cars can run 5 ounces in the front tires. The extra weight helps keep the front end down on vertical climbs, and the tires alone are almost heavy enough to be a vehicle of their own to scratch and grab each bit of traction to clamber up the rocks. craw'ler trucks

class.

fascinating classes for

NN

ROAR-sanc-

the 1/10 scale electric dirt oval class.

radio control equivalent of Saturday sprint races

at the local dirt oval

with relatively simple 1/10 scale

two-wheel-drive cars.

MONSTER TRUCKS The monster truck category includes machines that are more or less replicas of the crusher trucks, but the models are

cle

fun

designed to be raced, as well as used for one-vehifests.

The smallest are the

6 1/2-inch long

Kyosho

Mini-Z trucks that are close to 1/24 scale. The largest are machines like Tamiya’s TX2 Clod Buster and Traxxas

E-Maxx that

are near 1/8 scale.

ROCK CRAWLERS

chassis

ROAD RACERS

The most spectacular monster trucks

climb a wall the size of a concrete block or inch their way

you are driving just for the fun of it, you might prefer one of the more-detailed cars with an injection-molded plastic body and the detail of a diecast car like the 1/10

up a

scale

are those used for

rock crawling competition. These machines can near-vertical rock face. Their

If

literally

performance

Above: The Kyosho Mini-Z sports ami

is

very

GT cars,

like this

33

Tamiya

XB-series,

HPI Dash

Lamborghini Countach, are about 1/24

series,

scale.

or the

MRC

Great Power

cars.

1/10 scale cars are also raced indoors on paved tracks. There are a few indoor radio control tracks where the surface is indoor-outdoor carpet. These tracks provide a

There’s a racing series for the Mini-Z car but you’ll have

consistent surface without the changes in texture and

series;

1/14 scale cars like the Carisma

1/18 scale ready-to-race cars like the HPI Micro ries;

or the Kyosho Mini-Z series of small 1/24 scale

to arrange your

own

races for

The most popular

class

1/10 scale touring cars like

HPl-Racing’s Pro

4,

Team

most of the other

se-

unevenness that can happen on paved track, especially a paved track temporarily set up in a parking lot. Some

cars.

of on-road racing are the

Team

clubs and groups have portable tracks or rent space in

Associated’s TC4,

Losi’s JRX-S,

415 MS, Schumacher’s Mi2, Yokomo’s

Tamiya’s

TRF

empty warehouses

for race dates.

MR4TC, Xra/s

TIFK, and Corally’s RDC. If you are considering racing and want an el

series;

RS4

entry-lev-

car at the lowest possible price, consider the 1/12

scale

on-road and oval

sold as

cars, often called

on-road pan

RC 12-series. The RC12 cars are kits and you must supply your own motor, body,

cars, like the

Associated

radio gear, and batteries, but they

make

a great first step

up from ready-to-run cars. There are ROAR national championship and IFMAR international championships for these

The 1/10

cars.

scale cars race

on pavement, usually blackThe

top, but there are a few concrete-surfaced tracks.

Above: The

MRC Great Power series of 1/12 scale GT cars,

Porsche Carrera

GT super car,

are sold with transmitter

Below: The Kyosho Mini-Z series of cars

like this replica

and other

of the

radio gear.

includes replicas of most of the most famous

exotic super cars like this 1/24 scale

34

2005 Ford GT.

Above;

Tfte

MRC Super Power cars include the transmitter with a choice of four channels,

UOOmAh Below: The smaller The

rechargeable

entry-level

series includes these replicas

NiCad

batteries,

and forward and

1/W scale MRC Super Power series

of the LeMans-winning Porsche 91

35

1

reverse speed control.

does not have proportional steering.

GT-1/98 and

the

LeMans McLaren FI GTR.

For Off-Road Racing Classes for Electric-Powered Cars

and

Trucks:

1/10

scale Electric

1/10

scale Electric Truck

1/10 Scale

For

buggy (IFMAR

Electric Dirt

Classes)

Oval

On-Road Racing Classes

for Electric-Powered Cars:

1/12 Scale

Electric

(IFMAR

1/10 Scale

Electric

(Can-Am/GTP/WSC GT/GT-1 /Trans- Am)

1/10 Scale

Electric T-2 touring

1/10 Scale

Electric

CART/IRL/Formula

1/12 Scale

Electric

Oval

1/10 Scale

Electric

Oval

Class):

Car (IFMAR ISTC

RACING AN ELECTRIC-POWERED CAR OR TRUCK If there’s a

chance you might want to try your

a

Class)

1

number of national championships

listed below.

ROAR

popular electric-powered radio control cars and trucks

skill at

and driving against others, pick a car that is capable of matching the ROAR specifications. The ROAR rules are on its website. Classes that indicate IFMAR (International Federation of Model Car Racing) are run under international rules so a car

vehicles. In essence, a truggy

that meets these specifications can also be run interna-

1000-style pickup truck.

race car setup, tuning,

tional races. In addition to local races,

in all the classes

has racing classes for the most

in these classes:

Some the

tracks offer additional classes or subdivide

ROAR classes. One of the newest is for super-modified

monster trucks with pickup bodies

ROAR sanctions

36

is

called truggy-class

a recreation of a Baja

DRIFTING two meanings: The current popcompete in style contests with the tail of car sliding around in a prescribed pattern. The sport of drifting was born in Japan, but it is now popular around the world. There are several radio control cars from HPI-Racing, Yokomo, and others that

The term ular use

“drifting” has

is

to describe cars that

are specifically designed for drifting. cial chassis for drift cars

that

move

They also offer spemotor or engine

the

forward to make rear-wheel spin easier to control. Several

more

firms offer drifting tires that slide

easily

than

conventional racing rubber.

The more with

tail

meaning of drifting is to around a turn, usually hung out far more than the front.

traditional

describe a car that

of the car

is

sliding

Off-road cars are drifting through virtually every corner.

You can adjust

trol race cars to

on the

the chassis

induce more or

better radio con-

less drift, either at the

front or the rear of the chassis.

Opposite: The Kyosho Mini-Z a spring

mount

chassis has a sidewinder-style

motor mount parallel

rear suspension for the motor/axle unit

Above: The front and

and independent

rear suspension geometry, shock absorber,

on the 1/18

Below: Team Associated

offers

scale

Team

and

to the rear

axle with

front suspension.

chassis are fully adjustable

Associated four-wheel-drive RC18B.

a race-ready

RC18T Factory Team

four-wheel-drive off-road truck.

37

Kit high-performance 1/18 scale

Above; Reggie

Sauicieii

ami Neal

Sartor’s I/IO scale

Modified

2WD truck

Below: Reggie and Neal campaign a team of off-road this

1/10 scale Modified

38

is

a Losi model with an

cars that includes

4WD Losi racer.

MS2

motor.

TEAM

LOSI

Adjustable

Battery

upper suspension

tray

HOP-UP PARTS

Adjustable upper suspension link

link

Above: Reggie Scadden ami Neal Sartor have added 1/10 scale

Team

Losi

XXX-4

all

the available

Team

Buggy, including a bright red anodized

39

Losi

hop-up parts

aluminum heat

to this

four-wheel-drive

sink over the motor.

i

Above: The Kyosho Mini-Z Monster but

it

offers

is

only about 6 1/2 inches long (close to 1/32 scale),

four-wheel-drive

and

40

front

and

rear suspension.

Above; The Kyosho Monster

is

offered with n rouge of monster truck bodies.

41

Above; The Tamiya TX2 Clod Buster four-wheel-drive The

Opposite Above: This 1/W

chassis

front axles are the

most

common

for the rock crawler cars.

CNC-milled shock mounts with all-new shocks, motor, and radio equipment.

This 1/ 12 scale car has a Bender is

from Thimdertech Racing and has

scale car has a

Bender CNC-milled

cantilever suspension.

chassis with

Tamiya TLC-l front and rear steering

for the 2.2-class (2 1/2-inch tire Ol), 12 1/2-inch wheelbase, 12 1/2-inch overall width)

rock crawler competition in the Super class.

Opposite Below: This

rock crawler truck has steering both front

from the crawlerstore.com and Tamiya Clodbuster drive

42

and

rear with

units connected to steer

an

NN chassis

on both front and

rear.

axles

43

Above: This Factory Team RC3 from Team Associated four-wheel-drive I/IO

scale electric touring car kit

includes the majority of the special lightweight racing components.

44

Above; Mike and Sam Urban, a father and son Formula 1 team, race these 1/10 scale Tamiya electric-powered McLaren Formula 1 cars that have been updated from 2003 to 2004 cars with

new paint and

the

new ears

45

that identify the later cars.

4 CHAPTER

NITRO-POWERED RACE CARS The most exciting vehicles

radio control ore,

in

without doubt, the fuel-burning race cars, both on-road and

the dirt.

in

ACERS REFER TO THESE CARS SIMPLY AS NITRO MACHINES BECAUSE NITRO METHANE

one of the components of their exotic

though

a few of the giant 1/5

and 1/6

gines, but they require a gasoline/oil

fuel.

Most do not burn

scale cars

m ixture.

gasoline,

IS

al-

do run lawnmower-style en-

The

fuel for the nitro

machines

also includes the necessary lubricating oil for the engine.

TWO-STROKE POWER

that connects the piston to the crank-

The two-stroke engine has proven to be the most powerful mass-produced en-

shaft.

A

four-stroke engine has

all

that

plus at least one camshaft, typically

gine design. Motocross motorcycles, for

four valves for each cylinder, four of

example, allow four-stroke engines with

some

250 cc (cubic centimeters) displacement to race with 125 cc machines because the 125s deliver about twice the power. Similarly, the 500 cc four-stroke engines run with 250 cc two-strokes in motocross.

least four valve springs. Virtually all ra-

A

and

at

dio control cars use two-stroke engines,

although there are some four-stroke engines that are used craft that

The two-stroke engine has just three moving parts: the rotating crankshaft, the piston that goes up and down inside the cylinder, and the connecting rod

Opposite:

type of camshaft-followers,

m

flying

model

air-

could be adapted to the 1/5

scale radio control cars.

The

fuel

carburetor

crankcase

is

and

air

mixture from the

pulled into the engine’s

when

the

piston

moves

1/8 scale nitro-powered buggy wheelies off the banked south turn at Rat Raceway.

47

upward to create a vacuum in the crankcase. There are a number of holes or ports in the cylinder walls and one port is connected from the air intake and carburetor to

the piston

the piston

rises, it

the cylinder by the burning

tu'o-stroke engines are such suc-

cessful power-developers

On

compresses

is what happens to the exhaust. a four-stroke engine, the exhaust merely blows out

through the pipe and muffler (unless

and the spark plug is fired to ignite the charge. In a radio control model car engine the spark glows all the time (called a glow plug) and the that charge

turbocharger, but those are not used

it is

used to drive a

on model

race car en-

The exhaust from the two-stroke engine enters a massive, bulged metal chamber that is called an expansion chamber. The shape of that chamber has been developed to help force the fuel/air mixture to exit more slowly than gines).

fuel/air charge is ignited by a combination of the pressure from the compression and the glowing plug. When

Above: Three

down

The primary reason

into the cylinder barrel to allow the charge of fuel and air reach the area between the piston crown and the com-

When

forced

uncovers another port that is called the exhaust port because that’s how the spent fuel/air charge leaves the engine.

feed the fuel/air mixture into the crankcase. Another set of ports, called transfer ports, runs in two channels cast

bustion chamber.

is

fuel-air charge, the piston

I/H scale nitro-powered buggies dodge a spiin-oul car on die banking at

48

Rat Raceway.

it

would normally and that extra time allows more pow’er Irom the burning fuel/air mixture. The shape of the expansion chamber must be modified when some form of noise-reduction is used. Consequently, none of the quiet expansion chambers produce quite the power of the noisy ones. The ready-to-race,

before you attempt to enter an organized race with a car

to be extracted

that

nitro-powered radio control cars usually have expansion

termined by multiplying the area of the cylinder bore times the stroke (how far the piston travels through

fitted

with such a chamber. that power radio control cars are rela-

tively small, typically

between 0.12 cc and 0.29 cc

dis-

placement. That’s about 1/lOOth the size of a typical motocross motorcycle engine. The displacement is de-

chambers with some lorm of muffler. The racing regulations for radio control cars are very specific about what brands and sizes of expansion chamber are legal for organized racing. The chamber on your ready-to-race car is probably legal for racing anywhere, but it would be a good idea to check with your dealer or the car’s manufacturer to be sure. If you are replacing the expansion chamber with an aftermarket item, find out if it is legal

Above: A comer marshal

is

The engines

the barrel). That

means the piston

is

about the

size

of

a finger (or toe, in the case of the 0.29 engines). Given the light weight and minimal wind resistance of the

model

car, these

engines produce enough power to

and buggy can top

rocket a 1/8 scale nitro road racer to over 70 miles

hour. Even a dirt-racing 1/8 scale nitro

40 miles an hour.

reaches for a stalled 1/10 scale nitro-powered stadium truck at Rat Raceway.

49

THE

DOWNSIDE OF NITRO

SIZE

when

DOES COUNT

fled engines emit a wailing

There are a few 1/5 scale electric radio control cars running around but the combination of massive batteries to power equally massive motors is not practical.

enough

With

Nitro engines can be extremely noisy, especially fitted

with a racing expansion chamber. Even the muf-

sound that is unpleasant prompt your neighbors to enlist some police persuasion for you to cease driving the car. When you are driving a nitro-powered radio control car, it would be wise to find a dedicated race track or some distant to

paved parking

lot or

vacant

If size

Do

trol cars to

size limit.

be the 1/8 scale cars. Yes, the 1/5 and 1/6 both on-

dirt, have been developed enough so and most sophisticated machines are the 1/8 scale racers. The 1/8 scale nitro touring cars have 0.29 engines and are the fastest things on pavement, as are the 1/8 scale nitro buggy-class cars on the dirt.

the fastest

There’s an international racing class for 1/5 scale on-

road cars with 23 cc displacement engines, but they are

mtro-powered car indoors. There are some indoor cracks but they have massive exhaust fans to evacuate the noxious fumes.

run primarily

a

scale nitro-powered

no

road and in the

field.

not even consider running or racing

Above: This l/IO

is

matters to you, consider the ultimate radio con-

scale cars are larger but the racing classes,

The fumes that are exhausted from these machines are obviously poisonous— inhale enough of them and you’ll die or enough cells will die that will noticeably affect you. You probably don’t make a habit of inhaling the exhaust from your daily driver automobile or motorcycle either.

a nitro-powered car, there really

Dodge

Stratos

is

cars are even bit smaller

drifting (powersliding)

50

in

Europe and

more

than a

Asia.

like real cars

The

larger 1/6 scale

because they are only a

full-size go-kart.

around a broad curve at Mohr Raceway.

RDLOGIC'S 1 /8 SCALE FOUR-WHEEL-DRI VE SHO BUGGY Receiver

Throttle

servo motor

Engine Steering

servo motor

Pull starter

Exhaust Tie rod

expansion

Stud-style tires

Fuel tank

Above: RULogics massive 1/8

scale four-wheel-drive

disc brakes,

Carburetor

chamber

SHO buggy has a

and a machined aluminum

51

0.21 Infiniti competition engine,

chassis.

'

The massive

1/5

and

1/6 scale cars are over 2 feet

long and can top 35 miles an hour off-road. The readybuilt Traxxas 1/6 scale monster buggy with 23 cc Zenoah engine or the 1/5 scale HPI Baja 5B buggy are two-wheel-drive.

The

1/8 scale nitro-powered monster trucks like

Traxxas T-Maxx, S-Maxx, and Sportmaxx are some of the most popular off-road vehicles. These giant trucks

have 2.5 cc engines with portable (removable) push-button electric

starters.

NITRO OFF-ROAD RACE CARS The most popular trucks, buggies,

nitro cars by far are the 1/8 scale

and

truggies.

chines out in the desert or the ly

good

taste

1000 in a classes

Above: The I/IO

scale nitro-powered

Below: Nitro-powered I/IO

of what

real

it

would be

and

you’ll get a tru-

like to race the

Baja

buggy. There are international racing

and events

for

all

of these cars sponsored by

stadium trucks are one of the more popular off-road racing

scale off-road buggies are usually the cpdckest cars in the dirt.

52

Get one of these ma-

hills

classes.

For Off-Road Racing with Nitro-Powered Cars

and

Trucks:

1/10 Scale

Fuel Off-road

1/10 Scale

Fuel Off-road Truck

/8 Scale

1

Fuel Off-road (IFMAR Class)

1/8 Monster Truck

On-Road Racing with Nitro-Powered Cars: 1/10 Scale 0.15 Fuel On-road 2WD 1/10 Scale On-road 4WD Open 1/10 Scale 0.12 On-road Fuel Touring Car 4WD (IFMAR class) 1/10 Scale 0.15 Fuel Touring Car 2WD

For

1/8 Scale On-road Fuel (IFMAR Class)

1/5 Scale Super Touring Car (IFMAR Class) 1/5 Scale Sports/GT class 1

ROAR

in

are also

/5 Scale Formula

America and

some

1/8 scale

IFMAR

class

internationally. There

quads and

radio gear)

or Picco

similar-size go-karts

with nitro power.

you with a $1,275 (plus radio gear) on-road car that will hit nearly 70 miles an hour. The 1/8 scale road racers are the fastest model cars on the planet, but that racing class is far more popular in Europe and Asia than in the United States.

1/10 OR 1/8 SCALE ON-ROAD NITRO RACERS Judging by the dealer sales of different classes of nitro-powered on-road cars, it would seem that the 1/10 scale on-road cars are the most popular classes and the 1/10 scale touring is probably the one to pick if you want the broadest choice and the most active

ROAR NITRO RACING CLASSES you are going to race your nitro-power car you will most likely find that track is using some form of the ROAR racing rules and classes. You can see the specifics on the ROAR website. ROAR’s nitro classes include: The If

competition. The .1/10 scale nitro-powered cars range

from $300 MRC/Academy Velox

XT

0.15-engine four-

IFMAR

wheel-drive machine (with 0.15 engine but without ra-

dio gear) to Mugen’s

MTX-3 ProSpec

and a Serpent-brand Mega 0.21 EV03MS racing engine at about $325 will provide

P7R

rules

shown

in parenthesis

mean

that

ROAR es-

car at about

sentially uses the international rules for these classes so

$500 (without radio gear or an 0.12 engine; the $250 O.S. Engines 0.12TZ would be a good choice). The cars should top 40 miles an hour. By contrast, the 1/8 scale Mugen MRX-4 at about $950 (without engine or

you can compete both in the United States and anywhere else in the world at IFMAR events if the car complies with these

53

rules.

Above right: Monster for

Above

trucks are usually just for enjoyment, but there are

machines

left:

like this

RDLogics I/H

Chadd Brockman painted

the

upgraded the model from a

Below: This 1/10

scale nitro

some

rare competition events

scale Wolverine with (1.27 engine.

0.

body on

his

Traxxas

T-Maxx and

15 to a 0.21 engine.

Monster Traxxas T-Maxx has a formed aluminum conversion

54

chassis from Racer's Edge.

Above: Kyosho’s massive 21 -inch-long Giga Crusher has two 26-class nitro engines, four-wheel-drive,

Below: The

1/5 scale radio control cars are massive

by small 23cc lawnmower engines

like this

HPI Racing

55

and

and

DF

reverse.

usually

powered

two-wheel-drive Baja

5B

Buggy.

Above; The I/IO to

scale nitro louring car bodies usually

allow cooling air

to

reach the engine like this

Below: The Team Associated Nitro TC3+

is

hare a massive hole

Team

hi the

Associated Nitro

windshield

TC3+.

a I/IO scale nitro louring car with four-wheeTdrive,

a 0.15 pull-start engine, two-speed transmission,

56

and aluminum

chassis.

Above; The

thick

aluminum

chassis

for the

Below: Some like this

is

one of the dozens of factory team special performance parts

Team Associated Nitro TC3+.

clubs race under rules that specify only overall size

CTS

Cadillac with undersize wheels

57

and

tires to

and body

type,

lower the chassis.

THE TAMIYA TG10-MK.2

A

IS

CHASSIS

KIT

TO POWER A FOUR-WHEEL DRIVE 1/10 SCALE NITRO TOURING CAR Air

Front

filter

Throttle

Rear differential

differential

servo motor

Foam

Drive shaft 1

2 engine

expansion Fuel

li

chamber

Fuel tank

Above; The Tamiya TGIO-Mk.2 is a chassis kit to power a four-wheel-drive 1/10 scale nitro touring The kit includes all the components, with a carbon fiber two-deck chassis, four-wheel-drive, a two-speed transmission with a racing clutch,

58

and

is

designed for a

0.

12 engine.

car.

tire

Above:

Tlie

HPl Racing

I/IO scale nitro

RSR4 RT3 Evo

is

a replica of the 1/1 scale factory-sponsored car behind

59

it.

'"n.-

*'v'S

i.,

-

..

I

,

1

5

CHASSIS

CHAPTER

PERFEaiON hobby-type radio control cars hove chassis

All of the

that ore adjustable to insure that is

doing

its

maximum

to

each wheel

propel the car.

INCH EVERY SURFACE VARIES, EVEN SMOOTH, PAVED PARKING LOTS ARE MARKEDLY different

on

from one another,

a dirt track can vary

as are carpeted

from hour

to hour.

indoor tracks, and the conditions

No model automobile

suspension

up

to the car’s

system can be expected to adapt to changing conditions.

owner

to adjust the car to suit the prevailing track conditions.

MORE PERFORMANCE Let’s

need

you are racing in organized you really must read the rules to be sure that you are allowed to replace stock parts with lighter-weight competition items. There are titanium suspension parts and pieces and a host of carbon fiber chassis plates and brackets, as well as titanium screws and nuts

“hook

available that can significantly reduce

If

begin at the end: You want to go

For more speed you

faster.

will

need

weight or more power; preferably

events,

less less

weight and more power so the more powerful

motor has

around the

track.

power-to-weight to find

less

weight to pull

Given the best possible

ratio,

some way to

you

will also

get the tires to

ac-

the weight of the car. There’s no point

and cornering. For

few grams on a pair of suspension arms. If your goal is to reduce weight, the only sure bet is to replace

up” to provide better traction during celeration, braking,

the

It’s

moment,

let’s

take

it

in saving a

as a given that

you have selected the best possible tire for a particular day. This chapter is about

component possible. The resulting machine will be lighter and it will also be a bit more fragile. If you break someevery

that third variable: traction. Specifically, traction obtained by keeping the tires of your choice in contact with pavement or dirt regardless of whether the car is

thing, the replacement part

is

going to

be far more costly than original. So, learn to drive with stock

accelerating, braking, or cornering.

Opposite: The front suspension

is

bottomed-out as

this 1/ 10 scale

two-vAieel-drive modified buggy hits the face of a jump.

61

components.

The more

offers

costly the car, the

ble.

1/1 0-scale er,

and

the chassis

real race car,

your

larger on-

may

and off-road

this

Tamiya 1/8

with a 0.21 engine has a ball joint

to

adjustment ( upper

with hall joint ends ( lower

and

MP-7.5 buggy

forth lean of the suspension

right), as well as adjustable rollbars

left)

and a

62

milled

howev-

with far more adjustments possible than on passenger car.

full-size

scale four-wheel-drive Inferno

adjust the back

race cars,

be every bit as adjustable as that of a

a limited-slip traction control differential for most of their cars.

The front suspension on for caster

TRUE

more adjustments are possiFor the lower-priced machines, only a few simple chassis adjustments may be possible. For the serious

adding “speed” through spending money. It can be costly. A fully tricked-out car can easily cost $1,000 in addition to the price of the original machine. Given that sobering fact, you might want consider getting the most from the existing machine and learn how to drive it to the limits of its capabilities.

Above: Taniiya

AND

STRAIGHT

and once you have developed both your driving skills and your chassis setup and tuning skills, consider

almninum

chassis.

The

through a corner. Without a differential or with a solid rear axle, one or the other of the wheels (tires) would

adjustments to check are for the chassis

first

alignment. Measure the wheelbase (from the front axle centerline to rear axle centerline) left

side

of the

car.

Hold

on both the

right

have to break traction to

and

tance the outside

a yardstick along the edges of

car

the tires to be sure that tires are parallel even if the front track width also

want

is

arm

for the greater dis-

through a corner.

and on most radio control

On a race

cars, the differentials also

include a limited-slip function that prevents the wheel

narrower than the rear track width. You

to adjust the linkage to the steering

make up

tire travels

might be slipping from spinning out of control. The an adjustment to allow more or less power to be delivered to the slipping wheel.

that

so the

dead straight down the track with your finger removed from the transmitter’s steering

limited-slip differentials have

car will roll or track

wheel. Serious racers

Adjusting the limited-slip feature can have a noticeable

scales so they can

effect

buy four small digital weighing weigh each corner of the car to be sure

on how the car corners. On a track with a high deyou might want the limited slip to be

on the right rear tire is the same as the weight on the left rear and the same left/right weights on

gree of traction

the front. Adjusting the suspension so each wheel carries

fighting the dilferential. Off-road or

that the weight

the proper ing.

slightly loose so the car

amount of weight is sometimes called tweaktracks with more right (or left) turns you

track,

On some

may want

to adjust the chassis to prov'ide a bit

tires are

slide naturally

on a

without

really loose

set the differential very tight

spinning through every corner.

more

SET-UP SHEETS

spend more rime during each lap of the track on the inside of the turns. weight on the

you might want

because both

could

tires that

cars,

the exception of some of the oval racers and toy most radio control race cars have a differential between the right- and left-driven wheels. If the car is four-wheel-drive, it will have a differential on the rear axle and a second differential on the front axle. The differential acts just like that on a real car and allows the

set up involves literally dozens of variables, you will see in this chapter. I strongly recommend that you copy a set-up sheet for your car from the manual or download one from the manufacturer’s website. There are places to record each available adjustment. Once you have the car set up properly, take the car to the track and bring along a half-dozen fresh set-up sheets so you can record any changes you make on a new set-up sheet with the original for reference in case you need to go back to

outside wheel to travel farther than the inside wheel

original settings.

Suspension as

DIFFERENTIALS \X’ith

Above: The

differential

on a model

car, like

that on a real car, allows one wheel to turn slightly slower

than the other so the car can negotiate corners. To

test its action, twist

one wheel and the opposite wheel

should turn freely but in the opposite direction. Courtesy

63

HPI Racing

SUSPENSION VERSUS STEERING

bumps and

The changes you make on

traction.

the suspension can have a

profound affect on how the car steers. Surprisingly, changes at the rear of the car can often have more affect on the steering than changes to the front of the car. Remember, the front tires obtain part of the leverage that provides their grip by pushing against one another and by pushing against the back tires. If the back

they

may

back

tires are

slides

out

is

may have too much much traction to plow or slip. Some more controllable

The

Flextek

RC milled titmiium

tire will

the rubber that

and

bicycle inner tube so the tire

weight of the

car.

The foam

is

able to support the

inserts are usually offered in

arm is also available for the 1/10 scale monster trucks and Revo; IIPI Savage monster; and this Team Losi iST.

suspension

including the Traxxas T-Maxx, E-Maxx,

both on- and off-road radio conhollow rubber moldings. ,The stiffness of

depend on the thickness and hardness of is used to produce the tire. Most of the tires for t|ie rear of off-road cars are relatively soft and actually too soft to support the weight of the car. These softer tires include molded foam inserts that act like a the

if it

shock absorbers that allow the wheels to traverse

Above: The

to force

tires fitted to

trol cars are

,

as the springs

supposed

wheels during hard cornering.

tail first (oversteer).

TIRES VERSUS SUSPENSION The suspension is usually defined

is

must be soft enough to conform to the track surface, and they also have a degree of compression and rebound. The tires should be glued to the rims with a bead of AC cement to be sure they cannot roll off the

drivers prefer a car that slides out nose first (understeer) while others feel the car

what

a large degree of suspension themselves because they

getting too

force the front tires

is

the tires to stick to the track. However, the tires provide

tires are slipping, the front tires

grip; or if the

other surface irregularities losing minimal

The suspension

64

a varien' tire

also try using

foam

Whenever foam rubber

of different hardnesses so you can adjust the

pressure by fitting softer or firmer foam.

inserts.

feels like a

some of

You can

the harder tires without their

Usually the foam

coarse sponge.

It is

is

white and looks and

shape.

change the

tire’s

foam

insert to

for example,

you want

the shape of the

performance.

If,

m

foam inserts for random air pressure,

a square or flar-tread-surface tire to provide a bit less

the air pressure. Several firms offer

grip at the edges to reduce the chance of the car rolling

these tires so the foam, rather than

over, trim the

edges of the

edges of the foam insert so the extreme

tire’s

will

support the

car.

tread are unsupported.

Above; The Tamiya

a

Some makers also offer foam inserts for wheel/tire combinations that are designed to rely just on the tire’s rubber stiffness. Some tire/wheel combinations have tires that fit tightly on the rims to form an air-tight seal. With these designs the trapped air acts to stiffen the tire addition to the built-in stiffness of the tire itself. There is, of course, no way to increase or decrease

match most tires. Try to buy foam precut to fit your tires. If you cannot get the exact size, try to at least get the exact (plus or minus about 1/8-inch) inside diameter and use scissors to trim the outer side to match your

You can modify

on

rubber compresses.

precut into barrel shapes

to

tires’

inserts are installed

wheel designed for a rubber tire, you will need to drill a 3/16-inch hole in the inside of the wheel to allow air to escape and reenter the tire as the foam and/or the

1/ 10 scale nitro

four-wheel-drive

TGIO-Mk.l

has fully adjustable suspcusiou geometry.

65

chassis

GETTING A GRIP Too much

dictable rollovers. car spinning track.

The

track even during severe cornering.

traction can lead to wheelies

its

tire’s

Too

little

and unpre-

tually slide

The

car should even-

the tires lose traction, not roll over.

The

design principles used for real automobile suspension

traction literally leaves the

down

when

the

have been applied to radio control model cars because

tread pattern, as well as the softness or

those same principles work in 1/12 or 1/6 scale as well as

wheels rather than progressing

grip of the rubber

itself,

they do in 1/1 scale. There are

provides the grip between the

we

and the paved track or dirt. There are hundreds of differguide. Find out what they use and try it, but also try a tire that is both harder and/or with a less complex tread pattern and a tire that is softer and with a more complex tread pattern to see if the norm is good enough or if you need more or less traction. There’s a reason why all full-size cars and most radio control cars have suspension systems and it’s not just to provide that bounce. The suspension is supposed to allow the wheels and tires to follow the road (or off-road) surface without hopping or skipping. The suspension is supposed to keep all four wheels in firm contact with the tire

Above: The

rear suspension on the

and

UK) scale

Losi

some

variations because

are dealing with vastly lighter machines, but those

differences have been factored into the design of every

radio control race car chassis.

The springs keep the car from dragging on the pavement or ground. By choosing the lightest and/or shortest practical springs, the car can be as low as possible for the lowest possible ride height

center of gravity. Ride height

when

it

sitting

on

its

is

and lowest

the set the car takes

springs with only the weight of

the car (ready to race with batteries and/or a

of

fuel) resting

gravity, the less

XXX-4

on the

chance there

The lower

is

full

tank

the center of

for the car to roll

has been upgraded with aftermarket ball joints

drive shafts on Reggie Sarator's modified class racer.

66

springs.

and

the cornering forces can be to provide If

more

more

effectively

channeled

traction.

the springs are too soft, the car will

roll.

does reduce

its

manual that

is

much

If the

preload

effective travel before

it

bottoms. The

furnished with your car will is

optimal for your

tell

car. Start

you how with the

most of the

cor-

stock setting on each coil-over spring/shock unit.

nering (or the landing forces after a jump) then the

tires

off-road racers

maximum

trac-

suspension for about 1/3 of its total travel and adjust the preload (and/or change springs) to provide that initial

springs are just stiff

enough

to absorb

can retain their most effective profile for tion.

You can

how

test

far the

spring moves by wrapping

a tiny zip-tie tightly

setting. If you find the car

sorber and slide

might want

sorbers.

around the shaft of the shock abup near the top of the shock abRun the car at racing speeds and take a look at it

the zip-tics to see

how

have been forced to ties

down the shaft move. Remember to cut far

You can tighten the threaded

That inward angle allows the suspension arms to more pressure on the shock/spring unit, effectively producing a softer spring and shock. Moving the top of the shock/spring unit inward also increases the

to

check

Gauge

how

of how much as

rate or progression

the unit functions. Leaning

the top inward as

possible provides the maxi-

mum amount of resistance at the bottoming end of the suspension action, which can be useful has rather large jumps or

if

a dirt track

you are racing on a rough paved parking lot track. Changing the position of the top mount can be a quick way to a softer or firmer

collar to partially

CVEC Droop

mounting po-

exert relatively

compress the spring to prcivide more preload. Compressing the spring does not really make it stiffer, but it

Above: The

radio control race cars, the

inch.

minimum amount of pre-load

possible.

be the

will

of the shock absorber/coil spring unit can be positioned in a choice of three or more holes. Each hole angles the shock inward a fraction of an

and can get tangled up inside the springs. You can adjust the springs by fitting stiffer or softer springs. However, on serious race cars with coil-over shock absorbers (coil springs that are wrapped around the outside of the shock absorber) you can also adjust the springs by adjusting their preload. The better shock absorber will have a threaded body with a threaded ring to retain the spring. Remove the threaded ring to replace the spring. W'hen you install the ring you can thread it onto the spring just tightly enough so there is some rewill

it

try a softer spring.

sition for the top

travel

which

you might want to

On many

off the zip-

before racing because they will limit the suspension

sistance,

runs best with no preload, you

to try the next stiffer spring. Conversely, if

the car runs best with the collar tightened as far as go,

the zip-ties

Some

that the vehicle should compress the

feel

suspension

set up.

includes two parallel bars to support the car

far each of the four

67

hubs

if

rests off the

ground.

and a gauge

IS IT

With

DROOPING possibilities

YET?

identical.

of providing more or

less

preload and

droop

shock mounting positions, you can easily upset the balance of the chassis. Usually you will want the right and left sides of the car to have the same amount of travel. You can measure that by elevating the chassis on

be the same on the

different

a 6-inch-high block or canister so gling freely.

Remove

all

right

right

and

and

left,

amount of

the

will want it You may have to

but you

right sides.

It is

best,

though, to turn both

slacking the right a turn

and

and tightening

left.

More droop can allow

from the bottom of each front axle to the ground on the right and on the left. Usually you will want those two dimensions to be identical. Repeat the measurements at the rear, right, and left. Again, you will want those dimensions to be

vernier caliper) to measure the distance

the steering response

the tires to get

may be

less.

more

grip,

but

Generally speaking, on

the slicker surfaces, less droop should allow the tires to

have better grip.

On

surfaces with greater grip, less

droop may produce more speeds through the corners.

CVHC Ride Height gauge provides an left

left

rear,

the left a turn (or vice versa) to balance the difference

the four wheels so you can see the

and

and

turn the shock absorber collar on one of the shock ab-

four wheels are dan-

of the right

may not want

or

sorbers to adjust droop.

suspension. Use one of the droop gauges (or a ruler or a

Above: The

You may

to be identical front

accurate measurcmcut of the distance

and front and

68

tire

rear of the car.

traction

and greater

ADJUSTING THE RIDE HEIGHT The the

ride height

is

the distance between the chassis and

ground when the

ready to race.

It is

car

is

on

resting

its tires

and

is

the natural position the car assumes

bouncing up and down a bit. To check the ride bounce the car up and down about three times on a perfectly level surface and let it rest for a moment. Pick a specific point near the front at each corner and another at each rear corner at the places where you will measure ride height for each specific car. Measure the distance from those points to the tabletop at each corner. The car will perform its best if the ride height is equal from left to right on the front and from left to right on the rear. Generally, the best performance occurs when the ride height is level from front to rear, bur check it on the left and the right to be sure one after

height,

corner

is

not sagging.

You can sometimes

raise the ride height by fitting (matching right and left, of course) or lower the ride height with smaller tires. Remember that changing the tire diameter on the driven end(s) of the car effectively alters the gear ratio so you may want to

larger tires

change gears as well. On most cars, the only way to change the ride height is to tighten the spring preload to raise the ride height or loosen the spring load to lower the ride height.

On some

you may be able to inshims between the suspension and chassis

cars

sert

to lower the ride height

or remove shims to raise the ride height.

You

want the

will

lowest ride height possible

when

the traction

On

at its best.

is

loose sur-

ride

you may find betby raising the height. More droop

will

also

faces,

ter traction

height

Some late

the ride

raise

of the chassis.

racing rules stipua

height,

minimum you

so

maintain that ride height

minimum

when you

just the chassis.

Above: The threaded

Below: You can

test

collars that retain the springs

on the Tainiya TGlO-MK.l can be used

the efficiency of the shock absorbers by by pushing

69

down on one

to

increase ride

and

ride

must

height.

corner of the car to bottom out the suspension.

ad-

SHOCK CONTROL

nTore or less flow.

The shock absorbers also help control how far the car will compress on its springs. Without a shock absorber the car will try to force the spring to full compression on every bump. The shock absorber, however, provides a hydraulic fluid damping action to control just how rapidly the spring compresses. Thus, sudden hits are taken up by the shock absorber and to some degree, transferred to the tires. The shock absorber is a round chamber that is attached to the chassis at one end. The chamber is filled with oil. A pis-

you

ton

attached to a rod that

is

The piston

that slides

will force its

is

way through the

On most model

have to

dovv'n inside the

chamber

fluid. Carefully

designed

the surface. Conversely, the lighter fluid allows the tires

how

to

respond more quickly to big

quickly the fluid can travel through the piston and, thus,

ditions where you

how

spring with lightest

absorber

A

is

compressed and

car shock absorbers changing the fluid in-

shock absorber to provide more rebound and more compression dampening by using a thicker fluid or less rebound and less compression dampening by using a lighter fluid. The effect of changing to thicker or thinner oil is similar to that of changing from stock to stiffer or softer springs. As a general rule, you would want to run relatively thick fluid on a smooth track and relatively thin fluid on a really rough or bumpy track. The theory that the heavier or thicker fluid keeps the tires from overreacting to the slightest irregularity in

holes (and/or flapper valves) in the piston determine

quickly the piston can

settle for

side the

connected to the suspension.

up and

will likely

rise or fall as the

shock

might want the

released.

few of the model car shock absorbers have dual-

softest possible spring with the thickest

dampening on the compression stroke than on the rebound stroke.

to the stock spring

These pistons can be replaced with other units that offer

lighter or softer spring.

to

normal

and shock fluid. Start tuning by aland if that works, try a

tering the spring pre-load,

release the pressure that

should spring back

There are track con-

or heaviest possible fluid. If you get confused, go back

stage pistons with a different degree of

Above: Quickly

hits.

would want the softest possible fluid and other tracks where you

bottomed out the suspension and the car

ride height with only

70

one or two rebound bounces.

ANTI-ROLL BARS

may

The more sophisticated radio control clude another element that biles:

an anti-roll

bar.

The

common on

real

automo-

anti-roll bar helps

keep the

is

from rolling or tilting as much through corners. Most anti-roll bars are simple pieces of wire that are connected to the moving parts of the suspension on the right and left and to the chassis in the middle. The antiroll

bars are designed to allow both the right and

striction.

farther rolls

If,

tries to

does when the car

combinations

an anti-roll

bar.

You may

also need to readjust the

to

compensate

ally

for the effect of

an

anti-roll bar.

having a rear anti-roll bar. It is

also possible to adjust the roll center

radio race car chassis.

The

roll

center

is

moves up and down during heavy cornering grip, especially

on smooth paved

center can he adjusted by adding or removing shims from the inner

tracks.

HP! Racing Pro

4 l/IO scale touring car

71

chassis.

mounting

and the lower A-arm mounting Courtesy HPI Racing

for the top suspension link or from the bottom suspension mounting between the chassis

on the

loads. Rais-

ing or lowering the roll center can provide a bit

Roll Center Centre de roulis

like that

on some

the imaginary

point where the wheels pivot inward as the suspension

movement

and help keep the car level. There is usually a choice of mounting positions to pro\'ide more or less anti-roll effect, or you can substitute a stiffer or softer bar. There

roll

Gener-

(but not always) a two-wheel-drive on-road car will

wheel-drive off-road truck or buggy will benefit from

an

Above: The

is

spring preload and/or go with a softer or harder spring

move

a fast corner), the anti-roll bar provides

additional spring to stiffen the side-to-side

tire

benefit from having a front anti-roll bar while a four-

or

it

and

re-

tilts

(as

specific tracks

left

together with no

however, one side of the car

up than other

during

down

some

removed. Conversely, some cars that are not fitted with anti-roll bars can corner quicker with the installation of

car

suspensions to move up or

even be

that will provide better cornering if the anti-roll bar

race cars often in-

more

Above

left; The

RPM aunber gunge has an adjustable face so yon can

the degree of positive or negative

Above right: The Mohr Racing camber gauges the toe-in at 0.5,

Bellow:

On

this chassis the

1.5,

camber

measure

at each wheel.

are three simple plastic plates that indicate

or 2.5 degrees so the suspension can be adjusted to match the angle on the gauge.

I'he

manual supplied with

upper suspension link

is

the car will

show you where

to

a hexagonal rod that can be rotated to

72

adjust the camber.

move

the top of the tire in or out.

CHASSIS The

AND STEERING GEOMETRY

forces that allow the car to corner at the

radio control car designers have developed each specific

maximum

chassis to provide the

geometry here rear tires

ward full

is

that of controlling

and wheels

how

will lean in, out,

as the suspension

moves from

into a winner.

for-

little

SETTING THE CAMBER when you are looking dead-on

ad-

than inserting or removing shims be-

tween the axle or suspension mounting bracket and the chassis.

The

camber

serious racing cars have adjustable every-

Positive

thing from track width to anti-squat. Fortunately, the

Above: The

On

steering pivots

a four-wheel-drive car like

Those small

compression to

rebound. Again, the lower-priced cars have

justability other

so the adjust-

are relatively small.

adjustments are the ones that can make a so-so chassis

far the front or

backward, or

full

optimum handling

ments that can be made

edge of traction are determined by chassis geometry. The

this,

on a

and

left

the angle that tires have

vertical kingpin with ball joints top

the drive shaft

and

at the front

and bottom.

universal joints are usually located in the kingpin as well.

73

of the

car,

compared to vertical. camber means that the bottoms of the right tires are closer than the tops. Negative camber

is

means

that tops of the right

apart than the bottoms of the

and tires.

left tires are

When

with

farther

the car

is

1

setting

cor-

degree and again with 0 degree and see which

works best

for you.

toward the outside of the corner. By having a few degrees of negative camber, the

SETTING THE CASTER

leaned-over car actually positions the inside

That imaginary

nering

It

will usually lean a bit

near-vertical position,

have

maximum

which allows the

it

a

it is

from the

more important

maintain contact than the outside

will actually lean

it

a bit

more during

tire,

is

which

this corner.

is

the pivot point for the steer-

On

when viewed

That amount of backward or forward lean angle, which forces the wheels to want to

side.

the caster

The angle

travel straight ahead.

positive caster

when

it

is

considered to be a

leans toward the rear of the car. If

you move the top of the axis forward from vertical you would have negative caster and the wheels could wobble like those on a shopping cart. Caster is usually set as a

most radio control race cars you’ll find the most front end grip with between 2 and 4 degrees of negative camber. Experiment a bit and you’ll discover that the car will stick better as you add degrees of negative camber until It reaches a point where the last adjustments completely ruin the handling. That’s when you go back to

positive with top of the imaginary center line leaning axle. An off-road car usually much more caster to maintain a steady course down that bumpy track, so the caster will likely be set

'backward toward the rear requires

the previous setting.

Most

line that

ing can also be leaned forward or backward

tread to

grip. Since that inside front tire carries

most of the load during cornering, that

tire’s

tire in

somewhere between

radio control cars also have independent

5

and 20 degrees

for a four-wheel-

suspension for the rear wheels rather than a solid axle (like some of the oval racers with sidewinder

drive truck or buggy, a two-wheel-drive truck or

motor/axle units). You can usually adjust the camber on these suspensions. Again, try the car with 2 degrees of negative camber at the rear and then try it again

smooth

Above: Negative camber means

may

(xHirtesy

surfaces of paved track allow

caster angles, so

most on-road

cars have

much

in,

while positive camber

HPI Racing

74

means

shallower

between 0 and 6

degrees of positive caster.

that the tops of the tires lean

buggy

have between 20 and 30 degrees of caster. The

the tops lean out.

anti-dive. Anti-dive allows the

braking action to be

dissi-

pated into the chassis without forcing the front of the car dtm'ii onto the springs. er,

Too much

anti-dive,

upsets the caster geometry and the car

down

howev-

may wander

the straights and/or not have the precise control

you want

for the corners.

SETTING THE ANTI-SQUAT The suspension

links that control the rear wheels can

also be set so the wheels

move up

or

down

at a caster

angle as viewed from side. At the rear, however, the

term is

is

anti-squat.

shifted

tires.

When

the car accelerates, the weight

somewhat from

When

the weight

is

the front tires to the rear shifted, the rear

wants to move down or squat, whether driver 1/

1

it’s

of the car your daily

scale car or a radio control race car. If the rear

up so the rear wheels and tires move (when viewed from the side), the car is said to have 0 degrees of anti-squat. By inserting shims between the chassis and the front of the rear suspension mounts you can tilt that angle back 1 or 2 degrees

suspension

is

set

exactly vertical

to induce anti-squat. In action, that angle helps resist

on accelersounds great but it can have some strange effects on the car’s performance because there may be less traction when the car is in a braking mode and the weight is transferring to the front. That shift can allow the rear end to break traction much easier than with no the tendency for the rear of the car to squat

ation.

SETTING THE ANTI-DIVE Some

radio control race cars also have adjustments for

the front suspension

ing pushed

down

arms to help the chassis

at the front

resist be-

by the weight transfer that

It

occurs during heavy braking. Front suspensions that

anti-squat. Again, you’ll have to try

help keep the car level during braking are said to have

improve the cornering speed on a particular

Above: The

to see if

how well the car will self-correct when coining out of corners and how well it will track HPI Racing have four different uprights, but you can shim the front or rear suspension mounting on other cars to produce more or less caster angle. Courtesy HPI Racing

caster angle influences

the straight.

The Pro 4

cars from

Below: Adding or removing shims from sis

the suspension

mounting points on

the

HPI-Racing Pro 4 1/10

allows you to adjust the anti-dive on the front suspension. Courtesy

75

scale touring car chas-

HPI Racing

it

car.

Front Vorne Avant

Front Vorne Avant

down

it

helps

TOE-IN AND TOE-OUT when you view a car or truck from outer edges of the front and rear allel

and

the right and directly

tires will

overhead the

straightaway.

The wheels

The

usually be par-

directly in line with the vehicle’s path

down

box

a

That

slight

V-shape in the wheel’s alignment

ferred to as toe-m. If the suspension

ner edges of the

tires are farther

edges of the rear of the

is

justments.

more

is re-

adjusted so the

and

electric

A

stable

slight

on the

amount of

toe-in will

touring cars will also have adjustments for the anti-squat on the rear

and

the chassis like those

on

this

HPI Racing

use a rule to measure toe-in or toe-out by comparing the outside edge width tires to

make

the car

straights but just a bit less responsive

Courtesy HPI Racing

of the front of the

that

1 or 2 degrees of works best but you can experiment with 3, 2, 1, 0, and minus- 1 (toe-out) degrees to see which works best

suspension by adding or removing the shims between the suspension

Below: You can

arm

toe-in

tires it is referred to as toe-out. If

scale nitro

arms that connect from the steering

turning into the corners. Usually just

in-

apart than the inner

Above; The most sophisticated I/IO

steering

to the Tront suspension kingpins or uprights have

can be turned in or out to obtain toe-in or toe-out ad-

tires

are closer together than the inner edges of the rear of the tires.

paralleTto one another

adjustable ends or a turnbuckle-style steering

can, however, be adjusted to

point inward slightly so that the inner edges of the

left tires really are

the vehicle w’ould have zero toe.

the outside edge of the rear of the

76

tires.

Pro 4

car.

Above: With toe-out

Below: With

the front edges of the tires are farther apart than the rear edges of the

toe-in the front edges of the tires are closer together than the rear edges of the

77

tires.

Courtesy HPI Racing

tires.

Courtesy HPI Racing

for

your particular

radio control cars

The range of adjustment on most between those degrees.

rear-wheel steering effect can be used by adjusting the

car. is

toe-in to allow both front

Usually you will want the rear wheels to have zero toe.

You may, however,

around corners with a

find that the car

is

The Hudy

quicker

on-road cars

Try adjusting the rear suspension to provide 2 degrees of toein. If

that works, try 3

bit

of toe-in at the

and 4 degrees

rear.

to see if there

rear tires to obtain bet-

all-in-one set-up solution for 1/8 scale

is

a chassis set-up jig (platform) with

blocks and clamps to lock-in the chassis so you can use the built-in measuring tools to measure

is

any improvement. The rear suspension can actually provide some rear-wheel steering because the geometry changes as the car rolls slightly into the corner. That

Above: This

and

ter traction.

all

the chassis

adjustments without moving the car from the special jig.

A

similar unit

on-road

is

available

from Hudy

cars.

RPM toe-in gouge has small notches at the right edge so you can see if the difference between the width at the front of the tires differs from the width at the rear.

78

for 1/10 scale

Above: The

steering

geometry on

this

2WD modified buggy

is

adjusted so that both wheels lean into the corner.

If you look closely you'll see that both front wheels are skidding

through the dirt as they grab for traction.

79

a smooth path

OVERSTEER when you

AND UNDERSTEER

have perfected your driving

adjustment, you

may want

to consider

"Some skills

and

some options

drivers can get

the corner with

most

four-wheel

tires

cars so that the car will corner with the front tires

more than

rear wheels sliding a bit

car slide

around the corner,

easier to drift a car

around a corner with the

than

adjusted to provide understeer.

is

adjusted to provide oversteer

Above: The HPI Racing R40

around and rear

this

is

called a

caster are the

most

effective is

suspension sliding too

one end or the other. The chassis may also need droop and/or ride height to improve the traction at the front or the rear of the car as you desire. The weight distribution can also affect which end of

tail

is

front

drift.

at

to be adjusted for

out when the chassis the chassis

on the

much

(four-wheel drifting).

if

corners, while other

adjustments that can correct a car that

(oversteer), or

with both front and rear wheels sliding about the same

It is

most

little visible sliding. If both

Camber and

the rear (understeer), with the

more than front

a track faster with the tail of

drivers are quicker if all four wheels are tracking

for

improving your lap times by making additional fine adjustments to the chassis. You can adjust the chassis on sliding a bit

around

the car drifting out through

chassis

the car

is

likely to slide the

nitro I/IO scale touring car, like their electric Pro 4 chassis,

80

is

most.

fully adjustable.

WHEELBASE The

On some

radio control race cars

a wheelbase

and

handling for that parasitical

rules

may

overall) erally,

ble

car. Also,

weight distribution of the

the racing

width so you cannot make major changes. Gen-

more

On some of the more sophisticated

the car’s center of gravity will be visible if you actually

but

it

will

move

moved

forward. Obvi-

control

when you

Some brands change

in

if

81

you

feel

how it

make minute adjustments

Courtesy

like those

HPI Racing

on

easy the car

though the

car,

is

to

corners.

and longer chassis that you you need to make a major

weight distribution.

racing chassis you can

chassis.

are driving

offer shorter

can substitute

4 1/10 scale touring car

weigh the four corners of the

can make a difference in

by adding or removing shims from the pivots joints

HPI Racing Pro

it

ously these are minute adjustments that will barely be

and rear track widths. The significant factor here is the ratio between track width and wheelbase. You can effectively increase the wheelbase by narrowing the track width. If the chassis does not have the option of changing the track width, you may be able to find wheels that are slightly offset to provide a slightly wider or narrower track width than the original wheels.

in the wheelbase

you shorten the

en the wheelbase by moving the front suspension back,

sta-

assuming both chassis have the same front

Above;

If

the car’s center of gravity toward the rear. If you short-

but more difficult to turn than a chassis with a short-

er wheelbase,

car.

wheelbase by moving the rear axle forward

stipulate a particular wheelbase or track (or

a chassis with a longer wheelbase will be

you can adjust the length of the

pension. Changes in wheelbase can also affect the

and a track width that provides the best pos-

sible

cars

wheelbase by adding or removing shims from the sus-

chassis are designed with

this

6

RACE CAR PREPARATION ELECTRIC

CHAPTER

Any radio

control cor will take

owner/driver

if

is

it

some core from

to deliver oil the

performance

makers intended. There's always on urge

its

more power and performance, but

its

it

oil

for

starts

by getting the most from what you've got.

ANDS-ON HELP FROM THE PROS Folks that race radio control cars are gearheads by definition.

would want such urge to

make

it

appear because

a complicated mechanical device?

better. it is

and you’re only able to leave

it

But that car

is

to see

it

at rest.

to tailor

it

and make

m

might

motion is

it.

to develop their cars

and suggest

specific

any radio control car

changes that can be made to match the

to specific track conditions

car to different types of tracks. Most of what you want to know is in the manual. If what they suggest does not work, read

to

easier for

through

the instructions. All radio control car

and

manufacturers pay professional drivers

are

OppositeiA is

when

it

The advice you probably won’t follow

you to drive. The toughest part of the whole hobby is learning that you really do need to read it

else

have this insatiable

a device designed to function at its best

alone until you learn to drive

made

all

even more complicated than

There are some basic adjustments that can be

We

Who

1/ 1 0 scale

this

book, talk to your dealer,

talk to racers at the local track that

running the same

car.

modified truck, after recovering from a jump,

diving into a left-hand turn on the

RC Madness

83

track in Enfield, Connecticut.

CHASSIS FIRST The

TIRE CHOICE Replacement tires

and most important chapter in this book is Chapter 5, Chassis Perfection. The information on setting up the chassis applies to both on- and off-road cars largest

in all scales. all

Some of the

may not

lower-priced cars

for

Most

running the same car you

racers are willing to share

enough

basic

information for a newcomer to get his or her car running to near-perfection.

The

last bit

of cornering speed or

power that you might consider a “racing secret” is information you won’t need until you have learned to drive a perfectly set up out-of-the-box machine. There is additional information on selecting motors, troubleshooting motors, and selecting gear ratios for electric-powered cars in Chapter 7.

Above: This Team

Losi

XXX-T Sport

The Team Losi XXX-S l/IO

scale

of the radio control cars that are designed to be Some of the more readily available racing tires

are

formation are the folks that are actually running at the race.

and

made by Team Associated, Team Losi, Pro-Line, Schumacher, and others. There is usually a choice of hard, medium, soft, or super soft for any car that can be raced under the ROAR rules and classes. There is even a wider range of tires available for the off-road monster trucks. Try to fit replacement tires that are the same diameter as those on the vehicle. Changing tire size will effectively change the gear ratio as described in Chapter 7.

of the adjustments suggested, but adjust what you

track, especially if they are

all

raced.

offer

can as suggested in that chapter. Your best sources of in-

want

with, different tread patterns

different degrees of softness or hardness are available

OFF ROAD TIRES There

is

usually a choice of hard,

soft tires

Truggy off-road chassis

is

fitted

from the major

with

Team

Losi’s taper

pin rear

4WP touring car chassis has slick-tread tires with foam

84

medium, soft, or super The hard tires

tire suppliers.

inserts.

tires.

would only be used on a wet and muddy track or on grass. The medium-soltness tires can be useful if the

work

able degree of traction

on cars that slide very little because they hook up or grip rather than slide. Conversely, if the fastest way around the track seems to be a series of powerslides, the rounded profile tire will work best. The rounded profile allows the car to slide without

work

catching the edge of the

track

is

are the

partially

most

muddy

versatile

or in loose sand.

The

tires

soft tires

because they will provide a reason-

on almost any surface, but they on well-packed surfaces. The super-soft tires will hook up best if the track has a hard surface with virtually no loose dirt. Some tracks are hard enough that rubber worn off the cars’ tires is visible along the racing line in what is called a blue groove by both radio control car racers and the folks that race fullsize cars on dirt ovals. The blue groove can appear on an off-road track, like the Rat Raceway in Chapter 14. You will probably have a choice of tire profile, as well particularly well

rubber hardness. Generally, the choice

is

best

allow the car to

There

is

On a two-wheel-drive car you will want to run a different tread pattern on the front than on the rear. For a four-wheel-drive car you can use the same tread pattern and hardness as on the rear, but you may want to experiment a bit to see if you can get more speed with slightly different tires on the front than on the rear. Be sure to use the same diameter tires front and rear on a four-wheel-drive machine to keep the pow'likely

between a

er balanced. You’ll

and a rounded-profile tire with the width of the tread in a gentle curve. The square-profile

tires like

tire,

Above: These Trinity

tire

Tire

warmers can help

if you

the car.

road cars and trucks.

square-profile tire with the tread nearly flat across the

width of the

tire to flip

also a wide choice of tread patterns for off-

Team

probably have a choice of micro spike

and blue groove

surfaces,

can keep them on until the race actually

warmers are shown here on Pat Byrne’s 1/10

85

scale electric

work best on hard-pack and fuzzy tires like Team Losi’s

Losi’s Sprint that

starts.

Tamiya 1994 McLaren FI

car.

Big Shot that work well on work on hard-pack tracks

enough

that are loose

spike tires like

Team

to create a dusty surface.

Losi’s

Rear

tires for

off-road radio control cars are usually

designed to include a foam

Mini

IFMAR stud should hook up

compound

tires

may not

insert.

Some of

and wotk under track conditions with broken-up and loose surfaces. Step pin tires are a compromise pattern that should work well on anything except blue

have a white foam plastic donut inside the

groove tracks.

ON-ROAD

well

more information on foam

Most on-road

ing cross-tibs to minimize the flex of the circumferential

sliding

you can match the hardness of the front tire to what you have chosen for the rear tires. The unsupported rib patterns work best under most track conditions, but you may want try a pair of supported rib

the correct hardness of the

ribs.

tires

front tires

is

mount

the

motor parallel

and

cars, like this

nering grip

Team

Associated Factory style

is

critical factors in getting

to have perfectly

in-

round

tires

more

cor-

so the car

than hops, around the corners. The solid

Team RC102L4

oval

pan

car,

with the pinion gear on the motor shaft

the spur gear on the axle shaft, but no transmission, clutch, or gear cover.

86

with foam

car.

One of the most

back axle sidewinder

that are similar in tires

around on the pavement makes the selection of foam insert more critical for

slides, rather

to the

tires

greater heat generated by the on-road tires

an on-road

especially hard-packed.

Above: Most two-whecl-drive

The

There’s

5.

and track conditions you can

design to the hollow rubber off-road serts.

tire.

Chapter

simple foam donuts with no tread

cars

choose from a range of on-road

Generally,

of the track

tires are

some

pattern. For

inserts in

TIRES

on a two-wheel-drive car do not have transmit power. They simply need to change and hold the car’s direction of travel. The most common tires have four ribs running around the circumference of the tire. There are also some tire choices that have some support-

The

the hard

use an insert, but most will

foam

tires for

You can determine a battery or battery pack’s power-per-pound by dividing the watt-hours the battery provides by its weight. A battery analyzer can be extremely useful in determining not only how many watthours are available, but how quickly that energy is dissi-

on-road cars are usually sold with slightly

These rues are designed to be glued to the wheel and cut to size and perfect roundness on a small lathe. Your local radio control shop may be able to install and true new tires. Preassembled and oversize outside diameters.

truetl tire

and wheel

than buying new

sets are

not

much more

pated at a given load.

expensive

and paying the labor to have them installed and trued. 11 you race frequently, you should consider purchasing your own Corally or Hurdy tire lathe, but expect to spend between $400 and $550. The tires for ROAR-sanctioned on-road races are available in tires

SUPER-LIGHT SUPER POWER BATTERIES Battery weight is as much a problem as battery life for a model race car. A few years ago, the common Nickel-Cadmium (NiCad) was the best

The green dot is the standard medium-compound tire. The yellow dor compound is soft but can wear out in a lonv race. The blue dot compound is the hardest and may be necessary to last the duration of a race on an especially rough surface. Tire-treating compounds are available that can help

pow’er-to-weight.

three different hardnesses.

dride

is

a place to store energy. For

you want the

maximum amount

model

NiMH

tice

and

terms of

become

available that

the

SCRC

NiCad

batteries for prac-

batteries for the actual race. Currently,

and the

batteries offer quick recharge times

going to race the

ot course,

powers the

amount of weight. The consumed mostly by the electric mo-

car.

car,

check with a sanctioning group to

be sure the batteries you want use are permitted for your

of energy

available with the least possible

tor that

in

Nickel Metal Hy-

highest performance for radio control cars. If you are

Essentially a battery

is,

batteries have

use the relatively inexpensive

BATTERIES

energ\'

recently,

produce the same power with much less weight. The model race car industry has developed the NiMH battery packs and matching chargers so they produce the performance that makes an electric-powered model nearly match the best nitro-powered cars. Some racers

increase the tires’ grip and prolong their wear. Before you buy a tire-treatment tliiid, howev'er, be sure that it is allowed under the rules that will be in force where you race.

race cars

(NiMH)

More

racing class.

Most of the electric-powered

Although the servos that control

to be

model also draw momentary amounts of current, it primarily the motor that needs the power. Rechargeable batteries are part of our everyday

powered by a

set

of

race cars are designed

six batteries,

although the

the

smaller 1/12 scale cars race with a four-cell pack.

is

batteries or cells are wired in a series to provide

to

produce a battery pack that is called a stick. Typically, produce 1600 mAh at 7.2 volts using

a set of six cells can

NiCad

can be recharging while you race with the second.

is

six

mulated 7 to 8 volts. Four batteries produce between 4 and 5 volts. The batteries are electrically connected with soldered heavy-duty wire and encased in a plastic sleeve

The rechargeable battery has also revolutionized model car racing. The battery chargers are now fast enough so you can recharge about as quickly as the batteries discharge. Purchase two battery packs and the first lifesnde.

Above: The parallel wiring system

The

an accu-

batteries or

3300

mAh

at 7.2 volts using

used for the batteries in most electric-powered radio control

87

cars.

NiMH

batteries. All the

major car manufacturers and some acThe manufacturers connect

teries for the transmitter

and a second to charge the batpower the electric motor and radio control gear inside the car. With today’s electric-power race cars, one battery pack is usually used to power both the motor and the radio control receiver, ESC, and servos.

cessories offer battery packs.

teries that

six batteries and shrink-wrap them into battery sticks with plug-in connectors.

There’s a choice of stick pack batteries from

1600mAh and ISOOmAh up can

3600mAh capacity. The own battery packs so they

to

professional racers build their

CHARGING NICAD AND NIMH

and recharge individual cells to find the cells with highest output and predictable discharge rates. The best six are then custom-soldered into a stick. Unless you are competing with pros it’s not worth the test,

discharge,

trouble for the marginal tion.

amount of extra power

The most expensive

The

or dura-

battery sticks are assembled by

is

far

of peak detect charger that can charge up to 18 NiCad or

m radio control model airplanes. The Li-Poly

The Hobbico Triton, DuraTrax Piranha and ICE, LRP’s Pulsar, and Model Rectifier’s Super Brain 969 Pro are all designed to charge NiCad or NiMH batteries. The batteries will produce more power if they are slowly and completely discharged. Your dealer can order special charge and discharge units. Novak’s Smart Tray and Flatline, Duratrax 20A discharger. Venom’s dis-

and the danger of explosion from imtoo great to use them in model race cars.

BATTERY CHARGERS You

will likely need at least two battery chargers for your electric-power radio control car: one to charge the bat-

Above.

I

and

protection for

NiMH battery cells with up to 5.0 amps of charge current.

(Li-Poly) batteries are even lighter

batteries are volatile

pact

BATTERIES

fail-safe

must also apply some common sense. If a battery has become dented, water-soaked, or damaged in any way, do not use it and dispose of it properly. Never attempt to charge a damaged battery. Often the batteries will be quite hot after a race from the relatively rapid discharge. The batteries must be cool to the touch before charging. \ou can speed up the cooling process by buying a small 12-volt fan. The Astro-Flight 1 lOD is one example

batteries are matched for equal performance before being connected into the battery stick.

and are used

some

charging, but you

the factory with batteries that have already been forced through a series of charge and discharge cycles and those

Lithium Polymer

battery chargers offer

here s wide choice of replacement battery stick packs that can provide longer cycles between recharges like these 1.600 and 3,600 packs

more power

from LRP.

88

charger,

can

all

and Yokomo USA’s Rayspeed Exceed discharger

be

programmed

for effective discharging.

racers recycle the batteries

battery

Some

and your physical

self

from rapidly discharging

batteries to determine their performance. Experienced

once a day for a week before

racers feel that the

maximum

temperature for a rapidly

discharging battery should be no more than 140 degrees

any major race to improve the batteries’ performance.

Fahrenheit (60 degrees Celsius). Stop any performance

BATTERY TESTING

tests

There are several battery analyzers available to help you

With computer programs like the West Mountain Radio CBA, you can create individual specification and

determine

how any

given set of batteries will perform.

Mountain Radio computerized battery analyzer (CBA) provides line graphs to show the potential battery power with amps, volts, watts, and amp-hours so

The

performance

Vi'est

the

The CBA includes the hardware

files for

battery reaches that temperature.

each of your battery packs. Label

with the date of purchase and update them in

battery pack.

to connect the

the battery

The

is

dates will help you determine

maintaining

its

how w-ell

original power, as well as

provide a benchmark for later charge/recharge cycles.

battery pack to your computer.

The

files

if the

your race diary with subsequent races and/or batterydischarge tests so you have a recorded history of each

you can actually see how quickly the battery or battery pack will discharge under the load of the motor and radio gear.

immediately

program is a sure way to balance the output of your choice of motors to the batteries you have available. The West Mountain Radio CBA also battery analyzer

THE RACE DIARY Keep a race diary notebook to hold the set-up sheets that are described in Chapter 5 and record the details of every practice session or race, including race dura-

has an optional temperature sensor with an automatic

overheat cut-off that can minimize the danger to both

Above: Todd Hodge, Team

Lost's

team manager,

at the

2005

ROAR

is

checking the battery condition on his laptop

Off-Road Nationals.

89

tion

and your best lap times. Include a note on how battery life remained on each set of batteries you used after the race. With the experiences recorded in that notebook you will be able to make some good guesses for other cars. It can also be helpful when and if you decide you want to upgrade the model with a more efficient or more powerful motor and/or

most continuously

much

only to change battery packs. The smaller battery

a lighter battery pack.

pletely disassemble the car. If you are

for as long as

packs can recharge in as

little

as

you wish, stopping

20 minutes, and the

larger packs can take an hour.

Take wrenches to remove the wheels and any other nuts as well as an Allen wrench and a Phillips-headed screwdriver— every tool you would use at

home

to

com-

running nitro-pow-

ered cars, take a wrench for the glow plug, plenty of spare

THE TAKE-ALONG TOOLKIT when you head for the track you few Items

m

glow plugs, a starter and two batteries for the glow plug, fuel, and a fuel bottle. Take a roll of 1 1/2-inch-wide clear packing tape for quick body repairs and taping down a loose receiver. A wide selection of rubber bands is useful

want to take a and radio control

will

addition to the cars

The models should be checked over at home for any potential operating problems. You will undoubtedly need to make some repairs at the track, if only to recharge the batteries. Try to buy battery transmitter.

for

for

m-car receiver

in

nitro-powered cars, and a

car’s cigarette lighter so

Above

If

is

the

buy two or three extra

frequencies (in matched sets of

and RX

for the receiver) so

it

machinery gets

on and wipe away the

really

TX

muddy,

there's

RJC

racers.

dirt.

no substitute for a

stiff-bristle

brush

and a container of water and Simple Green. Opposite above: Up-ended food storage containers make great pedestals to support while you are making adjustments during the practice sessions.

the car

Opposite below: A portable light can be useful when you set up your pits at a track. The smaller ones provide plenty of power and fold up to fit inside a toolbox.

90

sets

with different

for the transmitter

you have a choice when you

get to the track.

a biodegradable cleaner that has found favor with

Just spray

Above right: When

your radio transmitter has plug-in frequency

crystal sets,

II

left: Simple Great

and alcohol-soaked hand wipes

can keep the messes to a minimum.

you can take the you buy a second set of battery packs, you can use them to replace the pack in the car or truck and the first pack can be charging while you race with the second. You can then race alplug into a

compoand diago-

battery packs or other loose

cleaner, paper towels,

charger for the transmitter batteries with adaptors to chargers with you to the track.

down

take a pair of small needlenose pliers

I

nal cutters with a few lengths of piano wire to replace any broken servo connectors. A bottle of all-purpose

chargers for the electric-powered car batteries, a charger

holding

nents.

91

BULLET-PROOFING YOUR RACE CAR All

of the ready-to-race and

as

reliable

as

kit cars are

Secure the servo motor with a

mass-production methods can make

motor you can afford from KO. A stock servo will transmit about 54 ounces and respond in 0.2 seconds, but the better servos will transmit 200 ounces and respond in 0.06 seconds. If the motor does not have a cooling fin

all

of the screws with socket-head screws

and apply a drop of stall

Loctite to each thread as

you

rein-

them. Pay particular attention to the motor-mount-

ing screws, the differential assembly and

cover, create one.

The concept of winning

mounting

a race includes the need to Keep your car clean so you can spot any loose parts or cracked joints. Check every nut, bolt, and screw for tightness between each race. Don’t forget to let off on

and the transmission screws because they are most prone to loosening from vibration. Check the steering servo motor and be sure it is fitted with either a screws,

spring or a white nylon clutch that will allow the slip if

one of the front wheels takes a

Above: One of the

arm

best servo

Airtronics, Futaba, or

severe crashes.

Replace

finish.

the throttle trigger

to

and apply the brakes

that first long straight.

hit.

best bulletproofing tips

socket (Allen-headed) screws. to

Buy

aluminum

if you

Buy the

them. You can certainly add a few personal touches to help ensure that your car finishes the race even after

some

billet

can find one to fit so the motor cannot flex to induce a vague response to steering inputs.

bracket

designed to be

is

to replace all

of the screws with hardened-head

a hardened-tip Allen wrench

and apply a drop of Loctite

each thread before you install the screw.

92

at the

end of

Above: Most

servo motors have so a

Below; To prevent install

some protective

jammed front

tire

devices like the white slip-ring clutch

won't tear up the servo motor.

the servo

motor from flexing

one of the billet-aluminum servo retainers

93

in the chassis,

like this

Team

Losi part.

7 CHAPTER

MORE ELECTRIC POWER & SPEED If

you have watched a radio control electric car race you will understand what more power can mean.

ou’ll see some of the cars rocket cars yards

behind by the

down the long

first corner.

performance of some of the 1/12

straight, leaving other

Or you may have been

able

compare the

scale toy radio control cars to a 1/10 scale

four-wheel-drive electric touring car to discover that the 1/10 scale racer

simply est

a

is

whole other world of acceleration and throttle response. Your quick-

thoughts, translated into movements of the radio transmitter’s steering

wheel or throttle/brake predictable

trigger,

movements with

are instantly translated

the car.

It’s

WHERE DOES THE POWER COME FROM? You would assume

that

all

that

the zip that a

comes from the motor

is

not the

the motors are there

is

case. In all

alone, but an organized race

limited by the rules so

out

usually not a lot of difference

between the motor

may

in

most thorough and careful preparaThe builder/driver has experimented with everything from gear rathe

tion.

a similar effect as does the choice of gear-

to suspension

ing.

Opposite: The modified to

lift

class

Again, the motor

is

the last

compo-

nent to change in any search for more

adjustments in order to determine, after comparing lap times with each change.

has atnple power

You

also have noticed that the chapter

on suspension precedes the chapters on general tune-up and this chapter on hopup. The reason is simple; the chassis has far more effect on the car’s performance than the motor. The selection of tires has

the quickest cars are the ones that have

compounds

in this chapter applies equally to ei-

ther electric- or nitro-powered cars.

one car and the motor in another. So why do some cars accelerate better than others? Because

tios to tire

that simple.

what work best for that particular car on that particular track on that particular day. All the extra power comes from the patience to test, alter, and retest again and again. The information on gearing and roll

real electric radio control racing car pro-

vides

into completely

performance.

of off-wad cars

the front wheels at nearly

95

like the

2WD buggy

any place on the

track.

GEARING FOR SPEED The motor

the range of about 4:1 at the motor, which

mechanical elements that transfers power to the pavement or dirt. In between are a small pinion gear on the motor and larger driven gear on the axle, an automatic clutch,

and there may be a third or fourth

perhaps a two- or three-speed transmission, some type of

sion. This

only the

is

first link in

differential at the rear,

the motor’s speed

the sequence of

and a second

trol cars there

is

that

tires.

On most

set at the transmis-

second reduction through the transmission

the owner’s manual.

and

you’ll find that

To obtain

number

gear ratio. Since the internal gear ratio (and the gear

but you certainly can change the gearing by changing

tios in the differentials) is fixed,

the pinion gear

on the

on the motor

that transfers the motor’s

where they contact the

The gear

ratio

is

shaft

and the driven gear

gear ratio, coupled with

axle. It’s that

power and speed

gears at the

at the

tio is usually

motor’s

tio

on

motor divided by the

number of number of gear

combination of speed and

and the highest The motor will not be able produce its maximum power or torque if you change the gear ratio by more than a few teeth at the pinion gear. Generally, the range for a 1/12 or 1/10 scale car is somewhere between 128/36 (3.56:1) and 128/25 (5.12:1).

Most

acceleration

2005 ROAR Off-Road Nationals with Mike Truhe (left) and Jesse Robbers programming the ESC speed control.

at the

rebuilding a shock absorber

maximum

practical top speed.

1/10 scale electric radio control cars have a gear ratio in

Above: Team Amezcua

faster if the gear ra-

been tested by the factory and a gear ratio has been

torque to give

larger spur gear; hence a car with a 32-tooth

(also expressed as 4.0:1) gear ratio.

might go

selected that will obtain the

ra-

pinion gear and a 128-tooth spur gear would have a

32/128 or 4/1

more or

were reduced so the car would travel farther for each

ever,

expressed as a fraction with a

gear teeth on the teeth

performance. Gear

ra-

refer to the

revolution of the motor. Your radio control car has, how-

of power and torque to get the car

maximum

most tuners

internal

as the gear ratio because those gears

Theoretically, the car

track.

tion or multiplier that increases the motor’s revolutions

moving

motor

motor by the

fewer teeth to alter the gear ratio.

to the tires

the term used to describe the frac-

to provide the balance

the gear ratio at the

are relatively easy to exchange for gears with

tire size,

is

in

the overall gear ratio you

ponents must be functioning smoothly. There’s not much you can alter in the transmission or differential(s),

must multiple

it

radio con-

a second set of gears in the differentials

called the internal ratio

com-

means

being multiplied by four before

reaches transmission and the

differential at the

front for four-wheel-drive. Obviously, each of those

is

96

ROLLOUT The gear

IS

WHAT

REALLY

MAKES

changes

ratio really only

will turn. It is the tire itself that

how

IT

determines

how

car will travel for each revolution of the motor.

tance

is

number

sometimes referred that indicates just

GO far the

That

to as rollout. This

how

Your

is

tial ratios. If

and the

one by the other to obtain the internal

about a 2:1 inAs an example, the Team Losi JRX-S has a 1.83:1 internal drive ratio. Taking that Team Losi car as an example (which appears in the manual and on the Team Losi website for the JRX-S), the car has 57 diameter tires and a 27-tooth pinion gear on the motor driving a 128-tooth spur gear so these are the numbers

ratio.

Typically, a 1/10 scale car will have

ternal drive ratio.

mm

or

tire/wheel combinations.

to lug-into the formula:

Rollout Formula Rollout

(s/p

X

=

(jt

X

d)

t)

where d =

differen-

only the two ratios are provided, multiply

the

each revolution of the motor. Does it matter? Only if you change tire sizes. So, yes, changing tire size also changes the effective overall gear ratio. There’s a complex formula (shown below), but you may find the rolltires

maintenance manual should provide the

dis-

far the car will travel for

out numbers lor different readily available

car’s

internal ratio and/or the transmission

fast the shafts

overall diameter of the tire in millimeters

_= 3.1416 s = number of teeth on the spur (larger or driven) gear p = number of teeth on the pinion gear (on the motor) t = the internal drive ratio of the transmission and differential

D = 57

mm

71=3.1416 S= 128 P = 27

T=

1.83

The math would be this: (3.1416 X 57 mm) = (179.07 mm) = (179.07 mm) (128/27 X 1.83) (4.74 x 1.83) (8.67) = 20.6 mm

97

1

you would produce if you lowered the gear ratio at the motor pinion and spur gear set from that 128/27 (4.74:1) to 128/28 (4.57:1) by replacing the 27-tooth pinion with a 28-tooth pinion. The math

is

not quite so

simple that one tooth on the pinion gear provides 2 travel,

but

it is

mm

close.

Alternatively,

you could

raise the gear ratio

by using

a 26-tooth pinion gear in place of the 27-tooth or 128/26 (4.92:1).

Plug that new gear ratio into the formula and

the car will travel only 19.9

mm

down

the track (com-

pared to the original 20.6 mm). Try a smaller

tire

with 55

mm diameter and plug that into the equation with original

27-tooth pinion and the car will travel

track 19.9.

down

the

mm for each motor revolution.

The farther the car travels down the track for each motor rev, the higher the gear ratio and the faster the

On

this particular car with this particular set

of

overall speed. Conversely, the shorter the distance the car

down

transmission and differential gears, pinion and spur

travels

gears, with these particular tires, the car will travel 20.6

lower the top speed.

mm down the track every time the motor makes a com-

Remember

Fitting larger tires, such as 59

would

travel even farther

mm, would mean

down

is

the

same

Above; The Team Associated RCI2L4 has a carbon axle

and sidewinder motor

Below: The so

best

unit,

performance

you can

set

it

be considerably larger.

effect

fiber chassis with fully adjustable front suspension,

and moveable four-cell

secret

is

tires.

to

The

roll-

out numbers for a 1/8 scale monster truck are going to

the

the track for 21.4

mm for every motor revolution, which

and the

that these examples are for a 1/10 scale

touring car with relatively small diameter

plete revolution.

car

the track, the higher the gear ratio

an adjustable

battery carriers to adjust weight distribution.

have the car fully prepared and ready when you leave home

on the track and be ready for the final fine-tuning that can win

98

races.

live rear

er lap times) to raise the gear ratio so the car rally

take advantage of the longer straight. Conversely,

can

on a

track with relatively short straights or a multitude of tight corners, the car

might be quicker with a higher gear

but provide more torque and perhaps better traction for quicker cornering, so the lack of overall top speed would be more than offset by faster speed through corners. It is usually much easier to change tires and wheels than to change gears. Check the rules you will be racing ratio to reduce its overall speed

under, however, because

yond the

smaller tires ally

some

will

not allow

tires be-

rules-specified range of tire sizes. Also, the

may

lower the chassis so

drags on the ground or raise

it

much

that

so that

it

it

actu-

does not

corner as quickly thanks to the higher center of gravity.

Most

racers stick with the stock tire diameter

MATCHING POWER TO POSSIBLE SPEED

changes

Simply increasing the potential overall top speed by raising the gear ratio will not always result in more actual

suit each track

speed because the motor

may not

long straight,

It,

it

hovt’ever,

the particular track has a very

Above: The

(in

suspension

terms of quick-

stock motors always have fixed timing

The modified motors can have adjustable timing, with the end

Below: A

typical stock

and make

the gears to

and may even change gears between heat and the main event if the track conditions have changed. In some ROAR racing classes, the motors and tires are actually handed out on the day of the race so the only things you can change are the gearing and the

have the power to pull

might be worthu’hile

The pros change

races

the car that quickly. There’s a better chance the car will

be even slower.

in the gearing.

and bell

motor has a pair of hairpin springs

the

end

bell

is

held by two bent-metal tabs.

held rigidly by the two Phillips-head assembly screws.

(left)

that provide tension on the

(on the woven-wire pigtails) with a simple armature (center)

99

set up.

and motor

motor brush

case (right).

The

local racers

would be

willing to share

some

in-

formation about what gear ratios work best at the local race tracks. If you are experimenting on your own, only change one tooth up or down at a time, such as a 27-tooth gear in place of a stock 26 or a 25-tooth in place of the 26. Have someone time your laps to see if the car rally is quicker with a change in gear ratio. Rethe temptation to

sist

make any

radical gear changes

because overloading the motor with too high a ratio

can burn

it

out as easily as over-rewing the motor with

too low a gear

ratio.

SLIPPER CLUTCH DRIVES It is

simple enough change the gears themselves, but

that’s only part

of the

task.

The motor must be moved

centrifugal clutch to allow the car to idle without

from the driven gear to maintain the correct gear mesh when you change either gear. The easiest way to get proper gear mesh is to squeeze a piece of closer or farther

cigarette paper or similarly thin tissue paper

ing.

down

A

lower-cost stock

is

Some

cars will also have

scribe

your

how

to adjust the slipper clutch if

car. Basically,

car will accelerate

ping for about 3 tires

Above right: A common

cause of poor performance

Position the wire so the

Below: the

If the

motor cannot provide

The worst-case scenario

is

motor brush can move

is

to

should be receiving

full

power.

modify the motor's timing.

a crimped-over stranded motor brush lead wire.

in or

out without binding on the motor

case.

commutator of the motor becomes pitted or wears in a concave shape, Larger shops usually offer a commutator truing service

maximum power.

that you’ll have to replaee

an armature

100

fitted to

from a standing start with clutch slipBy then the gear train, wheels, and

feet.

.

can he rotated

is

the clutch should be adjusted so the

motor ( top) can he replaced with a motor that has more power and speed

hell

two

car will de-

one

with adjiistahle brush timing ( bottom) The Phillips-head screws that retain the stranded copper brush lead wires

can he loosened so the end

mov-

essentially the equivalent to neutral in

when the car’s speed reaches a preset point. The manual that is supplied with the

between the

the

left:

clutch

or three forward speeds that are selected automatically

motor or spur gear support bearings to retain the gear mesh. Remove the paper and the gears should have just enough backlash so you can move the spur gear about 1/64-inch back and forth without it moving the pinion gear.

Above

The

a stick-shift transmission.

pinion and spur gear and push the two tightly together while you torque

nitro-powered radio control cars have a friction or

All

(or the entire motor) if the

at a low cost.

commutator

is

worn

too

far.

Some of the

larger cars

may also have a drive

Here’s what the ROAR rules have to say: “Only ROAR-approved electric motors, batteries, and bodies may be used in National Championship events. Motors, batteries, and bodies must have been listed in the Rev-Up newsletter, or on wu'w.roarracing.com 14 days prior to

unit be-

tween the motor and the gearbox or the drive gears to help dampen the response between the motor and the prevent excessive shock to the entire drivetrain.

tires to

In essence, these are

but they also help

shock absorbers for the

smooth out the power

drivetrain,

the event to be eligible for use.” Don’t let the 14 days worry you because most of the motors you’ll be consid-

delivery so the

tires get traction rather than wheel spin.

ering have been available for months,

HONEST ANSWERS FROM A DYNAMOMETER A

chassis

dynamometer

is

the tool that

check exhaust emissions in most

states.

then the engine speed rollers to

measure how

is

is

much power

and Gauges attached to the engine

is

deliv-

ering while other gauges can be connected to the engine

and exhaust to measure tuel, air, and exhaust flow. RC,’ Dyno Systems makes a dynamometer especially for 1/12 to

1/8 scale radio control cars.

namometer

to be sure

You can use

the dy-

m

that gearing, motor, or tire

power and at what speeds. The machine is $1,200, but you may find a dealer or a club that has a dynamometer and will rent out dyno time to help you tune your radio control race car using the same methods as the full-size race car shops. really are increasing

changes

HOW Some

FAST

WAS

motor components when the event requires that handout motors be used. Bushings may not be cut or modified in any type of handout motor.”

stock

THAT?

tracks offer the option of displaying your lap

MOTOR BRUSHES

times during practice, as well as during a race. Lap times are always a

own

more accurate measure of speed than your

If you are allowed to change the brushes in the motor, you will have a dozen different choices of motor brushes that range from hard to soft with an array of metal alloys and brush shapes. Generally, the really soft brushes will provide a bit more power but they can wear out in just a few races. It is most important that you replace any worn brushes before they wear to less than half their length to expose the encapsulated copper wires. It’s easy enough to snap out the brush springs and examine the brush. Always keep at least one spare pair for immediate use and

perceptions of speed.

The Nomadio and Spektrum brands of 2.4 MHz spectrum modulation (DSM) systems can be used

digital

in place

of frequency chips as described

in

Chapter

2.

These systems offer optional in-car telemetry systems to be used with their receiver modules.

The systems monimotor rpm, and

tor available battery voltage, display

monitor RF strength so you will know in advance if something is going wrong with car, the receiver, or the signal

from the transmitter. The devices also allow you and number of laps driven.

to serve as a guide to see

how much

MORE

ELECTRIC

MOTOR POWER

There are hundreds of choices of motors to

fit

would be wise

silver,

to replace the brushes with

new

it

ones.

These race car motors do get dirty, especially in an offroad car. The fan-effect of the spinning armature draws air and airborne dirt right into the motor where any

by the racing rules that are in effect at the tracks where you race. Your dealer can help you with that races in

discolored

MOTOR CLEANLINESS

fied

Most organized

is

perhaps more

blue, or faded white than the remainder of the brush,

the race

on these pages. You can buy a motor that is several times faster than the one that came with car. Before you do, however, consider how you will be using the car. If you are going to race it, you must use the motors speci-

ROAR rules,

the existing brushes

the brush has worn. If the brush

at the sides near the contact face,

cars

the

how much

have worn. The brush color can also be an indicator of

to record lap times

choice.

not years.

cific rules

started, put in gear,

increased.

if

a stock motor as having the same di-

mensions as the modified motors (below) and the spethat are being used for the race you intend to enter will specify whether the stock motors are limited to fixed-end bell motors that are not designed to be disassembled, to rebuildable stock motors that can be disassembled for adjustments or handout stock motors. ROAR racing classes include both on- and off-road categories for handout motors. You get the motor you are to use when you show up for the race. In some classes, you are also limited to handout tires. ROAR specifies, all stock electric class“Handout motors will be used es. The term “handout motor” includes the following components: cans, end bells, brush hoods, bushing, and armatures. All handout motors will be right hand drive only. Drivers may not use their own stock motors or

often used to

The dynamome-

accepts the rear wheels

ter is usually a set ol rollers that

of the car or truck. The vehicle

is

ROAR defines

America are governed by

light oil film will trap the dirt

but there are classes for both stock and

and grime. Unless the

racing rules specific that you cannot use a rebuildable

modified motors.

motor,

101

it’s

wise to buy a rebuildable motor.

You can

disassemble the rebuildable motors to remove the

maximum wire diameter (including insulaof 0.914mm, resulting in no less than 19 continuous turns of wire on each pole.” having a

ar-

mature and spacer washers by removing a few screws to tree the endbell. As you disassemble the motor, make notes about which washers or shims go where and how many of the washers are on each end of the armature. You’ll want to replace them just as they were. When you reassemble the motor, check to see that armature can only move in our 0.010 inches and add or remove washers to get that amount of endplay. Pull the endbell and the armature will be visible. If you like to tinker with things mechanical, remove the bearings and clean them m solvent. You can also flood them with WD-40 and

tion)

MODIFIED MOTORS The ROAR racing rules

are very specific about what modified motors are allowed in ROAR-sanctioned races.

motors may be used. For was set at $110 per motor. According to the ROAR Rules, “All motors must have the original manufacturer’s logo or name molded or etched into the end bell. (The) Can must have the original manufacturer’s logo, name, or mark. Overall maximum diameter: 3^.02mm measured at whatever point yields the

Only industry standard 05

2005, a

soak up the excess fluid with a paper towel. Repeat the process two or three times until the fluid you catch

draining from the bearings

an

air hose, a

is

perfectly clean.

can of compressed

air,

maximum

Then use

or your

own

maximum

size

retail price

dimension.

Maximum

mm

length: 53

meas-

ured from the mounting face of the motor to the

air

fur-

supply tank to blow out any remaining WD-40. There

thest

are special cleaning fluids for model racing cars that you might consider using m place of the WD-40. Use the same procedure to clean the motor case and the end bell and brush holders. The commutator will wear enough so that after about 20 races or an equivalent amount of practice time, you may want have the commutator face machined. Hobby dealers can usually do the machining for you or direct you to a club member or shop that can do

Motor mounting holes must be on 1-inch centers. Maximum Armature stack length: 22.6 mm. Maximum Armature stack diameter: 23.2 mm. Only three pole armatures are permitted. Only ceramic magnets are permitted. Cobalt and rare earth magnets are specifically prohibited.” ROAR has some specific rules for the modified oval classes with 19T motors: “19T modified oval motors may be based on any ROAR-approved modified motor combination (can, endbell and armature). Suggested retail price for a complete motor shall not exceed $65. Sug-

REBUILDABLE SUPER STOCK

MOTORS

gested

up the ladder from out-of-the-box stock to all-out modified are cars that race with motors that are rebuildable under the ROAR Super Stock classes. The motors are usually referred to as 19T models. The ROAR rules state, in part, that, “Motors in this (Super Stock) class are intended for on-road and off-road racing, not for oval racing. Oval racing I9T motors are described under the Modified Motor section of these rules. Motors submitted for approval as rebuildable 19T Super Stock motors must have the manufacturer’s name m the form of XXXX 19 (e.g., EPIC 19, YOK 19, etc.) permanently stamped into the mounting face of the motor can. XXXX 19 designates the use of the can for 19T Super Stock class racing. The manufacturer name on the can will make hybrid motors easy to identify. Rebuildable 19T Super Stock motor armatures must be machine-wound using a crosswrap technique. The legal 19T Super Stock wind is a minimum of 1,170 mm of round 19 American Wire Gauge (AWG) wire.

A

shall

2005

not including solder

retail price

an armature

shall

not exceed $30.

of a can and endbell combination

not exceed $30.”

PICKING A MODIFIED

MOTOR

The motor’s armature is wound with a number of insulated copper wires. The smaller the size of those wires, the more turns can be wrapped around each pole of the armature; the larger the wire, the fewer the turns that can be wrapped around each pole. Generally, the larger the wire, the faster the motor,

but that can be compromised

by running two smaller wires side-by-side

in

groups of

two, three, or even six or seven, so wire size alone

ways the determining

factor.

is

There are dozens of

not

al-

differ-

ent combinations of wire size and patterns in wrapping the wire. For simplicity we’ll

wire size

is

used to

wrap each

pared to the camshaft (or to the

assume that just a single Wire size can be com-

pole.

m a four-stroke automobile engine

expansion chamber in a two-stroke motorcycle

or radio control race car engine). If you

1/ 1 2 scale four-wheel-drive tuodified

at the

retail price for

Suggested

step

Opposite:

bell,

tabs or lead wires. Shaft diameter: 0.125 inches.

the machining.

The next

most point of the end

ROAR

buggy scratching the

Off-Road Nationals.

102

air for sixth place overall

want pure

To sum up

the chart you

cop-end power, you go for a hotter camshaft or with an

the quickest possible lap times.

motor with smaller-gauge wire and fewer turns. If you want low-end torque, pick a motor with smaller wire and more turns per pole. The chart here will get you in the ballpark when picking a motor for a specific racing class. The chart only lists single-turn wire sizes. Your dealer can help you pick the double-turn or multiple-turn equivalents or suggest some more exotic wire-winding patterns that work especially well in particular cars on

FEWER TURNS produces more top-end power but faster battery drain and MORE TURNS produces more acceleration

particular tracks for particular racing classes.

armature to deliver

can consider the number of turns per pole thus:

electric

but slower battery drain.

BRUSHLESS MOTORS Most

ture)

is

tating armature.

in

models of all types have a

electric current the wires

Those wires

and when rotating

always going to be a compromise. With years of

you may be able

motors used

pair of sintered-metal brushes that touch the rotating

Picking a different armature (or motor with arma-

on the

ro-

act as an electromagnet,

inside the fixed magnets, they force armature to rotate. A brushless motor also has an the electrical current is delivered across armature but the motors are faster and lighter an air gap. The brushless more expensive. brushed motors but are also than motors. brushless has an approved list of ROAR also

motor and armature, as well as tire type, tire size, gear ratio, and suspension set-up that will work best on a particular track on a particular day with a particular car. For most of us, it’s a matter of trial and retrial to see what produces

experience,

electric

to find a particular

103

RACING CLASS, WIRE TURNS

ON MOTOR ARMATURE 10

9

8

7

yes

yes

no

no

no

yes

yes

yes

no

no

no

no

no

no

no

no

no

no

yes

yes

yes

no

no

no

no

no

yes

yes

yes

yes

no

no

no

no

no

no

no

yes

yes

yes

yes

no

no

no

no

no

no

no

no

no

yes

yes

yes

no

no

no

l/IO stadium truck

no

no

no

yes

yes

yes

no

no

no

no

no

Drag racing

no

no

no

no

no

no

yes

yes

yes

yes

yes

Truck

no

no

no

no

no

yes

yes

yes

yes

yes

no

17

16

15

14

13

12

l/IO on-road

no

no

no

no

yes

yes

l/IO oval

no

no

yes

yes

yes

1/12 on-road

yes

yes

yes

yes

1/12 oval

no

no

yes

1/12 carpet

no

no

l/IO off-road,

no

1

1

2-wheel-drive l/IO off-road.

4-wheel-drive

The

pulls

ROAR

motor as, “Senallowed. The motor has

those designed for sustain high rpm.

rules define a brushless

sored or sensorless motors are

to be rebuildable. Ball bearings are allowed.

A

ly

Most have

relative-

low current draw.

mini-

mum

ELECTRONIC SPEED CONTROLS

must have been sold or hobby shops or OEM’s

The ESC is the electronic device that transmits the commands from the radio transmitter into signals for the motor to speed up or slow down. The trigger on the transmitter provides the input and there are usually

of 2,000 brushless motors must be available at the time of approval. A minimum of 300 brushless motors

maximum

retail price

to at least three distributors at the time

of submittal. The

of a modified brushless motor

shall be $ 129.”

COMM OR

you can get the car to respond at you can best control. Obviously, there’s no

vernier adjustments so

a rate that

BIG

(ESC)

SMALL

COMM?

In radio control racing language,

“comm”

more is

actual speed, just quicker or slower response to

on the trigger. The more powerful motors

short for

pulling

commutator. The commutator is that portion of the motor’s revolving armature where the motor brushes ride to provide the power to spin the armature inside the motor’s magnets. Some racing motors are divided into “big comm” and “small comm” categories. The big comm motors are desired for high load and high current needs that are found in serious off-road racing. The big comm motors may run cooler because there is more copper to dissipate the heat, and there can be slightly less electrical resistance. The small comm motors are usually

requirements. Also,

ESC designed

ESC

(those with fewer turns)

match their power flow the brushless motors should have an

often require a specific

to

for the specific

performance characteris-

Check with your dealer or the motor or ESC maker to match the motor to the proper ESC. You will also have to decide whether you want the ESC to have the capability of providing a reverse gear and pick one that provides that function if you feel you need it. The competition ESCs do not usually have reverse. tics.

104

TROUBLESHOOTING ELECTRIC MOTORS

EASY-ENTRY INDOOR RACING

The quickest way to check for trouble with a motor is to replace the motor with another. If the problem persists, then the fault does not lie in the motor. If a new motor

The 1/10 and 1/12 scale indoor carpet racing classes are some of the easiest to learn to drive, in part because you can race all year long. The cars themselves are less complex so you don’t need to worry about setting up differ-

cures the problem, the fault

lies

with the original motor.

You can often save a lot of time searching for a flaw if you can borrow another transmitter to determine if the problem

lies

with the transmitter rather than the

entials or rear-wheel steering or a host

racing.

car.

the

most common fault first, but that is only The fault could be any on the list, as well

scale electric-powered radio

of surface. There are some clubs and hobby shops that

just the as

The 1/12 and 1/10

control cars can be raced indoors on virtually any type

These troubleshooting tips are arranged in the order of odds.

of other set-up

options that can plague a newcomer to radio control

some

offer indoor race tracks that are

paved with indoor-outdoor

carpet. Races are usually scheduled for all classes of on-

other faults.

Above: Most two-wheel-drivc

mount

the

motor parallel

to the

cars, like this

back axle sidewinder

Team Associated Factory Team RC12L4 style

oval

pan

car.

with the pitiion gear on the motor shaft and the spur gear

(which contains the ball bearing differential) on the axle shaft but no transmission, clutch, or gear cover.

105

road

cars.

One of the more popular carpet

race classes

Team

Associated Fac-

the slightly

more complex

1/12 and 1/10 scale cars like the tory

Team RC12L4 and

RC10L4. The motor

is

mounted

parallel to the

shock absorber provides the rear suspension

coil-over

is

the oval pan class for relatively simple two-wheel-drive

control with a conventional two-shock independent Iront suspension. like the

Team

The more expensive 1/12

chassis with fully adjustable front suspension, an ad-

back axle

sidewinder style with the pinion gear on the motor shaft

justable live rear axles

and the spur gear on the

moveable

clutch, or gear cover.

axle shaft but

The

no transmission,

entire motor/axle unit

is

and sidewinder motor

four-cell battery carriers to adjust

tribution.

piv-

oted on a ball joint with control links. Usually a single

TROUBLESHOOTING ELECTRIC MOTORS SYMPTOM

POSSIBLE CAUSE

Motor runs slower and slower

Discharged or weak batteries

wedged around gears

Dirt

Dirt or string lodged between wheels

Gears meshed too closely together Dirt on the motor’s

Motor brushes not

commutator

free to

move

Worn-out motor brushes Faulty

ESC

Wires from

Motor runs

batteries to

motor too

small

Discharged or weak batteries

erratically

Motor brushes not

free to

move

Worn-out motor brushes Dirt on the motor’s Faulty

commutator

ESC

Faulty battery pack

Loose wire connections Transmitter trigger functioning improperly

Motor

is

scale cars,

Associated RC12L4, have carbon fiber

excessively hot

wedged around gears

Dirt

Dirt or string lodged between wheels

Gears meshed too closely together

Car runs Gear

106

for too long at

ratio

too high so

full

throttle

motor

is

lugging

units,

and

weight

dis-

THE TEAM ASSOCIATED RC12L4

Servo saver

Motor

Receiver

Foam

Tie rod

Above: The Team Associated RC12L4 to the sidewinder-style

At the rear

is

is

a 1/12 scale on-road

pan

motor on a rear subframe with a

car with the rear axle running parallel

single coil-over shock absorber.

a conventional independent front suspension with two coil-over shock absorbers.

107

tires

4 O' I

8 CHAPTER

NITRO RACE CAR PREPARATION With

the exception of the engine

and

the servo

motor that operates the carburetor, 0 nitro-powered radio control race cor is virtually identical to a similar size

and

class electric-powerecl car.

O FIND OUT MORE ABOUT THE RADIO SYSTEM AND THE CHASSIS AND SUSPENSION preparation, please refer to the previous chapters.

The

chassis set-up tips in

Chapter 5 are intended for both on- and off-road nitro and electric-powered cars, as is the tire-selection

information and bullet-proofing tips in Chapter

6.

STARTING THE ULTIMATE MINIATURE RACING MACHINE

the exhaust pipe exit.

The nitro-powered cars are considered to be the most sophisticated radio control cars because they most resemble a real car. It’s the engine that is the most noticeable

measure the length of what the maximum length of pull is available. I would suggest you limit the length of each pull on the starter cable to be between 6 and 12 inches, assuming the cable is 12

start

up a nitro-powered

a miniature racer because smells like one. But

it

car that

available cable to see

it is

sounds and

you have

not connect

pull-starter,

resemblance. There’s no question once

you

Do

the battery glow plug. If you are using a

inches or longer.

it

Pull the starter cable three or four

been sitting for long,

times with the throttle trigger on the

moment and remove the glow plug. Hook up a D-cell battery or Ni-Charger

ond. Attach the battery to the glow plug

and

and

first

started. If the car has

to get

transmitter held open for just a half-sec-

take a

see if the plug glows a bright orange.

give the starter cable several of those

12-inch quick pulls.

The engine

If so, replace the plug.

6-

Prime the carburetor by pulling on the starter while you hold a finger over

should start and you can remove the bat-

Opposite: These 1/10

to

tery

scale nitro

connection from the glow plug.

stadium trucks are competing

on the banks and jumps at Rat Raceway

109

in

Denver, Colorado.

PUSH-BUTTON STARTING

car so the bearings

Some of

but worn smooth. There are at

the nitro engines are designed to accept an

break

STARTER BOXES race tracks will have rectangular boxes with a

motor

It

and a spinning rubber wheel. To start your car, start the motor in the starter box and gently lower the car over the box until the rear tires touch the spinning wheel. The model car’s large electric

so

Remove

moment

BREAKING It is

IN

A NITRO ENGINE in the

idle

with the rear wheels spinning. Let

it

idle until at

tanks of fuel have been used, then run two

a local full-size car speed equipment shop. The tape you need should register in about 10-degree increments from 150 to 250 degrees Fahrenheit. The tape changes color at the maximum temperature, but it is

fires.

important to break

to

fuel with the engine running at less than one-quarter throttle. If you expect to get maximum power from the engine without destroying it, you will need to buy something to record engine temperature. Your dealer can locate temperature-sensitive tape or you can find it at

the car from the starter box the

the engine

ways

more tanks of

the engine should start within a few

throttle

least a half-dozen

a

least three

inside

rotating tires will turn the engine over at about half

seconds.

sliding surfaces are not scuffed,

model race car engine. Here’s the procedure that Chadd Brockman at Mohr Raceway uses. Never ever, no matter what, run the engine indoors. The break-in process is going to take time but stick with the car. This might be a good time to read the manual that came with car. Support the car on the edge of the table with the rear tires off the ground and use an old belt or tiedown strap to secure it so there’s no possible way to accidentally work its way loose. Start the engine and let

you do not have use the pull-starter. These push-button starters have their own electric motors powered by rechargeable batteries. The engine must be designed to accept the drive tabs on the starter so you may need to match the brand of engine with same brand of starter. The engine manufacturers sometimes offer retrofit kits to replace the pull-starter with a drive unit to accept a push-button starter. electric starter so

The

m

and

engine of your model race

no

usually only

ing

if

good

for

one run.

way of determinR/C version car’s tachometer). Or

It is

a

the engine has been overloaded (an

of the redline on a full-size race

you can buy a temperature gauge like the type sold by HPI Racing and Venom Racing so you can monitor the engine as you break it in. The temperature gauge will also be useful when you begin to tune the engine to try to get more power because engine temperature is the best indicator that you have gone too far with any tune-up tricks. Connect the temperature gauge’s heat sensor about 1/4-inch avv’ay from the glow plug. A stock engine should run at a maximum of about 200 to

280 degrees.

Opposite; The

coil

spring to the

The small blue

from

collar

left

prevents the throttle servo from breaking either the carburetor or servo arm.

can be moved in or out

to

provide more or

less

tension to prevent

affecting the carburetor’s response to the driver’s throttle

Above; Most engines

require

an additional

electrical

glow plug

bumps

commands.

igniter

(

not shown)

or a D-cell battery to provide the current to force the plug to glow.

Below; The gear either of these

The

ratio

two

on a four-wheel-drive nitro-powered car can be changed by replacing

gears, the pinion gear

on the motor, or the spur gear on the transmission.

larger spur gear should turn freely if the centrifugal clutch inside the transmission

Ill

is

operating correctly.

laps or so

and

reset the

gine temperature

high-end needle. Check the en-

when you bring

the car in for the nee-

dle adjustment.

you can drive but and check the engine temperature every

Finally, race the car as fast as

bring

it

into pits

10 laps or

so.

ENGINE SEIZURES it to develop all the powwas designed to produce. Breaking the engine in will also minimize the chances that it will get so hot that pis-

Breaking in the engine will allow

er

it

ton

will seize in the cylinder bore. If the

do not

try to

crank

it

over. Let

it

engine does

cool completely.

seize,

You may

be able to get a look at the piston by removing the ex-

Now you can

take the car to track

and run

it,

gently

any sign of damage, pull the

haust manifold.

If there

cylinder to see

the piston or cylinder are scored beyond

if

Your dealer

is

accelerating to full throttle, then backing off until

you

repair.

During

this

ton and cylinder can be used or

have run through another 6 tanks of

fuel.

end needle so the engine reaches maximum rpm, then run the car around the track. Bring the car in every 10

trick to easier starting

is

to use

with your wrist rather than

Below: To

be able to determine if

if

a

new

pis-

the crankshaft or big

end bearings have also been overheated and damaged. In some cases it is less expensive to buy a new crankshaft, rod, piston, and cylinder than an entire engine.

period pull the car into the pit lane and adjust the high-

Above: The

will

a quick pull of less than 12 inches

full

forearm action.

turn off the engine, plug the exhaust with a rag over your fingertip

112

ami pinch

the fuel line to the carburetor.

Above

left: Hold the glow plug against the cylinder head with a D-cell battery or igniter

connected

to the

glow plug’s outer

a few times to see

Above right: Below:

if the

tip,

and pull

Use a T-handle wrench

to

remove the glow plug from the cylinder head.

If the starter pul! does not turn the engine,

one-way mechanism

inside the

the crank handle

plug glows a bright yellow as shown.

end nut (shown)

113

is

remove the unit and be sure that the

engaging. If not, replace the mechanism.

NITRO FUEL not use fuel intended

your dealer and the local racers to see which fuel works best in your area. Again, be sure that fuel you are using is legal for any racing classes you may want

model airplanes because their engines operate under a completely different environment. The oil

contain only methanol, nitro methane, coloring

that lubricates the engine in your nitro-powered car

agent,

>% as

Your dealer can supply

fuel chat

for radio control race cars.

Do

is

especially blended

for

aik

is

of

mixed with the oil is

m

may

a lubricant.”

of the 1/5 scale cars, like the HPl-Racing Baja 5B, have small lawnmower-style industrial engines that

SYMPTOM will

and

rules stipulate that, “Fuels

Some

For a race car the percentage the range of 8 to 12 percent. Check with fuel.

Engine

ROAR

The

to enter.

POSSIBLE CAUSE

not start

Faulty starter battery

No

fuel

Clogged

or crimped fuel line

Clogged

or blocked fuel tank vent hole

Loose plug Carburetor adjusted improperly

Not enough

Runs too hot

air

flow through body vents

Dirt

wedged around

gears

Dirt

or string lodged

between wheels

Gears meshed too

Car

closely together

run for too long at

Gear

ratio

Dirty air

full

throttle

too high so motor

is

lugging

filter

Carburetor set to lean

Carburetor leaking

air

Cracked crankcase

Wrong

fuel (with

too

little oil)

Loose glow plug

Engine runs erratically

Loose cylinder head

Blocked

fuel

Crimped

Won't increase speed

vent

in

tank

or blocked fuel line

Worn engine

bearings

Foam

oiled

air

Fuel line

Defective

filter

and clogged

crimped or blocked

glow plug

Improper carburetor settings Air leak at carburetor

Glow

plug loose

Cylinder head loose

114

are designed to run cycle gasoline

and

on conventional two-stroke motor-

oil

mixtures.

TROUBLESHOOTING NITRO ENGINES The quickest way to check is

for trouble with a nitro engine

to try to operate the throttle

carburetor.

That

will at least

by hand at the link to the

eliminate the servo, linkage,

and any radio or transmitter problems from your checklist. They are arranged in the order of the most common fault first, but that is only just the odds. The fault could be any on the list, as well as some other fault.

Above: Most

tracks offer electric starter boxes that drive the rear wheels to start the engines in nitro cars.

Below: Turn

the engine over by

hand

to

be sure the piston

is

moving freely.

You can inspect the exhaust side of the piston by removing the exhaust manifold.

115

Above.

1 his

Team Associated

nitre TC3 factory team 1/10 scale touring car chassis has most of the performance parts already in place.

Below: The dark nitro

7C3

black chassis

1/ 10 scale

is

a hardened

aluminum

factory

four-wheel-drive touring cars from

116

team accessory for the

Team

Associated.

Above; The Team Associated

Below: Tamiya's

nitro

quickest 1/10 scale touring car chassis

TC3 team is

117

fitted

car has a side exhaust.

with most of the hop-up parts at the factory.

9 CHAPTER

MORE NITRO POWER & SPEED much speed

There's no such thing as too

especially for

R/C

someone whose passion

cars.

If

is

a racer,

to

racing nitro-power

sheer straight-line rocket-propufsion cars

are your choice, then you nave probably already bought a

1/8

scale nitro car, and even those can be

made

quicker.

RACK SPEED There are very few groups around the world that use radio control cars for

drag racing. For most racers, radio control racing means running around

a road course or an oval with one or two long straights. Probably 90 percent

of the time around any given road course ship acceleration

down

the straight

is

may

speed that wins races. The information

in

spent in the corners. That rocket be impressive, but

Chapter

5 will help

it’s

cornering

you get any on-

or off-road car to corner quicker. Get the handling tuned to perfection learn to drive well

win

races.

enough

to take

More power comes

advantage of that handling and you

and will

next.

GETTING THE POWER TO THE TRACK

Certainly the tires themselves play a role

you started searching for the bestperforming tires, on- or olf-road, in Chapter 6. The engine’s performance is delivered to the track through at least one set of gears and those gears can be changed to optimize the car’s performance. The information you will need to

and

select the

The goal of setting up

a race car chassis

is

power to the track and to corner, brake, and accelerate with the least possible amount of wheel slip. really to get the

there’s

enough information

to get

proper gear ratio for your car

Opposite; There arc hundreds of radio control race car tracks around the country, both paved and indoors and out. This is the RC Madness outdoor off-road track in Enfield, Connecticut.

119

dirt,

is

7. You may also want consider replacing the on the 1/8 scale cars with an adjustable clutch like the CRF V6 from Team Orion. The shift points for the

in

Chapter

engine.

clutch

two-speed transmission can be adjusted more accurately use an electronic engine diagnostic device like the

Magma International APS

most

motocross automobiles have used two-stroke engines since the Saabs of the 1950s. The basic principle of

hausted out the

MORE ENGINE POWER

Above: I/IO scale

I/W scale

nitro touring cars are generally the quickest class in

nitro touring cars

is

tailpipe.

Again, those pesky racing rules will limit what you can and cannot do with your engine, so read them over

we can consider getting more power from your

Here, a field of

No

getting more power is to find a way to get more of the correct fuel/air mixture to flow through the engine and to be burned as completely as possible before it is ex-

typical

two-speed for oft-road stadium trucks, monster trucks, and truggy racers.

Finally,

is

identical to the two-stroke engines in

motorcycles.

Nitro EDS. HPI Racing offers

more

the attractions of nitro-powered cars

m

if you

a three-speed transmission, as well as the

One of

that they have engines that operate like those real racing machines. The engine in your radio control car is al-

lined up for the start at

120

on-road

Mohr Raceway

R/C

racing.

in Denver, Colorado.

power parts

before you start searching tor if the

changes you want to make

will be

that are as large as can be fitted inside the castings. If

to determine

you

allowed in an or-

ganized race.

you will undoubtedly chip the and a new cylinder will be needed. You

try increase the size

cylinder lining

can, however, be absolutely certain that the gaskets be-

BREATHING SPACE It

you can get more

tween the exhaust manifold and the cylinder exactly

air into the

match both the cylinder and the manifold.

engine you can adjust the

carburetor to provide a matching

amount of

not even consider running without an

fuel.

air filter

Do

unless

there

you are willing to replace the worn-out engine every few

hundred

laps.

Larger and freer-flow’ing air

however, be available for your facturer claims

its filter

slightly larger filter

dealer

and the

flows

car.

Every air

filters filter

in

your

area.

method of getting more power into an it: Enlarge the intake and exhaust ports more fuel/air can get in and out. Don’t even think

so

is

to port

about that with a radio control engine. All of the twostroke engines have intake, exhaust, and transfer ports

Above: Pure power

is

not enough ( see

if the tires

if

into the

away.

POLISHED PORTS

traditional

engine

it

amount of gasket hanging

Another traditional method of finding more power is to polish the intake, exhaust, and transfer ports. One theory is that the smoother the walls of the port, the faster the flow of fuel/air mixture. There have been some studies that suggest that a slightly rough surface may produce a boundary layer that actually allows the fuel/air to move faster in a slightly rough port, but neither case is conclusive. Just understand that there is always the chance that you could actually lose power by polishing the ports. Use fine polishing paste and a buffing wheel

a

PORTING FOR POWER The

the slightest

may,

manu-

more than any other but

what works

is

port, trim

can often be a help. Again, ask your

local racers

Test-fit the

gasket on the cylinder, then on the manifold, and

do not hook up with the

Chapter 5) before going

121

all

dirt so get the suspension adjusted perfectly

out for more power.

on a Dremel

tool to polish the intake, exhaust,

transfer ports until they

cylinder bore by covering

gleam

it

and

that will allow your engine to keep producing power

longer than

like silver. Protect the

ment

with masking tape, but be ex-

tremely careful that the polishing wheel does not touch the inside of the cylinder or the gasket faces.

tios,

When you

it

would with the stock head. Some

but the primary benefit

To

find noticeably

entire engine.

three times with engine cleaner, blowing

gines 0.18TZ, the

dry with air

swab out

work

it

into every corner of the cylinder to

particles that

might

still

increased cooling.

OFNA

replace the

engines, like the O.

S.

En-

0.27, or the Traxxas 2.5, are

available for most nitro-powered cars. For super power, you might consider adding a Nitrous Express system to

pressure. Just to be sure, dip a pipe cleaner in engine

cleaner and

is

more power, you can

More powerful

are satisfied with the shine, clean the engine at least it

replace-

cylinder heads also provide higher compression ra-

inject nitrous gas into the carburetor just like the full-

be stuck in a scratch

or groove.

and drag

size drift cars

racers.

The nitrous charge

is

turned on or off with the radio transmitter’s third chan-

BOLT-ON POWER The quickest path head. The racing

to

nel

more power

is

to

buy

a

new

you intend to

cylinder heads provide better cooling

Above: To

successfully complete a

and a servo

in the car. Again,

to see if the engine

cylinder

mulconierjump, the

chassis

is

legal for the class

enter.

alignment and power delivery must be smooth

enough so the driver can almost feel the flow of power through the transmitter

122

check with racing rules

you want to use

trigger.

\mm

Above: The

first

maximizing performance

step in

This

is

Beu3w: This Dodge

is

to

keep the car clean so you can see and correct any flaws.

Russ Horton’s 1/10 scale nitro touring car on the tuning stand.

Stratos, a 1/10 scale nitro touring car,

thanks

in

part

to

plenty of power

is

sliding smoothly in a four-wheel drift

and perfect

123

throttle response.

MORE CARBURETOR Replacement carburetors are available

for

some

performance and enough muffler worth installing.

en-

five

nitro classes:

The chart below

lists

the

ROAR class

by engine displacement in cubic inches

placement size

m

in cubic centimeters (cc),

millimeters

first,

(ci),

practical to

shown

fit

followed

feet; 3 feet

mum

engine dis-

and carburetor bore

(mm).You may be

it is

above the ground, with the vehicle at maxi-

throttle

and

at all speeds.

A

Radio Shack sound

meter (Part #33-2055) or equivalent should be used to check the sound level.”

able find a larger

carburetor than these for your engine, but

make them

The ROAR rules indicate how the sound should be measured and the maximum level that is allowed in a ROAR-sanctioned event: “The maximum allowable sound level is 85 decibels, measured at 90 degrees to the direction of travel of the vehicle from a distance of 33

some cases a large carburetor can produce more power, especially if it is matched to a freer-flowing exhaust system. The ROAR racing rules limit cargines. In

buretor bore size by engine displacement in the

effect to

You are not likely to buy your own sound meter, but you can get a very good idea of how loud is too loud by attendingxjne of these races. If you are racing in a ROAR-

seldom

anything larger than carburetor bore sizes

here.

sanctioned event, your choice of exhaust system

EXPANSION CHAMBER POWER

limited to those specifically approved by

One of the

fables about speed is that a louder engine produces more power than a quiet engine. That’s a difficult one to refute because noise really does “feel” like more power, but is usually not true. Most of the

does, however, give

ready-to-run and kit cars are fitted with an exhaust

ONE

system that includes

The

at least

some type of

basic principles behind the expansion

of potentially more powerful exhaust systems for most nitro-powered

chamber

its

Chapter 8. Replacement exhaust systems from a number of firms that provide both more

time the laps again.

0.12 Open Class: 0.129

ci

0.15 Open Class: 0.152

ci

Open

0.214

ci

0.28 Open Class: 0.284

ci

Class:

laps so

ci

to 2.1

1

cc 5.5

mm to 2.5 cc 7.0 mm to 3.5 cc 9.0 mm to 4.66 cc 9.0 mm to 2.1

124

1

cc 5.5

feel

you have a

necessary and

What you “feel” with transmitter is not

CLASSES:

0.12 ROAR/IFMAR Class: 0.129

0.21

and then time the

benchmark. Make whatever change you

able

improve

performance, make one change at time. Try the stock

car for a few laps

are avail-

ROAR NITRO

cars.

STEP AT A TIME when you are preparing your radio control car to

muffler.

exhaust systems on two-stroke engines are described in

you a reasonable

will be

ROAR. That number of choices

mm

Above: This RDLogics

1/H scale

Below: Aftermarket

SHO

buggy

is

fitted with a

air filters, like this

foam

CVEC AF0421

125

air cleaner

unit,

and an expansion chamber with a

can increase airflow

to

side exhaust.

provide more power.

always more speed.

The

producing more noise.

car

may simply be

When you

sliding

more or

times you see are those from the actual race. With in-car telemetry you can record lap times on your

are finished with a tun-

know from your lap times whether the than it was when you started testing.

own

ing session you will

practice track to determine if the changes

car

made make

is

faster

in the chassis, tires, or

motor

rally are

the car quicker.

HOW FAST WAS THAT? running the Nomadio or Spektrum 2.4 MHz spectrum modulation (DSM) system m place of frequency chips in your transmitter and receiver as described in Chapter 2, you can purchase an in-car telemetry system. The system has a handheld screen like a small video screen to relay information from the car. The system monitors engine temperature and battery voltage, displays engine rpm, and monitors RF strength so you will know in advance if something is going wrong with car, the receiver, or the signal from the transmitter. Perhaps the most interesting aspect of the device is that it also allows you to record lap times and number of laps driven. Some tracks will provide a display board with your lap times, but usually the only lap If

you

are

digital

Above: This Mugeii

MTX3

is

fitted

Below: Aftermarket exhaust systems,

with a

CVF.C

like these

air filter aiul a

CVEC units,

126

CVF.C dual chamber exhaust

are designed for specific chassis

and

system.

engines.

private

you have helping to

Above:

CVEC offers a

series

of exhaust systems that have variable dual chambers that are tuned

on a dynamometer

Below: The cones

inside the to

to

produce more torque and power.

CVEC power system

exhausts are shaped

provide better exhaust flow for each engine.

127

and tuned

at the factory

128

&

Above: This Team Flextek

RC milled titanium

end plate, radio box

Losi 1/10 scale

cover,

and pin-retainer

than stock hut the

Opposite above: This including a

iiitro

1ST Monster

cover.

aluminum

parts are primarily for show.

the

Team Associated Nitro TC3+

new

cylinder head, muffler, chassis,

is

truck has been fitted with

and bumpers, and a milled ahmnnmn gear cover, The titanium arms should be stronger and lighter

suspension arms, skid plates

Opposite below: This hardened aluminum available for the

chassis

Team Associated 1/10

chassis refitted with all of the factory racer parts

and carbon

is

fiber suspension parts.

one of the dozens of factory team parts

scale nitro touring car

129

TO+ chassis.

10

CHAPTER

ON

DRIVING THE DIRT

Doing 0 double, power-sliding with a sky-high rooster toil of damaged dirt. Backing into a corner. All the

such a to

make

things that thrill

to

real off-road racing

watch are available

recreate using that transmitter

in

you your hands. for

EALLY THE ONLY DIFFERENCE BETWEEN RACING A FULL-SIZE CAR

doing the same with a 1/10, level.

Back

flips that

ON THE DIRT AND

1/8, or 1/5 scale radio control car

would reduce

a real car to a pile of

the injury

is

jumbled rollcage

tubes and send a driver to an ambulance seldom faze these off-road race cars.

The majority of radio control

DRIVING OUT OF YOUR MIND

car racers

learn to drive with an off-road car.

The

There

really

is

only one way to learn to drive

techniques for driving both on- and off-

a radio control car and that

road are similar, and learning to do

dozens, even hundreds of hours until you

it

in

the dirt can be extremely helpful for

learning to control a drift

on the

is

to drive

controls.

ment. Conversely, the faster speeds the

on pavement can make you aware that you may be able to drive just a bit faster than you thought you could in the dirt. Consider this chapter and Chapter 11 to be a pair and apply the lessons from both chapters that suit your cars and skills.

will

unconsciously respond. You

how the

track

is

going to

affect

your car.

Opposite: The broad, sweeping curves are the most spectacular one at

literally

movements around the track. Like a musician, you must practice long enough so you can completely forget what your hands and fingers are doing and concentrate on the track itself and

“think” the car’s or truck’s

hut they're some of the easiest portions of the course, particularly like this

for

no longer have to think about using the With practice, your mind will suggest turning slightly left and your fingers

pave-

cars can achieve

onto the straight

it

RC Madness

131

if

they empty out

track in Enfield, Connecticut.

VIRTUAL OFF-ROAD RACING

Experienced drivers spend most of the race looking a

few

feet

ahead of the

car,

anticipating what needs to

If you find it difficult to learn to drive a radio control car on a track, you might consider using one the virtual radio control programs as a learning aid. These programs can also be helpful for times when you cannot get to the track. You can also use your transmitter to drive “virtual” offroad cars using the DuraTrax (http://www.realrace.com/) Internet simulator. There are additional programs for onroad cars in Chapter 1 1 that you might try to improve

be done by “reading” the track conditions. For example,

jump coming and without any conscious thought whatsoever, their fingers react to get the car pointed straight at the jump with the throttle set precisely right to carry the car over the jump. While the calls in midair, their thoughts are the landing site, not on they see a

the car itself

The

car

always in their peripheral vision

is

so they can (again without a conscious thought)

make

your radio control driving

something has upset the car’s path from that they had predicted. Really, none of this is any different from what the driver of a

steering or throttle corrections

full-size race car driver experiences.

He

is

on the track where you

tions can vary so

perience to

know

the-limit

are automatic.

over a jump.

Matt

Francis,

Ciregg llodapp

(

Ryan

who won

drivers at the

Cavalieri, Travis Ainezuca,

the

an off-road car

The

surface condi-

with a dirt track that a simulator

how

far

the

(

left to right):

2WD modified buggy class),

Hilly Easton, Hilly Fischer,

132

take real-world ex-

you can push stretching-

like the tail-down, in-flight attitude

2005 R( )AR Off-Road Nationals included

Mike Truhc (who won

4WD modified buggy class),

to learn drive will race.

reality. It will also

just

maneuvers

steering, throttle, brake, or gearshift; all those actions

Above: The professional factory-sponsored

much

only comes close to

or she does not

have the mental time to think about what do with

skills.

way

Honestly, the best

if

Ryan Mayfield, and Adam Drake.

WALTZING The

secret

ON

DIRT

of learning to drive really rapidly on

dirt,

whether with a full-size car or a radio control model, is to understand that the car is nearly always going to be sliding in what will seems like out of control slides, even on the straights, but especially when braking or sweeping through a curve. W'har saves you from constantly spinning out is the forward momentum of the car.

Learn to keep the power on and

rections at the wheel feeling

of sliding

and

down

make

gentle cor-

you’ll discover the incredible

the short straights sideways

The secret is smoothness. You are, in effect, “dancing” that car on the dirt and sudden movements don’t just look awkward, they but under complete control.

often result in the car either sliding or entering a long series

of sideways barrel

rolls

down

the track.

POWERSLIDES

curve at more or

To initiate a powerslide, drive into the turn under par-

opposite lock

tial

throttle,

power

and once you are

in the turn,

apply more

turn the steering wheel in the opposite direction to

apply opposite lock. That should be enough to catch

and you can continue

to slide

on around the

Above: Apply just enough power when

Below: Usually

the quickest route

same throttle setting. This same maneuver you would do if

less the

the

you were trying to correct a full-size car’s slide across an icy curve. As you drive through the corner you will have to vary the throttle to maintain the same slide, and you may have to vary the steering as the slide becomes greater or lesser.

until the car begins to slide out. At that instant,

the slide

is

exiting the corner to keep at least one of the front wheels in contact with dirt.

around any corner

come within

cuts close to the pipe corner-linut. less

than an inch on every

133

lap.

The pros

like

Ryan Mayfield

(2) can

134

Above: The

start

is

ittiportaat but

it’s

even more important

to

make

it

through those

first

few turns

without spinning out or crashing.

Opposite above: One of the in

time

to

Opposite below: The

down

benefits of looking

avoid them as

track

may be 5

Jesse

feet

down

the track, rather than at your car,

Robbers has (5) at the 2005

wide but these pros keep

the middle of this short straight

and

cutting

left

ROAR

is

that

you

will see

spun-out cars

Off-Road Nationals.

their cars within

afoot of the quickest racing

as close to the edge of the pipe barrier as possible.

135

line

JUMPS AND On “air

WHOOPS

an off-road track, the cars time” on every

lap.

samples of

will get several

Jumps

are always part

of a com-

mercial otl-road track and are always included in any

National Championship car through the is

jumps

is

race.

Learning to control the

essential to

winning

races,

and

just as essential for having fun with an off-road car. First,

the

be sure that the car

jump and once

it is

is

headed

directly

toward

m the air, do not turn the steer-

ing until both wheels have touched

down on

the landing

jump. It’s a good idea to get down on the track and walk around it, imagining what your car must do to launch and land after each jump. When you drive side of the

the car around the track try to maintain the same path on each lap, then try another path in case part of the track gets too rutted during the actual race.

When you approach the jump maintain a steady how much setting can only come

rear wheels just

with practice. You want the car to land on the

down ramp of the jump.

balanced front to It

fly just far

had when

rear, it

it left

sion

to

down

on occa-

car usually recovers.

is

Often, the track will be designed so there are two or

You may have the choice to jump as a launching ramp to fly the car over the second jump to touch down on the ramp of the third jump. This is called a triple. Jumping two humps at once

If the car’s

weight

three closely spaced jumps.

fly at the

use the

rections in that altitude by applying the brake to force

the nose

and the

same altitude You can make minor cor-

should

the earth.

enough

an instant before the front wheels. In

practice, even the pros land front wheels first

throttle setting. Just

or by applying a bit

more

throttle to force

the nose up. Ideally, the car should touch

down

with the

is

136

first

called

doing a double.

It is

spectacular, but not always

the quickest faster if the

sailing skill,

it

jumps with which

ramp and clearing the tabletop on the downside. Whoop-dee-doos are a series of smaller jumps, around 6 inches high. Usually there are at least six in a row’ and there can be up to a dozen. You can drive relatively slow'ly through them like a snake or you can hit them at speed and try to hop from one crest to the next with the front wheels in the air and the rears just touching the crests. You’ll hear the pros driving through w'hoops in this style, blipping the throttle to grab traction for more front end air time at the crest of each whoop. or of pow'ering up the

car will likely be going if

the car

to land

is

air. Once you have developed the both ways, hitting each of the two or three

through the

try

jump

way around. Your

wheels are on the ground than

just

at a time is

enough speed and power and doing the double (or

to

make one

triple) to see

quickest.

Most off-road

tracks also include tabletops,

are essentially 4-loot

which

high jumps where the top 2

feet

have been scraped flat to form a tabletop. Actually, they

can be just about any

size. Again, you have the choice of jumping up onto the tabletop and perhaps leaping off

Above: This

is

a risky

even

Opposite above: The

safest

way

if a

to drive

slow enough so the car lands on like this

way

to

wheels hut

Opposite below: This

tires

car actually

the throttle while the car

it

loses time. It

can begin

made

was

in

straight,

all four tires find traction.

through a series of whoop-dee-doos

all four

modified buggy where the front

The driver punched

head for a landing. Keep the front wheel

curve follows, until

to pull the car the

a landing

to

keep the throttle application

effectively

moment

and continued down

midair that

137

is

works most

lifted the

with

4WD races

they touch down.

the track.

nose a bit just before impact.

Above: Most pros find Gregg Hodapp with

Below; Most accelerate

(4)

won

that they turn quicker laps by keeping air time to a mininnnn. the

2005

this technique,

ROAR Off Road Nationals 4WD modified buggy class

while “Flying” Billy Easton (5) finished ninth.

off-road tracks will provide at least one opportunity for a double where you can to fly over the valley between humps to land on the trailing side of the second

up one slope fast enough

138

hump.

Above; The

quickest path over a short tabletop is

Below: This

is

the

high enough to touch

most

risky

way

to

apply just enough power so the

to slingshot

but Team Associated pro

midair braking

to

is

down

Adam

rear wheels

out of a

series

of whoop-dee-doos,

Drake recovered with some

use the slowing

139

tires

car's

first.

for gyroscopic

stability.

nose

Above: Only practice

Do

it

will

right

Opposite above: There are two ways

Opposite below: Learn how like

pro Billy pMston

is

with his

tell

and

you how

to exit

close

you can handle a

a tabletop: Use

you can

UK) scale

fast

series

of short stutter bumps.

the car will just skim the tops like this buggy.

it

as a launch pad, or

get pipe barriers

lift

off and

during practice, rather than during the

two-wheel-drive modified buggy at the 2005

140

power down

ROAR

the slope.

race,

Off-Road Nationals.

half the time. Even

when

heading either righr or until

it

the

model

left, it will

is

traveling past you,

be coming toward you

passes your position and only then will

it

be

heading away from you.

When ing input

model is coming toward you, the steermust be reversed right-to-left. The words

the

need to learn to retrain your reneed to learn to adjust your reaction to the steering wheel controls. Fortunately, the

are simple, but you’ll

actions.

You

throttle

and brake control

will

trigger operates the

regardless of which direction the car or truck

heading. The disorienting part

DISORIENTATION relatively easy to control a modmodel is moving away from you. el traveling toward you almost the model is Unfortunately

car or truck

when

be

that the radio

transmitter does not move with the car or truck so your fingers must make any corrections. There are three techniques that you can try to see which one works best for you. Newcomers sometimes find it easier to aim the antennae on the transmitter in the direction of the car. You can tilt the transmitter slightly or twist it around m your hands. It’s awkward, but it can make learning a bit easier.

OVERCOMING THE "RIGHT-AT-YOU" You’ll discover that

is

same

may

it is

the

141

Some drivers car.

you, you will have a desire to alter

prefer to imagine themselves inside the

They remain facing the model

with this technique

is

at all times.

to disconnect yourself

The

way you want

trick

wheel

from the

ground mentally so you are right there with the model. Most drivers have talked to use the second technique, but they do find themselves imagining they are in the car

some of the race. The second technique

enced drivers

prefer.

When

Abc'\*e;

1l

model

is

path. Decide which steering

Ignore any concept of being

in

and just turn the w'heel the direction you turn the model. You can ease into this one by ap-

Then

it it

remove a crashed ear he/ore

142

it

move

the ve-

responds by heading the way you wish

simply apply more lever movement.

most experimoving toward

the corner nutr^hals ore olert they'll

its

and simply move the

plying just a touch to the controls to barely

the one that

the

in that direction.

v\’ant to

hicle. is

to turn

the car or truck

I

for

it

can impede your progress.

Above: Off-road

tracks are generally not

supposed

to

be muddy, but

where the track has been watered down

Below: These

six

Pro racers (Mike Truhe

and Jared Tebo

[5],

Matt Francis

to

[7], Travis

mud does

exist at the start

Amezucafl ],

Billy

[3]) are all at the limits of four-wheel powerslides through the

I/IO scale two-wheel-drive modified truck class at the 2005

ROAR

143

of many races

reduce the dust.

Easton

muddy

[8],

Adam

Drake

[6],

third turn of the

Off-Road Nationals. Jared Tebo won

this class.

144

CRAWLING OVER THE ROCKS

similar to that needed for any radio control car; the driv-

The most unique form of off-road radio control action is rock crawlers. These four-wheel-drive machines are es-

er has to “read” the terrain

sentially

monster trucks that have been modified to

climb near-vertical rock faces.

The

driving technique

Opposite: Rock crawling

is

and unconsciously apply the and steering (with two separate controls front and rear steering and throttles) that will keep

throttle, brake,

for

the truck climbing.

is

the finesse side of radio control competition where precise balance

and

control,

rather than sheer speed, are needed to win.

Above: Waterproof all

the electrical

The rock crawler

components and any off-road car can be driven

trucks, like this one, are particularly

145

in the snow.

adept at winter work.

1

ROAD

CHAPTER

RACING Want

how

to learn

go

to

really fast

with a radio control cor? Pay for in

on paved track

some

driving lessons

0 full-size cor on o real race track

and read Keith Code's books on motorcycle racing and how to marshal your available brain power. ou’ll discover that the skills needed to are the

same

skills

jor difference

you need

between

push that 1/10

to

and model

real

is

THE PAVED RACE TRACK if

you

the width of the course.

how large a curve

to

around the

would certainly be possible to and make abrupt powerslide donut turns at the ends, but that’s never the quickest way around. However,

and exit of each curve. you have 10 times the room to correct a driving mistake and 10 to select

The ma-

drive along

car,

room

car

track. It

on the

entrance, apex,

times the

scale car to its limits.

carve as their cars progress

are not

precise in the placement of the car

With an R/C

in a full-size

drivers to determine

you

V'ith a full-size road racing car

quickly run out of track

go really fast

like real car racing, the

around

your course for

the

track

is

quickest route

usually

the

the entrance, apex, and exit of the curve.

smoothest, which means that the major-

A

ity

race track for full-size cars

may be

10 times the width of the car while

5 to

most

tracks for radio control cars are 10 to 20

times the width of the

car.

like a

rectangular maze.

Most paved

It’s

up

actually

but

there’s usually

really driven like a se-

ess curves

traveling

with only a

where the cars are

dead ahead. That

choice of a curved path, however,

much

means

that you really do have the entire width

of the track to use for a corner.

to the

Opposite: The vast open space of parking

is

of connected

single long straight

tracks for radio control cars are simply

divided into a series of straights

of the track

ries

lot tracks

provides a wide choice of entry

only one fastest route around the course.

147

and

exit paths

VIRTUAL

ON-ROAD RACING

virtualrc.com),

There are several systems available that allow you to use

your Kyosho

a radio control race car transmitter to control virtual ra-

Virtual

dio control cars on a virtual track.

Some

designed with the option (usually a

may have

to purchase

port) or

way

you

an inexpensive replica transmitter

with the virtual training program. Virtual

Above: There are that allow

you

several video

to use

RC

to

you can

try. It

to learn to coordinate

real track

and crashing a

148

how

to drive

much

on a virtual race

quicker

throttle, brake,

and

hammering around

real radio control car.

help you learn to drive, like the Kyosho Virtual

a radio control-style transmitter to learn

can be a

your

steering control reactions than by

(v'ww.

programs

Racing (v\'V'w.bhmotorsports.com/VRCR)

are four brands that

transmitters are

USB

R C

Kyosho Virtual R/C Racing (through DuraTrax (w'uw.realrace.com), and

dealer),

R/C track.

a

LEARNING TO BRAKE If you are racing,

as close

you

will

want

to have full

power and That

to top speed as the straight allows.

means that you will be approaching the corner at the end of the straight at a speed far greater than the car can handle. Leave the throttle on and the car will spin or barrel roll into the crash barriers.

Fortunately,

most radio control cars are equipped with brakes. To apply the brakes, release the throttle trigger and push outward with your trigger finger to actuate the brakes at the end of the straight. Knowing exactly when to apply the brakes is something you can only learn by practicing. Learn by applying the brakes too soon so you need a

Go

farther

fore

bit more throttle just make to the corner. and farther into the corner on every lap be-

of control in spite of the brakes, try a gentle application of near full throttle. The spinning tires will grab

applying the brakes until you finally reach the

point where

it

is

too late and the car spins.

On

more

the

barely

makes

it

around the corner.

If the car

traction than they did while just sliding under

braking and the car

next lap apply the brakes just a bit sooner so the car

on around the

seems out

will often catch traction

corner.

Above: For practice find cm empty parking lot with no cement barriers for at least 100 in any direction and start with a series of larger and faster figure 8s.

Below: On some to

tracks

it's

feet

quicker to brake late (a late apex) before turning into the curve

cut across the corner marker curb on the

149

way out of the

curve.

and motor

LEARNING TO CORNER

as much throttle as the car can take without spinning out. Try to hold that setting until the car reaches the apex of the turn. The apex is the point where the

you apply

Most on-road cars have enough power to be able to slide all the way around the curve with the tail out. That, however, is not always the quickest way around and it is difficult to maintain such a powerslide. For most on-road cars, the

cornering speed will be highest

if

the car

is

car

on

usually easier to learn

how

full throttle, and if it seems to want to, let the on out to the far side of the track as it accelerates away the next corner. Apply this combination of brake and steering to a 180-degree corner. Brake and steer into the corner while

usually quicker to run

Above right: On Effectively

down

marker curb as possible

really tight curves,

it is

mid-apex turn can often work because the car time

and

is

is really

spent braking and then accelerating with a quick

turn at that apex.

the outside of the straight to

and

cut through the corner

curve back into the middle of the next straight.

often quickest to have the

you are applying the brakes and

earry the slide

When

throttle as quickly as

only in the corner for a brief time; most of the cornering

apex at the middle of the

sliding into the curve slightly sideways.

At the point where the car headed out of the to

more

with larger radius curves. For tight curves, the previous

car slide

It is

you may actually have

With practice you may discover that the quickest way around a 180-degree corner is to carry the initial cornering speed just a bit farther around the corner than with a 90-degree corner before you apply full throttle. Real racers refer to this technique as a late apex. It works best

the corner at a relatively slow speed. At that point, gently

left:

slowest, although

sary to avoid a spin.

squeeze to

as close to the corner

its

to apply throttle before reaching the apex.

you can without forcing the car to spin out. Again, let it slide on out toward the outer edge of the track if neces-

to control the throt-

tle and steering to get a car through a corner quickly if you practice first on 90-degree turns. You can motor around the other turns on the track until you get the 90degree turns learned. Apply the brake and turn the steering at about the same time so the car reaches the apex of

Above

going

car reaches the apex, apply

the very edge of breaking traction. It is

IS

begun

corner, gently apply

the car out of the corner

150

and down

more

throttle

the straight.

turn.

Above left; Learn

to

make

both sharp turns

and broad

turns with the car drifting sideways through the full length of the turn.

Above right: When you have some experience, try driving on one of the real radio control or set up your own with some tnetal pie plates to mark the apexes of the corners. Below: Pat Byrne

cuts as close to the red

and white curb

as he dares with his 1/10 scale electric

151

tracks

Tamiya 1994 McLaren FI

car.

THE RACING LINE The

racing line

drivers follow

is

the path that the quickest cars

around the

along the very edge of the

The track, and

track.

racing line

is

and

never

in general, the rac-

makes the largest possible radius for each curve. On some tracks, each turn is separated from the next by a 10 foot or longer straight so you are driving in a pating line

tern of straight, corner, straight, corner.

On

tighter

and through most of the corners on a dirt track, the corners are virtually connected so you are going from tracks

corner to corner with just an occasional straight in between. In effect, the track

There

is

no proven

is

series

of ess curves.

best path through a series

of curves other than to keep your route as smooth as possible. The drawing illustrates one possible path with late

here

apexes on both is

left

to try to carry as

practice, the car

right curves.

Above: to

previous straight as far as possible through ess curves. In

The technique much of the speed from the

and

way

would

to the first apex

likely be sliding

when

Practice running behind one or two cars to get used to using your peripheral vision

keep track of where your car

Below: The RJC

tracks

is

going, as well as where the other racers

may

be heading.

have elevated driver stands with the course marked with boards or like this

one at

Mohr Raceway

152

in

Aurora, Colorado.

sideways

all

the

a quick jab of throttle should

PVC tubing

Above;

On

ess curves, the

and

racing line can be a combination of different lines depending on the track conditions

the positions of the corner to

marker curb and

barriers,

but

it is

almost always quickest

find the shortest route between the inner barriers of the two curves.

153

straighten

it

out enough so you can move the steering

to the opposite direction to carry the

same

slide

and

start. It

same speed to the second apex. When that is reached and the car has slid around the corner enough to be pointing in the general direction of sentially the

second apex

the next straight, gently apply throttle until the car

and

accelerating at full throttle

corner to head

down

drifting

can result

in

two cars crossing the

car

must be

allows

is

on around the

ation.

the next straight.

it

set

to idle

up so the centrifugal or is

You must

adjusted to provide

Most

SET,

GO

also be prepared to brake

longest straight.

ner that would occur track announcer.

Your

amount of time you

of cars

at the first cor-

down

started at once. The cars on voice command from the

if everyone

are flagged off one at a time

total race

time

is

R/C

bly

ahead to

Above: The start

is

It

made near

would be wise

the straight at full speed).

for

more

throttle if you

want

get

by the race director calling out one car at a time,

154

to

will find that the

braking point and proba-

as quickly as possible.

followed by another at about one-second intervals

You

later

one of the most unnerving aspects of a race

races are started

the middle of the

to practice starting

much

corner requires a

adjusted by the

lost waiting for the cars

but most

and turn

from a dead stop (position your car near the edge of the track so you are not rear-ended by another car heading

radio control car races are usually started one car

at a time to avoid the crashed pile

lever clutch that

maximum acceler-

that first corner.

Usually the starts are

READY,

line together

but one being the winner by a dozen feet (and few fractions of a second). There’s not a lot of skill involved because your time doesn’t start until you are rolling. The

es-

avoid pile-ups at the first turn.

up

to full racing speed

SIDE-BY-SIDE

In an organized race there

the track.

The

WRECK RECOVERY

COMPETITION may

when you cannot avoid you cannot avoid being hit by another car. Most often the impact will spin your car. Be prepared to crank the steering right or left and apply full power to do a partial donut spin to get the car headed the right way down the track. You can practice this any time your car spins out. The moment you see the car spinning, hold your throttle finger ready to squeeze on more power and opposite lock steering to get the car heading the correct way down the track. During a

be a ciozen other cars on

staggered start will

keep the cars spread

around the track for a few laps, but you will eventually find that you are sharing track space with at least one other car. Try to focus on just your car and try to maintain the

same racing

practice laps. If the

line

you have been using during

nearby car turns into you, try to

ig-

you are sure the two might touch and only nore it move the steering wheel to alter your course gently then to avoid collision. fraction needed the until

Above

race there will be times

hitting another car or

left: This pair of 1/10 scale electric touring cars are running a bit too

Above right: As

they enter the corner, the red car turns in a bit too quickly

to lose the rear

Below: The

end as

it

hits the rear

quarter of the green

close.

and

car.

red car forces (probably by accident) the green car into a spin,

but the slight impact also upset the red

155

car’s

path through the corner.

begins

12

CHAPTER

PAINT

SHOP These racing machines are vehicles in their own but each is supposed to be a recreation of a real truck or automobile.

HIS

IS

right

NOT MACHINE RACING BUT RADIO CONTROL MODEL CAR AND TRUCK RACING.

Most of the

vehicles look very

much

like full-size cars or trucks. It is the

body,

of course, that brings the appearance of realism to the model; a realism

enhanced almost

infinitely by the

track. In the case

of nitro-powered touring

the

sound

performance of the car or truck on the Indy

cars,

and FI

cars,

even

is real.

BUYING A BODY

plastic similar to that

The majority of the model cars and are sold ready to

body.

cars.

Most of

run with a

fully

trucks

plastic

tougher and more

the kits also include fully

painted bodies, although some offer the

all

used in 1/25 scale

The bodies

in the ra-

made of much

flexible plastic

than

the styrene used for display models. All

who

and vacuummolded from clear Lexan plastic. The clear plastic is painted on the inside so serious radio control racing cars

would rather do it themselves. There are hundreds of painted bodies available with dozens of choices for

kits.

dio control cars are

painted

option of unpainted bodies for those

model

trucks have bodies that are

of the popular

No painting is needed; just punch

the tough Lexan provides the outer shell.

some holes for the body-mounting posts and start racing. The lower-priced cars and trucks usu-

The Lexan looks like deep wax shine and is far more scuff-resistant than any paint. The Lexan is also very impact- and tearresistant and is easy to clean.

chassis.

ally

have bodies modeled from colored

Opposite; You can make any radio control car your personal creation with a hand-painted body that

like this

1/10 scale

Team

Losi electric touring car

was airbrush-painted by Chadd Brockman.

157

PAINTING CLEAR LEXAN BODIES You can

also

buy unpainted

any 1/12, 1/10, or 1/8

The bodies

clear

Most hobby shops

Lexan bodies for almost

cial

carry one or

more brands of spe-

paint for Lexan bodies, like Pactra’s Acryl Racing

which is available in both bottles and spray Most lacquer can curl the bodies, and most enamand other acrylic model paints won’t stick to the

Finish,

scale radio control car or truck.

trimmed along the lower edges so the only construction work you need to do is to punch the holes for the body-mounting posts. Use a 1/1 6-inch drill bit to locate the body-mounting holes, then enlarge the hole to fit snugly around the post with a hobby knife. The body is retained on the body-mounting posts by bent

cans.

pins that are furnished with the chassis.

ing holes so the paint isn’t accidentally applied to the

Some of the bodies are sold just as they come from vacuum-molding machine with a massive clear plastic skirt that must be trimmed away. Use a felt-tipped pen to mark the exact outlines of the wheel cutouts, then trim the body along the lower panel lines and wheel well lines. Mount the body and cut any holes for air cooling or open windows.

outside of the body.

are usually

els

Lexan. Racer’s Edge offers an aerosol paint that ly as reflective as

chrome and

is

near-

also has color-changing

paints for Lexan bodies.

Mask

off the outside of the body and any mount-

Some of the unpainted

bodies are

windows premasked. If the windows are not masked, it’s best to mask them using automotive masking ^ape. Cover the window about 1/4-inch beyond its final size, then trim the excess tape. Be careful when you slice the tape so you cut through just the tape and not into the plastic. sold with the

the

Above: With exception of some of the 1/24 and 1/12 scale cars, most of the competition radio control cars have rugged Lexan clear plastic bodies that are usually painted on the inside so the plastic protects the paint.

158

so al

Remember, you are painting the body on the inside every color must be applied in the reverse of the usuorder. The chrome parts like headlights, bumpers,

and handles can be painted first using the bottled paint and a brush. If you want flames or other special effects, apply them next. If you are going to spray-on the flames, mask off all of the interior except for flame shapes. You can use aerosol cans of the special Lexan paints or apply the paint with an airbrush. If you hav'e experience with an airbrush, you can spray the body without masking.

Most racing decals are self-adhesive and designed on the outside of the body. You can, how-

to be applied ever,

in

use conventional decals applied face-down. Brush

some

cal will

clear Pactra Acryl

Racing finish where the definished body can look as realistically wild as

be applied and slide the decal off its paper back-

Chadd

The paint might attack some brands of decals so try the paint on a scrap of decal before working on the model. If the body is going to

the best-appearing car in a concours competition.

be one color you can apply that color

ROAR

Brockmann’s truggy

ing and into the wet clear paint.

Apply the can.

Most

final color

colors will look best if you apply a final coat

dio control car or truck.

The

Above; The manufacturers usually a rainbow of color schemes

Below: Crashes

races also offer a trophy for

has specific rules for concours competitions at ROAR-sanctioned events that can serve as a guideline if you are wondering what constitutes a prize-winning ra-

last.

of white, grey, or black Pactra Acryl Racing Finish to

in

monster truck bodies.

Most of the organized

with an airbrush or aerosol

eliminate any translucency in the colored paints.

class

to fit

offer a

wide choice of bodies

each of their popular chassis.

are inevitable but the flexible Lexan body

helps protect the mechanical elements

159

and

the

body

itself

Above: Most of the to

bodies are

support the body and metal pin

Below:

mounted on 1/8-inch

Failure to insert the pins properly can result in

and a

loose

posts with soldered washers

clips inserted in holes in the posts to retain the body.

some

distracting

body can be grounds for disqualification during a

160

body

race.

actions,

Above; You can

start with a simple one-color

and numbers and sponsor

paint scheme and apply self-adhesive flames

logos to the outside of the body.

Below; Complex paint schemes

like these

are easily accomplished

with the special paint for Lexan bodies applied with an airbrush.

161

Above: The so

clear plastic bodies usually

have masking tape already applied over the windows

you can simply spray or brush on the paint

162

inside

and peel

off the stickers.

Above: Chadd Brockman used several layers of masking tape to produce these two-color flames. He painted the green first, followed by a new mask for the black, then a mask for the metallic red, and a mask for the silver for truck bed. He finished off the paint with a primer coat of white on the body and black beneath the bed Finally,

to

eliminate any traiislucency in the paint.

he peeled off the masking tape from the clear windows.

163

Above: This monster

truck body was also painted with masks; one for the pink,

followed by a second mask for the black, and finally the metallic blue.

Opposite above:

Wdiite

primer was used

Black primer was used

The D-shaped hole

is

to

to

back up the blue metallic paint.

back up the

silver bed.

for cooling air to reach the nitro-powered engine.

Opposite below: You can

super-detail the clear plastic bodies.

Chadd Brockman used a hobby knife to carefully trim out the side windows, leaving the rear window half-down. He slit along the top of the side front windows to

simulate the plastic air-blockers on the real trucks.

164

165

166

Opposite; Brockman painted the black straps for the fuel tank and the black bed protector before applying the silver paint for the fuel tank

and

strips

with a brush

the beige paint for the bed.

Above: Mike and Sam Urban updated and detailed these Tamiya 1/10 scale electric McLaren Fortmda 1 cars to 2004 cars with new ears, lengthened wing side panels, and new barge boards that identify the later cars.

from 2003

They

also painted

and

lettered

them with

decals they created

167

on

their computer.

1 CHAPTER

RACE TRACKS FOR R/C CARS There is no reason you cannot run your lot or vacant o control cor in a and never even look ot a race track.

RIVING ALONE

AROUND

CO drive the car, but to judge

A

it

RANDOM

SPACE

IS

A

field

GOOD ENOUGH METHOD OF LEARNING

soon becomes boring because you have no benchmarks

whether or not your

skills are

improving.

There are over 1,000 radio control race cracks in America and many more in

Europe and

site

Asia.

You can find

a nearby crack by searching the

ROAR

web-

(www.roarracing.com) under track locator, by looking in the Yellow Pages

under “Hobby and Model Construction Supplies,” or log onto the major manufacturers’ websites a crack, he or she

YOUR VERY You can

and look

should be able to

OWN

road

lot or in a

cars.

own

you where

traffic

If

cones or

enough

cars for a race.

how about 90

percent of radio

to use

your private race

and tuning school, you

need some method of timing laps. Get a friend to time your laps with a stopwatch or buy one of the in-car telemetry devices for lap timing that are described in Chapters 9 and 10. The

the corners. Get a few friends together

That’s

you want

will

off-

even water-filled paper cups to mark so you have

to find the nearest track.

track as a driving

race

empty

vacant field for

Use a few

tell

RACE TRACK

certainly build your

track for on-road cars in an

parking

for dealers near you. If the dealer does not have

commercial tracks use expensive transponder systems that are similar

control cars are raced.

those used for real race cars.

Opposite- The races are usually started one car at a time about one second apart so

you are

effectively driving

169

alone hut in

traffic.

BUILDING A DIRT TRACK The major hurdle to overcome when building your own dirt track is finding the space. If you intend to race nitropowered cars, you may also have to find a space far enough away from any homes so the noise is not offensive to others.

A

dirt track for radio control cars

is

very

similar to the dirt tracks that are used for bicycle

mo-

tocross but the radio control car racing track can be considerably narrower.

The

racing lanes

on the

larger radio

control tracks are about 4 feet wide. You’ll want to in-

clude rows of three jumps that can be taken one at a time or tripled by the brave in a single leap.

Most

dirt tracks

which are 4-foot-high jumps with the top cut off so there’s a 3- or 4-foot flat and just a 2foot elevation. The racers can either land on the tabletop or gut it out and try to clear the tabletop and land on the downside ramp. A few dirt tracks also have banked turns. also have tabletops,

Above; The high-banked turns and

make

it

You can use

a shovel for

all

of this but the sane way

is

to

rent a small bulldozer or skidsteer.

The commercial The

existing soil

elevated drivers’ stand at Rat

is

Raceway

one of the most interesting nitro-only off-road tracks

dirt tracks are

in Denver, Colorado,

in the country.

Below: A used intermodal container doubles as an elevated drivers' stand and the officials and timekeeper’s office at Rat Raceway.

170

not bulldozed earth.

used to shape the jumps and tabletop.

buc a 6-inch layer of special soil is then added to the top. are not always anxious to share their secret

The raceways dirt blends,

but most start with the finest sandy

soil

and

add loam and perhaps some other local soils until they get a mixture that will pack down nicely but still provide grip for off-road tires.

Few

tracks have the high-banked turns like Rat Race-

way, but those that

enough is

to

pack

do use

soil

down and hold on

have

soil

that

is

firm

a 45-degree slope. Clay

too slippery hut certain kinds of loam from a sod farm

might be a place to

start.

The

surface

on Rat Raceway

is

compacted enough so that the track is actually swept with a blower to remove the dust and leave a very rough and al-

most pavement-like

surface. Three-foot high walls

of left-

over 4x6-foot concrete slabs support the high banks at Rat

Raceway with a row of hay bales to catch the out-ofcontrol cars before they fly off the top of the bank.

Above:A

4-inch drainpipe with 90-degree elbows buried in the dirt makes excellent course barriers for ojf-road evatts

one at

Below: The view from

RC Madness in

Enfield, Connecticut.

the 9-foot-high drivers’ platform (on top of a used intermodal container)

provides a perfect view of every corner on Rat Raceway.

171

like this

Above

left: The elevated drivers’ stand at

The

electronic scoreboard

because

Above right:

it

RC Madness in makes

Enfield, Connecticut, has

the racing

more enjoyable

provides easy-to-read lap times

Railroad

ties

and 3-mch-thick

with hay bales

and positions during

for as

many as

a dozen drivers.

and mechanics

the actual race.

concrete slabs support the high banks at Rat Raceway,

to catch the cars before they fly off the tops

Below: Small adjustments

room

for spectators

are easier to

make when you have

172

of the walls.

this kid

of perspective.

INDOOR RACING

have your

own indoor

sion of the building owner

hundreds of dirt tracks in door tracks are obviously limited to electric-powered cars. Dust is the major problem with indoor tracks so most are treated with chemicals used for indoor

insurance

horse arenas.

feels

outdoors but there are indoor warehouses. The in-

floor

will do. If

you

Above: Mohr Raceway has

you expect

to race with others.

A

A

concrete

few of the com-

knit indoor-outdoor carpet (the kind that looks

much

like felt). If possible,

10-foot or taller ceiling so

you can

install

indoor off-road track that can be used even in Denver, Colorado’s chilly winters.

173

and

find a warehouse with a

portable elevated drivers’ platform.

are attempting to

this

if

just fine for radio control cars.

mercial indoor raceways cover the floor with the tight-

Tracks for on-road cars are often located indoors.

Any empty warehouse

is

you will need the permisand you will want investigate

track,

Typically, a dirt track will be

some kind of

BUILDING A PAVED R/C RACEWAY Essentially, building a race track for trol cars

means finding some

on-road radio con-

place where you can pave

a perfectly flat area at least the size of a tennis court. If

you are racing with friends, you may even be able to find an existing abandoned tennis court. Most of the purpose-built paved tracks are paved with macadam (tar and sand; also called blacktop). The blacktop has the advantage of not needing any expansion joints, and if does crack, it can be repaired easily. If you are careful, the seams will be as flat as the rest of the course. The commercial track builders surround the track with a foot-high bank of cinder blocks, concrete blocks, or railroad

ties

so out-of-control cars will be contained within

the track area.

Above: The parking in 4-inch

lot

race coarse for the

Hobbytown USA

Tall Classic race

is

liefmed with 90-degree bends

drainpipe with sandbags to secure the pipe at the corners.Here we go with the caption for that one.

Below:

I'he timing in

and

Hobbytown USA

Fall Classic

supported on a pair of 3-inch

PVC pipes.

scoring system used at the

Aurora. (Colorado,

is

174

parking

lot race

DEFINING THE COURSE Once the track fine the

is

Rat Raceway uses corrugated flexible drain pipe to

PVC drain pipe is more common. Mohr Raceway and RC Madness dirt tracks use PVC pipe and PVC pipe elbows to anchor the lengths of pipe into the soil. If you opt for PVC pipe outdoors, it define the course, but 4-inch

complete, you’ll need something to de-

course itself

Some of

the tracks in Europe are

dedicated raceways with grass infield areas similar to old

Malibu Grand Prix go-kart tracks. Most of the race tracks in America are designed so the track can be

can be anchored with foot-long spikes or sandbags

tocross tracks to

commercial tracks are defined by curbs that simulate the curbs on a real race track. Used farming plow discs are

change the course from one weekend’s

perfect curbs if they are painted a bright white

races to the next.

Above: Four-inch drainpipe with 90-degree elbows buried for off-road events like this one at

like

Hobbytown USA in Westminster, Colorado. The corners on many of the the temporary parking lot course at

changed by moving portable barriers. The cars are directed onto specific parts of the course by the portable barriers. Similar systems are used at most outdoor mo-

in the dirt

RC Madness

175

makes

excellent course barriers

in Enfield, Connecticut.

and

red.

Above: The to

dirt

is

usually a complex mixture of local topsoil, sand,

and

provide a course that will not be churned into endless ruts by spinning

of the

RC Madness

track

makes

it

necessary to water

down

176

other materials

tires.

The loamy nature

the track between races during the

summer.

Above: The Rat Raceway to

On

in

Denver, Colorado, has enough clay in the

soil to

hold up on the two or three high-bank curves on the

this surface the race

make

crew sweeps off the loose dirt before each major

177

it

hard enough

track. race.

THE DRIVERS' PLATFORM in

com-

race director can operate

fabricated stairs

drivers’

about the height of a second-story floor in a house. Some tracks, like RC Madness, have a special structure. Rat Raceway used an empty shipping container for stand

railing

is

Above:

a patio deck for

Mohr

surrounds the upper deck.

assemble an elevated

drivers’

ing pipe and tees like that at

If you arc creating a private track, try to find

so the drivers have a better perspective like

and cut a window in the side so the from inside the container. Preand railing lead to the top and a sturdy

the drivers’ stand

of the commercial racetracks have one thing mon: an elevated drivers’ stand. Typically, the

All

on how

some means

to elevate the

Mohr

driving position

their cars are handling. This platform

was made

Raceways, but you can use or rent some portable scaffolding.

178

Some

track builders

stand from used scaffoldRaceway.

Above; Mohr Raceway fined with

is

typical of most

6x6 beams anchored

Bottom (and

left:

One

Try

to

plow

discs

in

America: a tennis court-size expanse of flat blacktop. The course

painted red and white. This

of the advantages of an organized race

you’ll likely be

Bottom right:

on-road tracks

into old

one yourself between races)

find you is

own

to set

is

is

that there will be corner marshals

your car upright when

it

turns

turtle.

place to work, like the upended cable reel that Dante Rodriguez

using at Rat

Raceway

in Denver, Colorado.

179

is

the view from the elevated drivers’ stand.

de-

Above: chairs,

where you can

If you race frequently, you'll

and some kind of sunshade

like this

want

to invest in

group at the

a folding

ROAR

table,

Ojf-Road Nationals.

Bottom: There is usually a waist-high wall in front of the drivers’ platform your car and make minor adjustments before climbing up onto the stand and

start

180

driving.

Above: The organized

race meets provide transponders that can be temporarily

attached to your car so the scorekeeper can record your

At some

races the

group

will

Below: There The race steward

number of laps.

even provide a readout of your individual lap times for the entire

will explain

is

race.

a drivers’ meeting before every race meet.

how

the races will be run

181

and what

is

expected of the drivers.

Above: The

drivers’

meeting at the beginning

of

a Colorado Crawlers

(

www.rccrawler.com)

rock crawler event in one of Colorado Springs' city parks.

Opposite: Jason Hensel and Brad Dumont lay out a rock-crawler course with cut halves of yellow tennis halls while Aaron Busenbery directs the work at a Colorado Crawlers event.

The system, coupled with use of only electric-powered rock crawler makes it possible for the group to hold events in city parks.

182

cars,

183

Above: The This one, at

RC Madness

larger outdoor

and indoor

in Enfteld, Connecticut,

is

tracks

have elevated drivers' stands.

about 10 feet high

184

to

provide the best possible view.

&

i

CLUBS

i

PUBUCATIONS HERE ARE RADIO CONTROL CAR RACING CLUBS AND TRACKS ACROSS AMERICA.

ROAR

(www.roarracing.com) has a region-by-region

listing

of hundreds of tracks at both

commercial shops and clubs. The simplest way to get started racing

The organized

races are

run with cars in specific racing classes

so 1/10 scale buggies will usually run in a separate class

themselves are also broken

down

into qualifying events

winner. If there are fewer than 12 entrants, there’s really

like

from 1/10

to attend their races.

those in the previous chapters, scale

monster

and main events

no need

is

trucks.

to determine

The

races

an overall

for the qualifying events.

CLUBS ROAR is the national nonprofit corporation organized to promote the sport of radio controlled model car racing. ROAR rules have been the guidelines for R/C car racing for over 35 years. ROAR does not run races, but it does sanction races from the club level to national championships. All ROAR members are eligible to enter these races. ROAR is the North American representative to the International Federation of Model Car Racing (IFMAR). ROAR has 200 and Canada. These clubs pay only $35 per year to be sanctioned and covered by the member accident Annual ROAR membership is $30. The member is insured at any ROAR sanctioned event, entitled to vote on important rule changes, and will receive ROAR newsletters and a copy of the latest rule book. IFMAR (www.ifmar.org) is the primary sanctioning body for world championship radio control races for both electric- and nitro-powered cars. In America, ROAR coordinates rules and races with IFMAR.

clubs in the U.S.

and

liability

insurance.

ROCK CRAWLER CLUBS

PUBLICATIONS RC

Oregon Radio Control Rock Crawlers (ORCRC): www.orcrc.com Victorian Radio Rock Crawlers (VRRC)

Driver magazine: www.rcdriver.com

Xtreme RC Cars magazines: www.rc411.com Radio Control Car Action magazine: www.rccaraction.com

ROCK-CRAWLING

Radio Race Car International magazine (British): www.radioracecar.com AMT (auto-model + technik )(German):

Radio Control at Off-Road.com, an off-road and rock crawler webzine; http://rc.off-road.com/rc/

Rock Crawler, rock crawler

www.vth.de/Modellbau/ amt/amt.htm

website:

http://rccrawler.com

185

i

SOURCES OF

I

SUPPLY

APS Racing

(see

Magma International)

Byron

CVEC

AXI Motors: www.hobby-lobby.com

Academy

(see

MRC)

Fuels:

www.byronfuels.com

Power Systems: www.cvecpowersystems.com Carisma

(see

Horizon Hobby)

Corally USA: www.corallyusa.com

Ace RC: wwu'.acehobby.com

The Crawler

Airtronics: www.airtronics.net

Store: www.thecrawlerstore.com

Dremel Motor Tools: www.dremel.com

Associated Electronics: w’ww.teamassociated.com Astroflight: www.astroflight.com

DtiBro:

Bender Customs: www.bendercustoms.com

www.dubro.com

DuraTrajc www.realrace.com

186

Nomadio: www.nomadio.net

Dynamite Racing: www.dynamiterc.com

Novak

ElectriCalc: www.slkelectronics.com/ecalc

FMA

Direct:

www.teamnovak.com

Electronics:

ONA Racing: www.ofna.com

www.fmadirect.com

Team

FlexTek RC: wu'vv'.flextekrc.com

OS

Fox Manufacturing: www.loxmanufacturing.com

Orion: www.teamorion.com

Engines: www.osengines.com

Futaba: wwu’.futaba-rc.com

Picco (see

Great Planes Model Manufacturing:

Polk’s Hobbies:

OFNA)

www.polkshobby.com

wuw.greatplanes.com

Power Racing: www.powerracingrc.com

HPI Racing: wuw.hpiracing.com

Pro-Line Racing: www.prolineracing.com

Hacker Brushless: wu'u’.hackerbrushless.com

R C Guy Products: www.rcguy.com

Hitec: u'ww.hitecrcd.com

RD Logics, Inc.: wwu’.rdlogics.com

Horizon Hobby: vv'U’U’.horizonhobby.com

Racer’s Edge: www.racers-edge.com

Hot

Radio Shack: www.radioshack.com

Bodies: u'W'U’.hotbodiesonline.net

Hudy Ultimate

RC Dyno

Professional R.C Products: u'uw.hudy.net

IMFXRC: u'ww.imexrc.com

Schumacher Racing: www.racing-cars.com

Bodies: w’U’U’.jsbodies.com

OFNA)

Scorpion 4x4: www.scorpioncars.com

Gears: u'ww.kimbrough-products.com

Serpent Motorsports: www.serpent.com

Jammin Kimbrough

KO

Propo

(see

USA

Spektrum

(see JR)

(see

Horizon Hobbies)

Kyosho: www'.kyosho.com

Tamiya: www.tamiyausa.com

LRP: u'u'u'.lrp-electronic.de

ThunderTech Racing: www.thundertechracing.com

Losi (also see

Tower Hobbies: www.towerhobbies.com

Horizon Hobby): w'w'w.teamlosi.com

MRC (Model Rectifier Corp.): wu'w.modelrectifier.com Magma

(see Associated)

Red Cat Racing: www.redcatracing.com

JR: u’W'U’.jrradios.com J. S.

Systems: www.rcdynosystems.com

Reedy motors

International:

Traxxas: www.traxxas.com

www.magmarc.com

McDaniel division of Sonic Tronics

Inc.:

Treadz: www.treadztires.com Trinity Products, Inc.: www.teamtrinity.com

http:sonictron-

ics.com/ xcart/ customer/home.php

Mohr

Tyco RC: www.tycorc.com

Venom

Racing: w'w'w.mhorrc.com

MotoCalc: wwu'. mo tocalc.com

Mugen

Virtual

Racing: w'uw.mugenracing.com

Racing: www.venom-racing.com

RC

Virtual

Racing: www.virtualrc.com

RC

Racing

(see

Kyosho)

Nitrous Express: w'U'W'.nitrousexpress.com

Xray USA: www.teamxray.com

New Era Models: wuw.neweramodels.com

Yokomo-USA: www.yokomousa.com

187

GLOSSARY 2WD:

Two-wheel-drive chassis that provides power only

deliver electrical

power

to the motor.

Comm is also used

commutator

the rear wheels.

to describe the relative size of the

4WD:

motor. High-torque motors often will be described as having a “Big Comm” or a relatively large commutator.

all

Four-wheel-drive chassis that provides power to

Small

four wheels.

in the

Comm motors are usually those designed for sus-

tained high rpm.

AFTER-RUN OIL: Special oil to be used down the engine in a nitro-powered car.

after shutting

CHANNELS: The

dedicated radio-transmitted com-

mands from

radio control transmitter to receiver. Each

ANTI-ROLL BAR: A wire or rod that connects the right and left suspension pieces to limit how far the right can move up or down compared with the left. The bar is de-

channel

transmit only

signed to allow the right/left suspension to compress or

speed control through the

rebound normally. tries to

When just one side

compress, the anti-roll bar

commands on

on the

control servo.

Some

rock

ANTI-SQUAT: See

CYANOACRYLATE ADHESIVE:

caster.

Battery capacity

usually measured in milliamp hours (mAh). battery has potentially 720 milliamps. In tery will have

something

less

than

its

A

720

reality,

See CA.

DROOP: The

BATTERY CAPACITY: The measure of how long the battery

maximum current draw.

for

channel for independent control of the front and rear

by trans-

motor/axle units.

function at

one

least two;

ESC and one for the steering climber cars may have a third

ferring the pressure to opposite side of the chassis.

will

that specific

car requires a separate

channel so most model cars have at

of the suspension

resists that

will

frequency. Each control

distance each of the four suspension arms hangs from the chassis. It is used as a comparative dimension so the amount of droop on the right of the suspension should match that of the left of the suspension.

is

mAh

the bat-

rated capacity.

It is

not necessary that the amount of droop at the rear

be the same as the amourit of droop at the front.

BUGGY: Short

for

dune buggy-style off-road racing

cars.

DIFFERENTIAL: The center mechanical component of the

CA: Short for cyanoacrylate adhesive. The best-known brand is Super Glue, but there are some special formulas for modelers like “Hot Stuff”.

driven axles

CAMBER: Looking

DRIFTING: The current popular use of the term drifting

that tires have

compete in style contests with the tail of car sliding around in a prescribed pattern. The sport of drifting was born in Japan, but it is now popular around the world. The more traditional meaning of drifting is to describe a car chat is sliding around a turn, usually with tail of the car hanging out far more than the front. Off-

is

vertical.

Caster

is

line that

is

the steering pivot

allows the out-

is

and

road cars are drifting through virtually every corner.

usually set as a positive angle with top of

ELECTRONIC SPEED CONTROL

the imaginary caster line leaning backward toward the rear axle.

cars. It

farther than the inside wheel

to describe cars chat

the term used to describe the angle

between the imaginary

travel

through a corner.

at front of the car, camber is the angle compared to vertical. Positive camber means that the tops of the right and left tires are closer than the bottoms. Negative camber means that tops of the right and left tires are farther apart than the bottoms of the tires.

CASTER: This

on most radio control

side wheel to

out any pressure from the steering controls. The same

from the

measurement

motor’s speed.

at the rear

of the car

is

(ESC):

The

solid-state

electronic device that transmits the radio control signals

Caster helps the car maintain a straight course with-

called anti-squat.

receiver to the

COMM: This is short for commutator, the portion of the

FREQUENCY: The

motor’s rotating armature where the brushes ride to

trol

188

motor

to increase or decrease the

radio control transmitter emits con-

inputs on specific radio frequencies that are desig-

nated by the Federal Communications

“Channel

IT

Commission

move through the cylinder and The piston’s resistance

like

or “Channel 78”.

cylinder.

the fluid inside the

the fluid inside the cylinder helps control

HOOK

en the action of the springs.

UP: Slang for a car getting good traction; where

the tires bite into the surface

with

through and damp-

in traveling

little slip.

STADIUM TRUCK: A

MONSTER TRUCK: Recreations of the massive trucks

that

fit-

is

racing version of the monster trucks

part monstet, part Baja-style racing pickup truck.

ted with giant earthmover-size tires.

SWAY OVERSTEER

(SEE

ALSO UNDERSTEER): When

the car slides off the racing line nose first. Also,

is

when

and

left

to determine

and

front wheels

how

close the right

tires are to parallel

when looking

dowTi on the chassis. If the forward edges of the wheels are

needed to keep the car tracking around the deOn some dirt tracks the car may have so

closer together than the inner edges of the rear of the wheels,

is

said to oversteer

if less

the chassis has toe-in. If the inner edges of the right

sired curve.

much

Bar.

steering in-

cornering, the car

put

TOE: The measurement

a corner with front wheels sliding first so

es traction in

BAR: See Anti-roll

a car los-

oversteer that steering

opposite direction than the car

wheels and

actually turned in the

is

is

sliding.

This

is

some-

tires are farther

and

rear of the front wheels

some

times called opposite lock steering.

TRACK WIDTH: The the right

The piston acts on a pivoted top and bottom. The

connecting rod that

is

connecting rod rotates the crankshaft. Also, there

is

how

fast the piston

the fluid inside the

tires

can also be adjusted

of toe-in or toe-out.

will

left tire.

On some

cars the track

be slightly wider or narrower than

the track width at the rear.

THROTTLE NOTCHES: The control levers and steering on some radio controlled transmitters have small notches

can travel through

shock absorber’s cylinder. That

limited travel speed controls

On

the chassis has toe-out.

and

a

piston inside the shock absorber that has holes de-

signed to limit

left

distance between the centerline of

and the

tire

width at the front

nitro engine) igniting the fuel.

tires,

chassis, the rear wheels

to provide a few degrees

PISTON: The portion of an internal combustion engine that is driven down by the explosive charge from the spark plug (or glow plug in a radio control car’s

and

apart than the inner edges at the

that are designed to provide a tactile feedback so

know how far to look down

and dampens the action

of the springs.

you’re

moving the

at transmitter.

stick

you

without the need

Commonly found on

the

less-expensive two-channel transmitters.

PUSH: See Understeer. RIDE

TRIM LEVERS: Most transmitters have small levers near the steering wheel and throttle trigger that are used to make fine adjustments of the steering and throttle re-

HEIGHT: The distance of the chassis from the

ground.

measured after bouncing the car several and shock absorbers return the the normal position.

It is

Some

times so the springs

sponses that will remain in

chassis to

low you to program these adjustments so you can reuse them the next time you drive that particular car.

ROLL CENTER: The imaginary point or centerline where the wheels pivot inw’ard as the suspension moves up and

TRUGGY: The medium-size

down during heavy cornering

cles

loads.

size it

of the

will

real car.

For example,

if

be 1/12 the size of the real

model

is

carries the

1/12 scale

the real car had a model would have an

radio control off-road vehi-

Adjusting the suspension so each wheel

proper amount of weight.

UNDERSTEER

12 = 8.00) wheelbase.

(SEE

ALSO OVERSTEER): When

springs filled

cylinders inside the coil

on most radio control

a car loses

traction in a corner with the front wheels sliding first so

the car slides off the racing line nose

SHOCK ABSORBERS: The

al-

car. If

96-inch wheelbase, the 1/12 scale 8-inch (96

a

transmitters

with buggy chassis and pickup truck-style bodies.

TWEAKING:

SCALE: The proportion of the model compared to the

effect.

cars.

The

cylinder

with fluid and a piston moves up and

cornering, the car

first.

Also,

when

said to understeer if additional

needed to turn the wheels more sharply around the desired also sometimes referred to as push.

steering input

is

down

is

is

into the turn to keep the car tracking

through fluid as the suspension is compressed and reThe piston and its rod are connected to the suspension and the cylinder is connected to the chas-

curve. It

is

leased.

sis.

When

the

tire hits a

bump

the piston

is

WHEELBASE: This

forced to

ters

189

is

the distance between the exact cen-

of the front and rear wheels on the chassis.

7

39

1

INDEX 1

9T models,

Academy,

1

1

CVEC, 1 27 AF0421

02

7

92

Amezuca, 143

Travis, 132,

Anti-dive,

75

Mini-Z, 31, 33, 34,

Goodreau,

37,

63

Bender CNC, 42

Drifting,

Braking, 28, 149

Drivers’ platform,

37 78,

184 Drooping, 68 1

Byrne, Pat, 85, 151

Internet simulator,

Camber, 73, 74 Carburetor, 124 Caster, 74

132, 148

20A

1

158, 159

88

1

8,

Losi, see

Fall

LRP

74,

discharger, 88

Team

International

Hodapp, Gregg, 132, 138 Hodge, Todd, 89

APS

Horizon, 7

Megatech, 1

Nitro EDS, 120

Mayfield, Ryan, 132,

133

Model

23

7, 31,

1 1

Losi

88

Pulsar,

Magma

1,

120 Baga 5B Buggy, 52, 55 Dash series, 33 Micro RS4 series, 34

Piranha and ICE, 88

Racing,

Lexan bodies, painting,

1

Triton,

HPI Racing,

82

DuraTrax, 31

R/C

148

Horton, Russ,

Dumont, Brad,

163, 164, 167

Virtual

175

132, 139,

1

82

1

Hobbytown USA

143

Busenbery, Aaron, 182

6,

40

Monster, 41

7

24

Classic race,

Adam,

Drake,

28, 54,

Optic

Hobbico

171

James R., 7 Batteries, 87-89

10, 157,

1

Hitec, 17,

Barr,

Brockman, Chadd, 23,

Steve, 7

Hensel, Jason,

spectrum

Dirt track, building, 170,

Astro-Flight 110D, 88

1

Graupner,

22

1

23, 24, 101, 126

Associated

Giga Crusher DF, 55

68

modulation (DSM),

Team

Kyosho, 31

6EXA, 19 Gearing, 96

Digital

Anti-squat, 75

Helios,

Ride Height gauge,

Differentials,

Anti-roll bars, 71

1

Futaba, 17, 24, 92

Droop Gauge, 67

Cylinder head,

Associated, see

power,

125, 126

Velox XT, 53 Airrronics, 17, 23, 24,

Propo EX-10 24

Fuel-burning engine air filter,

.

1

Super

Rectifier

969

Brain

Pro,

88

Mohr Racing camber gauge, 72

Monster

33

trucks,

Motor brushes, 101 Motors

Cavalieri, Ryan,

132

Dynamometer, 101

Pro 4, 34, 71, 75,

Brushless,

1

03,

1

04

Chassis, 61-81,

84

Easton,

76, 80, 81

Modified,

1

02,

1

03

Colorado Crawlers, 182 Commutator, 1 04 Computerized transmitters,

Controls, radio

1

9,

20

vs.

remote, 8 Cornering,

1

50, 151

Corrally, 31 Corrally,

RDC, 34

Cost, 8, 9

Course, defining, 175

Crawlerstore.com, 33,

42

Billy,

132, 138,

RSR4 RT3

140, 143 Electric

12,

motor power, 95-107

Savage monster, 64

Racing, 36

(ESC), 24, 25, 104 Fail-safe control,

Fischer, Billy,

Flextek

RC

1

1

33-35

(International

36, 53

27

Inferno,

suspension

arms, 64,

29

Francis, Matt, 132,

Frequencies, 20-24

143

1

73

MP-7.5 buggy, 62

24 XP9303, 19 Jumps, 136, 137 KO, 17, 24, 92 JR, 17,

190

31

IFMAR

Indoor tracks,

32

MRC,

Great Power

2

1 1

Rebuildable, 102

Hurdy, 14 Federation of Model Car Racing), 32, 34,

Electronic speed control

Engine seizures,

Evo, 59

series,

Velox XT, 53

Mugen, 31 MRX-4, 53

MTX-3 ProSpec, 126

New

Era Models,

1

Nitro fuel, 114, 115

Nitro-powered cars,

47-59

53,

Breaking

in,

110-112

NN

33

chassis,

Nomadio, 1 4, 24, 101, 126 Novak Smart Tray and 88 Novam, 22 Flatline,

Racers), 9, 32-34,

TLC-1, 42

Tower,

36, 53, 84, 99,

TRF415 MS, 34

Tracks

101-103, 114, 124, 159, 169

TX2 Clod

Off-Road Nationals, 132, 135, 138, 140,

84, 139

143, 180

10TC4, 28 Factory

O’Bannon, Andrew, 7 OFNA, 31, 122

Rock crawlers, 33, 144 Rodriguez, Dante, 179

Factory

Oversteer, 80

Rollout, 97,

Pactra Acryl Racing

RPM camber gauge, 72 RPM toe-in gauge, 78

Factory

Sarator, Reggie, 66

44

Paved track, building,

174 Polk’s,

17

Tracker Porting,

III,

19

122

Set-up sheets, 63

84

Shock control, 70 Simple Green, 90 158

Racer’s Edge, 54,

Racing

line,

152-154

Radio control system,

24-27 Radio control transmitters,

1

7-1 9

RC Dyno Systems, 14

SHO

Buggy, 51

Team

,

125

Wolverine, 54

Sound, 1 24 Spektrum, 14, 22-24, 101, 126 Starter boxes, Starting,

Starts,

1

151, 167

142

Clodbuster, 33, 42

7,

TGIO-Mk.1, 65, 69 TG10-Mk.2, 58

143 Understeer, 80

Urban, Mike and Sam, 45, 167 Racing,

1 1

Discharger, 88, 89 Virtual

R C Racing, 148

148 West Mountain Radio

Virtual RC,

computerized battery analyzer

XXX-4 Buggy, 39 XXX-T Sport Truggy, 84

(CBA), 89

Orion,

CRFV6, 120

Wheelbase, 81

Whoops, 136, 137 Wrecks,

1

55

Tebo, Jared, 143

Xray, 31

Thundertech Racing, 42 Tires, 64, 84-87

T1FK, 34 Yokomo, 31

Toe

(in/out),

Toolkit,

191

Truhe, Mike, 96, 132,

SSS-4, 66

Team 1 1

disorientation, 141

(Remotely

29

1

MS2, 38

54

Suspension, 64

Operated Auto

1ST, 64,

Steering, 64, 73

Tamiya, 31 45, 85,

39

Mini-T, 32

1 1

Right-at-you

parts,

Sportmaxx, 52

T-Maxx, 52, 54, 64 Trinity tire warmers, 85

Venom

JRX-S, 34, 97

push button,

,

Losi, 31, 39, 84,

Hop-up

100, 101

Ride Height, 69

ROAR

E-Maxx, 33, 64

89, 93, 157

Slipper clutch drives,

110

RDLogic, 31

Traxxas, 27, 31, 52, 122

RC10L, 27 RC1 2-series, 34 RC18B, 32, 37 RC1 8T Factory Team Kit, 37 TC3, 116, 117 TC4, 34

Powerslides, 133 ,

176, 178, 184

Team RC3,

Scale,

Serpent Mega, 53

Race diary, 89, 90

131, 171, 172, 175,

Revo, 64

1

7,

19, 21, 83, 119,

S-Maxx, 52

Power Racing, 31 Proline, 31

Team

129

Schumacher, 31, 84 Mi2, 34

Ports, polished, 121,

177-179 RC Madness,

Scadden, Reggie, 38, 39 Schultz, Lee, 9

21

1

109, 170, 171, 175,

Team

RC12L4, 98 105-107

39

3,

179

NitroTC3-i-, 56, 57,

Sartor, Neal, 38,

1

Rat Raceway, 47-49,

RC102L4, 86

98

Mohr Raceway,

152, 173, 175, 178,

Associated, 31,

Robbers, Jesse, 96, 135

159

33

XB-series,

Team

31, 89, 96, 102,

7

21, 50, 110, 120,

O.S. Engines, 53, 122

Finish, 158,

Buster, 33,

42

1

90

76-78

MR4TC, 34 Rayspeed Exceed, 89

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