The Newsletter of Encore Music - About Legends Cars

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Nov 2, 2013 (3 years and 11 months ago)

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International Legendscars 2561 South 1560 West Woods Cross, Utah 84087 © Legendscars 2002

Phone (801) 295
-
3741 Fax (
801) 296
-
6442 e
-
mail
-
Info@Legendscars.com

web
-
www.Legendscars.com

The Legend






UNDERSTANDING THE LE
GENDSCAR?


Wheelbase


All cars must compete with a 73" wheelbase plus/minus 1/4 inch on either side (72 3/4" to 73 1/4").


The

width
of the car may not exceed 60 inches and the car must roll freely through a 60" wide by 48" high opening.


The
horizontal rear end offset is measured between the rear frame rails and the inside edge of the brake drum as the
car sits without the driv
er in the car.


There must be a minimum of six inches between these two points.


Most
cars only achieve about 1/2" of difference between the left and right side.


Shocks


In the year 2001, INEX has chosen to switch from the Carrera Shocks to the Bilstien

Shocks exclusively for the
Legends Series, and were mandated no later than July 1, 2001.


These shocks are Mono (single) tube shocks
means. There must be no dents in the body or the piston will not move in the tube.


Shocks may be turned upside down and/
or the upper end of the rear shock may be mounted on either the inside
or outside of the frame.


Shock bumpers are permitted.


Changing or altering the fluid inside the shock is illegal,
and will result in a six
-
month suspension for both the car owner and
driver.


Springs


All Legends Cars must use a 10" or smaller length spring. Any spring weight combination and aftermarket
springs are acceptable. Only one spring per shock, and no spring rubbers are allowed. Minimum ride height at
the lowest point of the f
rame rails is 3 1/2".




Pinion Angle


Use more downward angle for short tracks (more bite). Less downward angle for long tracks (for higher speed).


Also use less angle on dirt tracks to leave more room for travel between the rear of the driveline and fr
ame cross
member when going through bumps.


Basic Setup Information


Finding out how your going to setup your race car in any class of racing is a big challenge when just getting
started.


The car comes from the dealer with a basic set
-
up that gets you clo
se. Dealers have a book called the
Horney town cookbook that goes in to more detail. Also the book
'Dwarf Car Technology'

(#S225) by Steve
Smith is full of good information that is easily understood through his style of explanation.




All this information

combines to gives you a foundation to work from.


Developing your base setup is derived from
a range of allowable adjustments that can be applied to your car, controlled by physical tolerances that cannot
be exceeded without major performance loss The fol
lowing will give you a competitive starting point, you can
then fine tune the combination to work best for you.


Actual car setup is as diverse as the drivers themselves,
and is always a subject for debate.


There are three area's you'll work with from tra
ck to track they are 1. 'Ride
Height' on each corner, 2. 'Tire Pressure', and 3.'Spring Rate' on each shock.


The other adjustments are Caster,
The Newsletter of Legendscars

V
OLUME
3

ISSUE

3

OCTOBER,

2002



Newsletter Technical Issue!


Camber and Toe
-
Out.


It's helpful to remember this order on these adjustments.


If you adjust Caster, it will
a
ffect Camber and Toe
-
Out.


If you adjust Camber, it will affect Toe
-
Out only.


Toe
-
Out can be adjusted without
affecting either.




For paved oval track, these cars like a lot of right front wheel negative camber to keep the front end from pushing
in the t
urns.


Your caster setting will affect how easily the car turns left.


A good starting point for caster will be
Left Front (LF) pos+ 3 degrees. Right Front (RF) pos+ 2 degrees.


A rule of thumb is a 'one degree split' between

sides with a left bias.


For c
amber, start with LF pos+ 2 1/2 degrees, RF neg
-

4 1/2 degrees.


It is helpful to have

some good front end setup equipment (at least a camber/caster gauge).


Adding camber will affect your overall
width, so check that you can pass within the 60" width limi
t.


Your toe
-
out should be a least 1/16", with a
maximum of about a 1/2" for most tracks.


The spring rates on each corner of the car is difficult to define for an individual driver, and affects many of the
factors you will be monitoring such as individua
l wheel weight when the car is scaled, ride height, and how the
car reacts and feels under race conditions.


A good procedure to follow is to start by knowing what percentage of

weight each corner of the car is carrying against the overall weight of the ca
r full of fuel.


You will need to acquire
(beg, borrow or steal) a set of
Computer scales

to find this out, but it is worth all the trouble.


At this point it is
important to say, "Document Everything You Do To The Car!"


Find a
Chassis Set
-
up Sheet

and us
e it every
time you set
-
up or make changes to the car.


It will be nice to have once you find that sweet spot, and makes
your performance much more consistent from track to track.


You want to note the cross weight, left side bias,
and rear bias.


One meth
od is to set
-
up without the driver in the car to dial it in, then to note the final effect with
the driver in the car.


Although their will be a change, usually in the range of one
percent in each of these three areas, the driver weight is a fairly constan
t factor you
can estimate while achieving the final setting.


Measure cross weight by the
percentage of the RF and LR weight combined.


This is usually the higher number of

the two cross percentages.


According to this rating method, a higher percentage of

cross weight will eventually cause a
push

in the corner; a lower percentage will
cause the car to be
loose
.


Different Legends Car chassis styles (Coupe and
Sedan) will require different overall percentages to yield a balanced feel, but most
should fall i
n the range between 51% to 60% cross weight for best performance.


Adding a stiffer spring to one corner of the car or screwing the coil
-
over nut in
towards the spring will increase the weight load carried by that corner, which in turn
increases the overal
l weight percentage for the corners being measured. Adjust for
your car to eliminate understeer (push) or overseer (loose).


The left side bias can
be improved by adding lead weight to the left side of the chassis.


By the rule book, you can not exceed 52%

left side bias.


This helps to stabilize the car in the turn by reacting against the centrifugal force of the left hand
turn trying to lift the chassis, causing the left side tires to loose traction. The design of these cars and the
amount of lead weight
you can actually fit on the car should yield a range of left side weight bias between 49%
and 52%.


Rear bias is also improved by adding weight, again not to exceed 52% rear bias by rule.


This
improves overall rear traction.


Finding a balance on where t
o place the weight is the challenge, and should
probably be applied as fine tuning after you get a comfortable setup on the car without it.






Here is a basic starting setup. This is for a paved oval race track, and drivers can run it almost anywhere.


S
pring Rates (lbs.)

LF
-

200

RF
-

240




LR
-

180

RR
-

160



Tire Pressure (psi)

LF
-

17

RF
-

27




LR
-

12

RR
-

37



Ride Height

LF
-

3 3/4"

RF
-

4"





LR
-

3 7/8"

RR
-

4"





We have a

Quick Fix Guide
' you can use to fine tu
ne for your needs thereafter.




One last thing that should be mentioned is the squaring of the rearend, and the offset adjustment using the
'panhard bar'.


Set the wheelbase up initially so that when you check your wheelbase length with the standard
Lege
nds ('go, no go' gauge), set your length to 73" which is the middle of the variable (72 3/4" to 73 1/4") half
inch of play.

Then check each side of the rear end housing from the front cross
-
member and shock tower to the
front face of the rear end axle tub
es close to where the frame passes under them.


You can do this by hanging a
weighted string off of these two points on each side of the car.


If the rear end is square from the front cross
member, your front wheels will be square as well.


It is good to b
e aware of Rear Roll Steer, and possibly
compensate for it if necessary to keep the car from being too loose in the turns.


The right side of the car will
squat more than the left side going though a turn, creating 'Rear Roll Oversteer'.


To offset this ef
fect and keep
the car from becoming loose as you corner to the left, you want to (shorten) adjust the right side in slightly to
compensate for the trailing arm extending the wheelbase on that side of the car as it squats going through the
corner.


The effe
ct is cause by the trailing arm sitting at a slightly downward angle when the car is going
straight, but as you turn and the right rear of the car squats down, the trailing arm connection at the rear end
travels upward in an arc becoming more parallel with

the chassis. This creates a longer distance between the
point 'A'

connection at the frame and
point 'B'

connection of the trailing arm on the rear end and pushing

the right side of the rear end back.


This adjustment can
be used for fine tuning, but being

too far out of adjustment

can affect handling dramatically.



Remember also, if you change your pinion angle, you
should check for changes in your wheelbase and rear end

offset.


The panhard bars on these cars are hard
mounted, with no vertical adjustment

for tuning the rear roll center. But you can get a slight effect in a similar
fashion just by raising, or lowering the rear ride height evenly (try to get a 10.125 ground height at the center of
the mounting bolt).


Details on this type of fine tuning can

be extracted from the pages of the book
'Dwarf Car
Technology'

(#S225) by Steve Smith.


Legends dealers also can offer the HorneyTown Cookbook by H.L.
Hupperich Jr. These books are a very good investment for setting up cars. Rear end offset is measured be
tween
the outside of the rear frame rails and the inside edge of the brake drum as the car sits without the driver in the
car.


There must be a minimum of six (6) inches between these two points.


Set this adjustment as close as
possible to 6" on the left
rear, to maximize your left side bias.


This information is just a part of what affects the
handling on these Legendscars and is intended to help you get you started.


The Legends Engines


Legends are now competing in the United States with three engines
in the class.

The YAMAHA FJ1200, XJR1200, Blitz XJR1250 (Sealed). A YAMAHA FJ1200/XJR1200 from other countries
(Canada, England) or an FJ1100 may only be used if it meets all the specifications of the current U.S. model as
delivered through 600 Racing Inc.

They are air
-
cooled 4
-
stroke engines running on pump gasoline.


Yamaha
recommends the use of 89 octane
-
unleaded gasolines.


Gasoline additives are closely scrutinized.


Such
substances as oxygen or nitrogen bearing agents (including propylene oxide) are
prohibited.


By the rule book,
the engine must remain a factory
-
stock engine. The compression ratio cannot exceed 10.0:1.


The cranking
compression must be below 180 p.s.i. at any time (hot or cold) on at least 3 cylinders with the ignition off and
thrott
le wide open.

A controversial new rule is going to be in effect for 2002, where all the spark plugs will now
be removed to test cranking compression, instead of removing the one spark plug on the tested cylinder.


This
will ultimately cause a higher crank
ing compression than previously attained by the old method of testing due to
a higher cranking speed.


A slotted cam sprocket can be installed for tuning, and advancing the intake timing
will increase the compression.



The valve lash can be used as a tun
ing device.

The valves are adjusted by bucket and shim.


The best starting
point would be, .006 intake, and .008 exhaust. You can reduce the clearance by .002 to give the engine more
top end power, or increase the clearance .002 for low end power.


The c
ylinder bore cannot exceed 77.57mm or 3.054" (maximum .022" overbore from stock).


The Blitz sealed
engines cannot be overhauled by anyone other than an authorized 600Racing authorized rebuilder.


The carburetors are Mikuni BS36 x 4 constant vacuum.


Re
-
j
etting is permitted.


The engines are mounted 90
degrees counter to the way Yamaha designed them to be cooled by airflow.


The #3 cyl. Is a common problem
area on these engines due to heat caused by the restricted air flow to the back cylinders.


Have the
carbs tuned
to keep #3 and #4 from running lean.


Venting fenders and hoods, while staying within rules, is recommended.


Oil coolers are also recommended to counteract the high temperatures. There are several good units available
from your Dealer. A 12 vd
c fan is also advisable to enhance cooling.


The ignition is 12v battery powered, inductive, digital, magnetically triggered. Recommended spark plugs are the
NGK DP8EA
-
9 or ND X24EP
-
U9 for US models.


The sequential gearbox in the engine is a constant mesh

5
-
speed, wet clutch.

Gear Ratio:

1st


40/14 (2.857)

2nd


36/18 (2.000)

3rd


33/21 (1.571)

4th


31/24 (1.291

5th


29/26 (1.115)


There are wide varieties of quality conventional or synthetic motor oils.


These engines run hot, and it is
recommend
ed that the oil be changed every 1 to 2 outings under these extreme conditions.


Many motorcycle
racers recommend the Torco MPZ Synthetic 20
-
50 Racing Oil.


An exceptional synthetic oil is the

Red
-
line High
Performance Synthetic Engine Oil.




Asphalt


Mo
st drivers will agree that your tires should be camber cut for best performance on asphalt (oval).


The
technique is to add camber to the tire and increase the amount of tread coming in contact with the track surface
during cornering. This is done by shavi
ng rubber off the right side of the tread to increase camber angle.


Check
with your Legends dealer for recommendations on tire preparation for local tracks. If they can't provide a service
themselves International Legends has a very good tire machine and
offers great service and delivery.


Make sure
your rims are straight and in good condition before mounting tires and shaving.

Once a tire is cut on a rim, you
want to keep it mounted for the duration of the tires use. If a rim is damaged and needs to be r
eplaced, it is
recommended that the tire be cut again to true it after mounting on the new rim for best balance.


Dirt

For dirt racing you want fresh tires, and all the tread.


Take advantage of natural differences in tire circumference
to improve stagger
percentage.


Tire pressures used will usually be around the 8
-
15 lbs. range.


Road

For road racing, the tires are cut down evenly to 7/16" (faster) to 9/16" tread depth to reduce tread flex for best
performance.

Shaving does cut the life of the tire but t
he performance gain is worth it.


Dirt in front wheel bearings

Dirt in wheel bearings is non
-
metallic road grit or brake dust that has entered the bearing because of a worn
seal, or it could be metallic particles that were left in the bearing housing the l
ast time you had the rotors turned.


Good wheel bearing maintenance is to clean and inspect the bearings before each race as well as brake shoes
or pads. The rear brakes on Legendscars require continual adjustment as they tend to back off and will cause a
push entering the corner (due to too much front brake). You should also inspect the rotors at this time as well. If

the bearing shows signs of wear, replace it with a new inner and outer race. Pack each bearing with a good
quality high pressure grease and

install new seals.


Warning: I have noticed that some after
-
market rotors with an integral bearing housing are probably being
sourced from China and have very poor machined bearing seats for outer bearing races. These bearing seats can

be rough, tapered,

out of round and can lack concentricity between the inner and outer seats. Race car rotors
must be replaced with good quality rotors to prevent premature bearing failure and wheel wobble.


I have also noticed the seal surface of some wheel spindles aren't

smooth enough, and the inboard seals are
being chewed up in as little as 50 laps. If you find this to be the case then polish the seal surface on the spindle
with fine emery paper until it has a bright appearance (the smoother the better). Replace the sea
l, and be sure to

lubricate the rubbing surface of the seal with bearing grease at assembly.

Brake Notes


Modern racecars need good brakes. Good brakes will allow you to drive faster. High performance brakes have
improved tremendously over the years with F
ormula 1 and GT leading the way using the latest carbon/carbon
brake technology. The Formula One world champion, Mika Hakkinen, once was quoted saying “The most
important thing in a sports car in not the engine but the brakes”.


Rotor Notes:


*

There are m
any types of rotors available for racing applications such as steel, cast iron, carbon/sic,
carbon/carbon to name a few. Rotors can be solid, vented, drilled, or have slots on the friction surface.

*

Cast iron rotors are the most common and readily availa
ble for many applications. Cast Iron rotors
should not operate at a bulk temperature over 610 C and above 3000 rpm.

*

Carbon/carbon composite rotors perform well at high temperatures, much lighter (less rotating weight
and unsprung weight) and are very ex
pensive. Carbon is typically used in F1, GT, and is showing up more in
drag racing, motorcycle and Champ cars (depending on regulations).

*

Drilled rotors offer improved bite but are more prone to cracking more so than grooved or solid discs.
Rotors shoul
d be discarded of cracks emanate from the mounting holes, slots, ID or OD. If in doubt, change the
rotors to be safe. It is not worth the risk of a rotor failure to save a few bucks

*

A grooved disc improves cleaning of pad surfaces and provides more cons
istent brake performance and
longer life than cross
-
drilled rotors.

*

Runout: With the rotors on the racecar, the runout should be less than 0.005”


Brake Pad Notes:


*

Brake pads typically wear more on their leading edges. High end multi
-
piston racing c
alipers have
smaller pistons on the front going to larger pistons on the back of the caliper to even out brake pad wear.

*

Pad break
-
in or bedding: always break
-
in according to the manufactures recommendations. They spend
hours testing on brake dynamomete
rs to develop procedures for bedding the pads. It is not the best practice to
race with new out of the box pads.


Fluid Notes:


*

Use a DOT 4 with the highest boiling temperature that is available. Some race fluids have a boiling
temperature of over 600 F
.

*

Limit the exposure to the atmosphere. Brake fluid will absorb water which will lower the boiling point.
With moisture in the fluid the boiling temperature can be reduced to the 212

240 F range.

*

It is a good practice to flush the brake system with
fresh fluid after a race that required hard braking.
Once the brake fluid has been very hot or near the boiling point, the boiling point can be lowered.


Bleeding Notes:


If time permits, a great way to bleed is gravity bleeding.


*

Open all 4 calipers w
ith master cylinder full

*

Use clear tubes off each bleeder into a drain pan on each caliper

*

Bleeders should should be pointed up for this to work properly

*

Watch for bubbles in the tubes. Once there are no more bubbles, close the bleeders tight.


H
eat Notes:


*

Brakes convert kinetic energy to heat. KE=1/2 MV2, or the amount of heat generated increases by the
square of the increase of speed (V). The faster you go the more heat the brakes will generate.

*

Cast rotors should not operate at a bulk tem
perature over 610 C

*

Caliper temperatures should be kept well within the working range of the brake fluid to prevent fluid
vaporization and loss of braking.

*

Peak fluid temperatures should not exceed 240 C or operate over 200c for over an hour. Either
case the
seals will most likely need replacing.

*

Stainless is a good choice for pistons due to slower heat transfer than mild steels.

*

For optimum performance, operate at the correct brake temperature (refer to manufacture
recommendations). All discs s
hould operate at similar temperatures front/back and side to side (balance).

*

Use temperature paints or stickers to monitor or investigate rotor, pad or caliper temperatures. When
testing for brake temperatures it is important to complete several laps in

succession (say 10 laps) at race
conditions.

*

Try to keep most of the air flow directed up the discs vents. It is important not to overcool, but keep
enough air flow to keep the temperatures stable within the working range.


Brake Suppliers:


*

Brembo

*

AP Racing

*

Wilwood

*

Legendscar Dealers



Safety Check


Always perform a complete safety check on every bolt and nut on your car. Pay attention to fuel lines,
air filters, throttle cable and linkage, steering box, brake lines, wheel studs and nuts, s
hifter linkage,
battery clamps and mounting, seat belts, spring adjusters, shock travel, bumper bolts and nerf bolts,
all body attachments, electrical connections, driveshaft bolts, fuel tank fittings, helmet, gloves and
driving suit. Many good races are l
ost due to some simple thing coming off. Last but not least, wash
and degrease your car. Look good and have a safe racing season in a great sport.



Testing is Important


Most drivers will have recommended toe, caster, and camber settings. They arrived at
these numbers through
exhaustive testing. Yet the goals of the driving styles of these drivers were probably different from yours. And
what works best at one race track may be off the mark at another. So the "proper" settings are best determined
by you
-
it
all boils down to testing and experimentation. You cannot get enough seat time


From the Staff of International Legendscars


International Legendscars 2561 South 1560 West Woods Cross, Utah 84087 © Legendscars 2002

Phone (801) 295
-
3741 Fax (
801) 296
-
6442 e
-
mail
-
Info@Legendscars.com

web
-
www.Legendscars.com