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LEARN TO RACE AND WIN
BY FRANK MUNROE
AKA DR.DWARF
Winning starts at home. You cannot win at the track if your car is not
prepared to win. Preparation is the key to standing in the winners circle on
Saturday night.
You constantly hear drivers talking about other drivers that win on a
regular basis. You hear,
"He has more money than God"
"He has a monster motor"
"He has special tires made"
"He cheats"
"His car is illegal"
Well, you get the picture! In most cases, none of the above is true. These
drivers have done their homework in the garage before they even loaded the
car on the trailer, (they even took the car off the trailer from the last
race!).
If you race and want to be a winner, you must put in the time at home to
prepare the car. I spend about 12 hours a week on my car, and that is if I
didn't hit anything and 16 or more hours if I did! In our form of racing,
this can be tough. It is a hobby and a lot of racers don't have this kind of
extra time to put in during the week. But you should realize if you only put
in enough time to wash the car during the week, you're probably not going to
win on a regular basis. Whatever problems you had last week, will still be
there.
A good pit person can be a lifesaver! He (or she) can help you during the
week and cut your load in half.
*Plan at least 2 nights a week that you and your crew will work on the car.
*Have a routine that you do every week.
*Make a checklist and use it.
The off season is a perfect time to make your car a real winner. Your first
step is to take your car apart. Even though you think everything is ok, if
you raced last season, your car should be thoroughly checked out.
*Mark all your parts as you take them off so you will know where they go
when you put them back on.
* Take off all your tires and wheels. . Check your tires: are they worn or
cracked? In many cases, the tires look good everywhere but the edge is
rounded off. This tire can be reversed on the wheel so it will be usable
without having to replace it. A couple of edges may not seem that important
to you but the edges dig and grip the track when you go into the corner or
getting on the gas coming off the turn. A good tire can make a big
difference, especially on a dry track. I believe tires should be replaced at
the start of the season. Use your old tires for spares or practice.
Used tires are always easy to sell and can off-set the cost of new tires
*Check your rims: Are they bent or are the holes for the lug nuts worn? If
so, you need to replace them. This is a safety issue. A bent wheel can make
the tire hop when you reach top speeds which will cause a loss of traction.
Another thing to check when replacing wheels is the offset of the wheel. Do
you have the correct offsets to achieve maximum car width your rules allow?
You know the saying, Wider is Better? Make sure you have a couple of extra
tires on wheels so you can change your offset to fit changing track
conditions.
hint: Start the night on a heavy dirt track, with the car at maximum width,
front and back. If the track dries out later in the night, have a wheel and
tire ready so you can suck the right rear in. This tire should be a
smaller tire in circumference than the one you started with so it will
lesson the stagger when you suck it in.
* Remove the rear end from the car, take both axles out and the third
member. Check the housing for straightens. One clue to a bent housing is
when you pull the axles and they are hard to get out. If you think it's
bent, have it checked by the builder. He probably has a jig to check and
straighten the rear end housing. Next, check the axles and splines to see if
they are straight. If they are twisted, the axle is going to break. Replace
it. If the splines look good, have the axle checked to make sure it runs
true. A bent axle will throw your rear end out of balance and cause tire
shake, which will in turn cause traction loss. On your third member, check
for cracks in the welds, and the back lash in the gears. You can lose or
gain horsepower there. If you have a spool, check the splines for wear. Now
is also a good time to check the gear ratio's. Make sure you have the right
gear ratio to achieve the RPM's that deliver the most horsepower for your
motor. 300
or 400 RPM's can make the difference between winning or running second. Once
you have checked the third member, the axles and the housing and are
satisfied that it is race ready, reinstall the third member (This is a good
time to check the axle seals) and slide the axles in. They should slide in
smoothly and turn smoothly in the rear end.
*Check your master cylinder, brake calipers, brake pads and rotors.
Worn brake pads, warped or pitted rotors, & stuck caliper pistons can cause
handling problems on the track. Brakes are not just to stop the car, they do
a whole lot more. Properly working brakes can make a big difference on how
your car handles when you press on your brake pedal! Check your brake pads
for wear...are they wearing straight? If not, check your brake rotor for
uneven wear. If your pads are worn more on one end than the other, your
brake bracket on the rear end may be bent. With the brake installed over the
rotor on the rear end, check the side play between the pads and the rotor.
Check it at the top and the bottom of the caliper. If the distance is
different, you may need to straighten your brake bracket. Now is a good time
to have your brake rotors turned at a Brake Shop. Rotors can glaze over and
cause braking problems. Clean your brake calipers and check for leaky piston
seals. Replace if necessary. When reinstalling your brakes, replace your
brake fluid. Once the calipers and rotors are reinstalled on the rear end,
turn the axles making sure you have no binds and the pads run free when the
brakes are released. Don't forget to bleed your brakes. Do this a couple of
times and again after the brakes have gotten hot at the track.
*Remove your trailing arms from the car. Measure the arms from the center of
the right rod end to the center of the left rod end. Write this measurement
on the trailing arm. This will come in handy when reinstalling the arms. I
recommend replacing the trailing arms and rod ends at this time, especially
if you race on the dirt. If you plan on reusing any of the rod ends or
trailing arms, check for free play in the threads on the rods and the ball
on the rod ends. If you find any, replace it. Don't risk wrecking your car
for a $6.00 rod end or a $10.00 trailing arm. When installing new trailing
arms, use the measurement you took from the old arms as a starting point.
Lubricate all rod ends before installation.
* Remove all four shocks from the car. (This section refers to gas, steel
bodied shocks) Take the springs and coil over kits off the shock. Check for
leaks around the shock shaft at the seal. If it leaks, it's history! Replace
it. Here is a simple test: Clamp the rod end of the shock to a vise with the
shaft up. Pump the shock up and down 3 or 4 times. With the shock fully
extended, leave it sit for 20-30 minutes. Then press down on the shaft. If
it drops fast, the shock is done. Don't use it, replace it. If your
association allows aluminum shocks, they can be rebuilt. Once you have
determined your shock condition and replaced the bad ones, check the coil
springs. Check your local speed shop to see if they have a spring checker.
They can check your spring rate. If your spring has become weak, replace it
with a new spring. Once your springs are ready to reinstall, check your coil
over kits, looking for cracks or bad thread. Replace as needed. Install the
coil over kits and springs on shocks and make sure you zip tie your coil
over cone to the spring. Reinstall the shocks on the car. Make sure the
shock and the spring doesn't hit any part of the car. Move the
suspension through it's motions and see that there are no binds. Any time
the shock or the spring binds or hits any other parts of the car, this can
effect the shock dampening and the
spring rate. Another thing to watch for is where the shock bolts to the car.
Make sure the shock rod end ball has side to side movement. If it's tight,
install a hime spacer. This is also a good time to lubricate the shock rod
ends.
*A-Arms
Most dwarf cars have some kind of tubular upper and lower A arms. The
tubular A arms usually have rod ends and ball joints to attach them to the
chassis and spindles. These rod ends and ball joints should be checked for
wear and straightness. If the rod ends are worn or bent, replace them. Check
the ball joint shaft to make sure it is not bent. Move the ball joint
through it's motions to check for binds. You should have a smooth motion. If
not, it needs to be replaced.
*Steering
Check your steering shaft and steering u joints. They should have little or
no play when moved side to side. Too much play can cause a delay in the
steering action which can cause the driver to oversteer or steer back and
forth to compensate. The steering motion should be smooth from all the way
right to left. Check your steering box. If your car has a chain and sprocket
steering quickener, check the chain and gears for wear. Worn gears or chains
can cause the same steering problems as mentioned with the U joints. There
is also the possibility the chain could break, leaving the driver with no
steering control on the track, leading to a wrecked race car.
If your car is a rack and pinion steering unit, it should be cleaned and
checked. Before removing the rack from the car, turn the steering wheel
right to left. Does the rack feel smooth? If not, check to see why. The rack
should steer smoothly with no binds or rough spots. Once the rack turns
smooth with no binds, remove it from the car and clean it. Check the shaft
for rust or chips in the teeth. Clean and relubricate it. If you have an
aftermarket rack check with the manufacturer for lubrication
recommendations. Don't forget to check the steering wheel quick disconnect.
The part is often overlooked and can cause big problems if it fails.
Spindles and Hubs:
Remove the hubs from the spindles, then remove the bearings and clean them.
Spin the bearing in your hand and make sure the bearing turns free and has
no rough spots. If the bearing feels rough, replace it. Grease the bearings
and reinstall into the hubs. On your spindles, look for bent shafts or
cracked welds and check the bracket that attaches the steering to the
spindle. This bracket may not seem important, but it can be the key to a
well handling race car. This bracket has a big affect on the bump steer and
ackerman steering. There are a lot of opinions on this topic and I could
talk about that all day long, but let's just say that the slight angle
changes on the steering bracket can really impact how your car is handling.
Motors:
Hopefully, while you had your car apart, you sent your motor to get
freshened. I said freshened, not enlarged! One of the biggest misconceptions
I hear people say is that you need a big motor to win. With race track for
Dwarf's mostly being 1/4 mile or smaller, in most cases, too much power will
just get you in trouble. The key to going fast is to have usable horse
power. If you paid attention to the article and worked on your race car,
checking every part to make sure things are as free as possible and not
robbing horse power, you may feel like you got a new motor come race day. A
properly handling car with a good driver will outperform a big motor in a
poor handling car, anyday! Spend your money on the right components that
will enhance your current motor and chassis. Before you ever consider buying
a new motor, make sure your have a good set of carburetors, and a good
header and cooling system. Good carbs can add horse power to your current
motor. A tuned head and a good cooling system can make it all come together.
If your motor runs hot, it will cost you horse power. Now that the car and
the motor are taken care of, let's set up the chassis to go racing....
Set Up:
Now that the car is on the ground, find a level spot in your shop to perform
the set up.The first step is to set the air pressure on the tires. Depending
on what tire your club uses, that will determine what the tire pressure
should be. The wheel can also effect the tire pressure. If you run bead lock
rims, the tire pressure can usually be run lower than a non-bead lock rim.
Since most of the country has gone to a Hoosier Tire rule with a 7" or 8"
rim, with no bead lock allowed, I will concentrate on that tire/wheel
combination. If your club runs something different, adjust your tire
pressure accordingly.
Dirt Track: Right front: 11 lbs. Left front: 10 lbs. Right rear: 11 lbs.
Left rear: 10 lbs.
Asphalt Tires: Right front: 19 lbs. Left front: 16 lbs. Right rear: 18 lbs.
Left rear: 16 lbs.
Just a couple of things to consider when setting pressure...Rough tracks may
require higher tire pressure to keep the tire from coming off the wheel. The
type of air you use out of a air compressor can effect tire pressure. If you
use air of out of a compressor, the tire pressure will increase during the
race. This increase depends on how hot the tires get. Normal increase is
between 2-6 pounds. Nitrogen in the tires instead of air will not be
effected by the heat and very little tire pressure change will occur. Keep
in mind that 1 lb. of pressure can change the way a car handles.
Now that the pressure is set, square the rear end to the chassis. Some
manufacturers build in squaring marks on the frame. If your chassis is
equipped with these marks, use them to square the rear end. If not, then
take a measurement from the middle of the lower A arm to the center of the
rear end. Set both sides of the car at 73" wheel base. Once the rear end is
square, take a measurement from the center of the rear end to the center of
the lower ball joint. Moving only the lower A arm, set the wheel base at
73". If you have trouble achieving this due to non-adjustable lower A arms
and have to move the rear end, move it evenly on both sides. This should at
least keep the rear end square. If you have trouble getting a square
measurement, no matter what you do, something is probably bent. Check your A
arms and rear end for straightness again. Keeping the car square is very
important, especially when it comes to sorting out handling problems later.
Now set the side to side measurement for the rear end. Start out with even
measurements.
Set the Ride Height: Check with the manufacturer of your chassis to get
height recommendations. Usually the chassis was built to work at a certain
height with the other suspension. Most dwarf cars are designed to run
between 5" to 6 1/2". The chassis's that I build and run have been designed
to run a frame height of:
Dirt: left front: 6" right front: 6 1/8" left rear: 5 3/4" right rear: 5 7/8
Asphalt: left front: 5 3/4" right front: 6" left rear: 5 1/2" right rear: 5
3/4"
Now that the chassis is square and the frame heights are set, it is time for
the caster and camber on the front end. To do this, you will need a
caster/camber gauge. If you don't have one, borrow one. If you can't borrow
one, buy one. This is a very important tool to have. Checking the
caster/camber on a regular basis will be the difference between running up
front and falling behind. Check with your chassis manufacturer for setup
recommendations. Here are some recommended caster/camber settings:
CASTER:
Dirt track: left front: +3.0 degrees right front: +3.5 dg.
Asphalt: left front: +3.0 degrees right front: +4.0 dg
CAMBER:
Dirt track: left front: +1.0 degrees right front: -3.0 dg
Asphalt: left front: +0.5 degrees right front: -2.5 dg
Your next step is to set the toe out. This may vary from car to car
depending on how well your front end was designed. The less bump steer your
car has, the less toe out you will need. A basic rule of thumb is the
smaller and tighter the track is, the more toe out you will need. So keep in
mind, the toe out will need to be changed to accommodate different size
tracks. Smaller tracks, more toe out, bigger tracks, less toe out. Start out
with 1/8" to 1/4" tow out. This will work on both dirt and asphalt. Pay
close attention to tire wear on the front tires at the inside and outside
edges. This will give you an idea if you need more or less toe out.
Scale the car: Scales are an important tool to have. If your budget allows,
buy a set of scales. they can cost from $1000.00 and up. If this kind of
cost is out of the question, don't worry. Go in with a couple of buddies or
get your club to buy a set of scales. Also, check with your local speed shop
or one of the late model teams in your area. they will usually offer chassis
set up and have a set of electronic scales. They may charge you for the
service, but it is well worth it. The first thing to consider when putting
the car on the scales is total weight. Most clubs have a minimum weight rule
of 1000 pounds. Check your local rule. Weigh the car with and without the
driver. How close are you to the minimum weight? If you must add weight,
start with the weight on the left side of the car. Try to keep the weight
between the wheel base of the car and behind the driver. Now with the driver
in the car, record
weights.
Suggested Weights:
Dirt tracks:
cross weight- 48.5% to 51.0%
Asphalt tracks: cross weight: 51.0% to 52.5%
left side: 51.5% to 52.0%left side: 54.0% to 57.0% rear weight.
These weights are weights that work well on M&M chassis but may not be
exactly what you want. Check with your chassis manufacturer. Don't be afraid
to try new ideas. That's how you find out what works.
Good luck with these ideas and If you have any questions, e-mail them to Dr.
Dwarf located at WWW.dwarfworld.com.
Frank Munroe
aka Dr. Dwarf
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