Scaling your race car is arguably one the most
important practices that you can do to increase your chance of
visiting victory lane. Proper chassis set up requires that the weight
balance is set correctly for the car, driver and track conditions. In
order to achieve proper and repeatable weight balance a quality set
of corner weight scales will need to be obtained
Before you begin the scaling
process you should make sure that the car is race ready. Fluid levels
need to be topped up, stagger & tyre pressures are set, ride heights
adjusted, Caster adjusted, Camber set, rear end square and the toe
checked. You will also need to see if your total weight is within the
rules and the front to rear balance is where you and your chassis
builder want it. Emphasis should be placed on being race ready before
you begin the final scaling procedure as all of these factors will
have an effect on the end result.
Now that you are ready for
your final scaling procedure you will need to find a level area to
weigh the car. Most garage floors vary by quite a bit. Spend a few
minutes with a good level and straight edge and mark four spots on
the floor that you can use each time you want to scale the car. Make
sure that you mark the floor to match up with your wheel base and
track width.
Should the floor have low
spots you can use simple shims to make all four scale pads level or
utilize some leveling trays to speed up the job. Mark the shims or
trays with LF, RF, LR, RR so that you can quickly repeat the process
each and every week. Consistency is the goal when scaling so weighing
the car in the same spot each and every week will improve your
chances of having a great handling car.
Now that you have a level
surface you can roll the car into position. Set the scale pads next
to the appropriate tire and hook up the cables. Make sure that the
cables are plugged into the correct pad and turn the scales on. Check
that there is no weight on the scale pads and press the zero button.
The control box should now read zero and you are ready to place the
pads under the car.
Jack up one side at a time
and slide the pads under the tires. Place the car in gear or use a
stop to keep the car on the scales. Verify that the anti roll bar is
disconnected or completely neutral with plenty of slop. At this
point, give the rear of the car a firm settle by placing your knee on
the rear bumper. Then do the same at the front.
After settling the front and
rear, grab the roll bar and shake the car several times. Try to let
go right in the middle. By settling the car and shaking the roof bar
you are helping to insure that the shocks are not hanging up and that
you have worked out any small binds in the suspension points. Try to
do the settling procedure consistently as this will help you obtain
repeatable results. Settle the car after each time you raise it with
a jack or make an adjustment.
You can now record your
wheel weights, partial weights and percentages. Check that the front
to rear balance is correct and that the left side and total are where
they need to be. If not then move the lead ballast to the appropriate
spot until you are happy. Readjust the ride heights if you have to
move ballast around.
Now you can check the cross
weight. If you want to add cross weight put a turn in the right front
and left rear and take a turn out of the left front and right rear.
On non coil over cars you may need to go two turns on the rear for
every one turn on the front. By adjusting all four corners you will
help maintain your ride heights.
Now you can set the anti
roll bar. With the car still on the scales you can see exactly how
much pre-load you are putting on the bar. Record your final settings
and you are ready to go.
