Corner Balancing

Knocked out a corner balance on a track prepped 997S today.  The car was set up pretty good last year, but this year the owner decided to pull the supercharger off, and remove the A/C to make a lighter car, which of course messed up our weight distributions on the car.  Scales showed the car came in just under 3050lbs.

What is the purpose of corner balancing?

Corner balancing is the process of shifting the weight carried by each wheel to the most optimal values.  The result of having even weight distribution, is that on the track, the car will turn left the same as it will turn right.  With an uneven corner balance, you might find your self fighting left hand turns more so than right hand turns, or vis-versa.  Evening the cross weights out will even out the way the car handles through the turns.  Very important on the track.  The weight distribution is controlled/changed by raising or lowering the ride height of the car using suspension spring height.  With a track car running stiff springs, the weight carried by each wheel is affected by small changes in ride height.

The goal of a corner balance is to get the ratio of weight front to back the same on each side of the car.  When those ratios are the same, the cross balance weights are also equal!

There are a few mathematical equations to take into account, as well as a few important rules, all which need to be taken into account when corner balancing the cars.

For instance,

1.  Changing the weight at one corner of the vehicle will change the weight at the other 3 corners in one direction or another.

2.  You can’t shift weight between axles, or side to side.  IE, LF + RF will always be constant, just as LR + RR will always be constant.

3.  You can shift weights through diagonal measures.

With the race weight of the driver at 150lbs this year, our total weight to corner balance was 3195.  I didn’t get an initial shot of where I started, IIRC this picture came after the first minor adjustment.  As you can see, we have a 53.4% cross weight….not good.

Given this information, a few calculations later, my target weights became:

625LF, 590RF, 1017LR, 958RR

After a few hours of fiddling, the final weights were:

630LF, 583RF, 1014LR, 956RR.  Which is about a 50.1% cross balance.  Not too shabby.

Coilovers are what allow the easy ride height change.

And back on the ground…..