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Hi Everyone, I found this quick cheat sheet for suspension and tire pressures... Although this is for BFG R1 Slicks which I run on the track, it gives a very very good idea of how to change settings in your car and how to datalog stuff via tire temp.... Its a great article....

http://www.bfgoodrichtires.com/asset...ne_2.26.07.pdf

Tire Pressures
Determining ideal tire pressures means finding the optimum balance between grip, vertical
stiffness and lateral stiffness from the tire. Let’s talk about hot pressures first.
In developing the BFGoodrich g-Force R1, we have seen that optimum hot pressures should
be in the 34-48 psi range. Vehicle balance can be adjusted somewhat by varying hot pressures.
Based on our testing, hot pressure changes tend to affect handling as follows:
» Increasing front tire pressure reduces turn-in understeer.
» Reducing front tire pressure increases turn-in understeer.
» Increasing rear tire pressure adds rear cornering grip, increasing understeer.
» Decreasing rear tire pressure allows car to rotate more on corner entry.
A logical tuning approach would be to target pressures toward the middle of the recommended
range and adjust target hot pressures based on vehicle, track conditions and your driving style.
The cold pressure required to get the desired hot pressure is dependent on variables such as
humidity level inside the tire (especially when inflated with compressed air rather than nitrogen),
vehicle setup, track layout, ambient and track temperatures, and your driving style.
If you have track experience with your vehicle, you probably have a good idea how much pressure
increase you’ll see. In general, set cold pressures 5-7 psi below target hot pressures. When in
doubt, err on the high side since lowering pressure is quicker and easier than raising it. Plus,
overestimating pressure increase can lead to running on underinflated tires — a safety concern.
For autocross applications, you’ll need to run significantly higher cold pressures than
you would on the track. The short autocross format means tires see less heat and less time for
pressure increase. Therefore, cold pressures must be set much closer to target hot pressures.



Adjustments Decrease Understeer Decrease Oversteer
Front Tire Pressure Higher Lower
Rear Tire Pressure Lower Higher
Front Tire Section Larger Smaller
Rear Tire Section Smaller Larger
Front Wheel Camber More Negative More Positive
Rear Wheel Camber More Positive More Negative
Front Wheel Toe Toward Toe-out Toward Toe-in
Rear Wheel Toe Toward Toe-in Toward Toe-out
Front Wheel Caster More Positive More Negative
Front Springs Soften Stiffen
Rear Springs Stiffen Soften
Front Anti-sway Bar Soften (Thinner) Stiffen (Thicker)
Rear Anti-sway Bar Stiffen (Thicker) Soften (Thinner)
Weight Distribution More Rearward More Forward

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