RogerT

For the experts, how do you see the correlation between understeering, oversteering, and tire air pressure front and rear?

I have my understanding of the concept, based on what I have read in related books, ect. but I sure hear alot to the contrary.

Please give your imput and supporting logic or material.

I find this fasinating.

Roger T

davidfarmer

personally, I find different tires react differently. You need tire temps to dial in the perfect alignment/pressure, then adding or removing pressure from there will reduce grip. However, some tires are more sensitive to others (Kumhos seem to work from 18psi to 38psi, while other tires need to be dialed in perfectly).

Keep it simple, dial them in based on temps, then add/subtract to reduce grip on the "stickier" end and balance tire wear. Remember, ultimate grip and tire wear don't always go hand in hand either......

Solofast

While more pressure at either end will reduce the slip angle there, and therefore change the understeer/oversteer relationship it is better to tune understeer and oversteer with roll stiffness and shocks.

Get the tires to work right, with the right pressure that they want and match that to the camber that they want and that is the best way to setup the car.

RogerT

I understand adjusting roll couple distribution with springs, sway bars, and shocks. The contraversy about air pressure is my question.

It certainly seems to be two schools of thought here.
Please jump in here. I'm taking notes.

Roger T

shifter77

There are many ways to adjust understeer/oversteer. I usually start with my adjustable shocks. If track at that day produces understeer, i will softer my front shock or stiifen the rear shock. Oversteer, i will do the opposite. if am still not happy i play with the tire pressures. Most important, make 1 CHANGE at a time. If you dont have adjustable shocks, alignment & tire pressure is the only choice for change.

C5 Hardtop

Check out this pdf from Michellin. While its content is highly geared towards their track tire, there is general information in there about tuning with air pressure which I think you may be interested in.

http://www.tirerack.com/tires/tirete...nd_Feeding.pdf