I have to agree with Claudius.

For the sake of this theoretical discussion we must assume two things: 1) A neutral handling setup and 2) Properly inflated tires at the start.

To verify correct initial pressures: equal temp readings measured with pyrometer at inside, center, and outside of tread immediately following hot lap, before tires have had an opportunity to cool...no cool down lap. This must be done for each session and track as changing ambient temperatures and track surfaces will require different settings.

Now increasing pressures in either front or rear will reduce the effective contact patch. This can be verified again with the pyrometer, center temp will be higher than the edges. This means less effective contact patch and changes as small as .5 lbs make a difference. All pressure adjustments are intended to increase or reduce contact patch, that's why we do it

Lowereing rear pressures will also reduce the effective contact patch: higher edge temps and lower center temp. The difference here will be the sidewall's capability to mitigate the transition to oversteer by absorbing/dampening the initial lateral load thereby requiring additional energy (lateral load) to break free. This will translate into soft or mushy rear handling characteristics.

It is much easier to induce oversteer in properly inflated tires by increasing rear pressures which still decreases effective contact patch but eliminates any tendency for the sidewall to absorb or dampen the transition. This will translate to sharp and predictable rear handling characteristics.

The only differences between this theoretical neutral handling car and a real one are whether or not the front tires can maintain sufficient friction to remain free of understeer. This is where a very complicated compromise must be determined and will have to factor in the individual circuit (number, radii, and types of turns, length of race/tire wear, pit strategy, etc...) to establish the balance which will deliver the optimal performance results. It's a science and cannot be oversimplified.

 

I checked the air pressure in my tires today and found that they had 57lbs in every tire! I think that is the "shipping pressure" and should have been checked by the dealer before delivery. I put them all to 44lbs and it feels much better! You all might want to check your tire pressures...

 

44 is still a bit on the high side

 

it isn't an evo but on my RWD car i keep the rear pressure about 2 pounds less then the front, not for oversteer but for better grip at the drag strip.

 

Maybe your tire guage is bad. I dunno for me, on my integra's z-rated tires i used 2 tire gauges. The first one said 36 all around, and the second one which i just bought said 40 all around(Checked it when it was cold). My friend tried his own tire gauge and his said like 45(Hot). I dunno wtf im supposed to do. All i know is that my tires are suppose to be at 38 or below because i took my car to a service station and the guy who specializes in tires said it should be there

If i put my pressure lower than 38, i can feel how heavy my wheels are. Its a hell of a difference.

How am i suppose to know if i have good tire gauge?

 

I would concur.

Not to beat the poor horse, but by your posts above this would give you considerable understeer, would it not?

 

This is TireRacks guide on Air Pressure for competition onhttp://www.tirerack.com/tires/tiretech/competition/racepres.htm This may well help us all. Thanks to everyone for their contribution

David