I just got new shoes and alignment and have a track day tomorrow. I have a Ruf RTurbo with a new set of 19 inch Michelin PS2s. Alignment is set at -.75 degress front/-1.75 degrees rear. I have some track experience, but am not an advanced driver by any means (and don't intend to try to drive like one). It's 100 miles or so to the track, so by the time I get there the tires should have close to 200 miles on them. Here is what I plan on doing, but all suggested changes warmly welcomed.

I plan on shooting for 38/42-3 hot, as long as the increase in temperature from cold is less than 10 pounds. My reasoning is based on 40 pounds hot being optimal for street tires, wanting to have a F/R differential so I get some understeer, and my belief that the front pressure on a TT has more of an impact on handling than the rear. OTOH, I know that the overinflation slope is steeper than the underinflation slope, so I don't want the rears to get to far above the optimum pressure. I will also take it easy the first time out to make sure the tires have a chance to cycle.

I have both a digital pressure gauge and the onboard SmartTire system, which gives average temperature readings inside each tire, but no pyrometer. Ambient temperature tomorrow is supposed to be 71 degrees at 9am, rising to 85 degrees in mid-afternoon. Is there a "hot" temperature range I should be shooting for with these tires?

 

I run 265/35x18 front and 315/30x18 rear Michelin PS2's on my 993 TT and the optimal pressure hot is 32 psi front hot and 35-36 psi rear hot. These are the pressures most everyone uses for Michelin DOT's on the track.

 

Michelin PS2's = i run 35 front 40 rear, 18inch stock rims, at watkins.