I start them cold at around 31.5 psi. After I come off the first session I chek them right away and then drop the pressure to 36psi hot. Repeat after every session and adjust as necessary. Hi tech guys will check tread temp across the surface of the tire but I mark the tires to see how much tread I am using to the shoulder. I try to keep the pressure right at the point wear the tire is rolling just to the edge of the tread where it meets the sidewall. This has worked well for me. Disclaimer: Lots of stuff goes into the right pressure including suspension setup, track, environmental, driving style, etc. That being said, the poor mans way I listed above should get you close. Works well enough for me as I am beating alot of C5/C6 guys and I am on the stock tires. Of course my mods and aggressive driving style don't hurt (anything but the tires and egos)!