I am only autocrossing, not tracking. Also, wheel and tire width, camber, and surface also matter. I set my pressures based on what the outer shoulder is doing, working the tire to a little above the arrows on the shoulders with RE71's.
For what it's worth, my typical setup:
Wheels: 19x10.5
Tires: 285/35-19
Camber (F): -2.7 degrees
Pressures: 30F / 29R, +/- ~1psi
(Before every run, like DaveW mentioned...)
Reading the tire is always a good idea....
from AutoX event Sunday