Tyre pressures...for track time

[cully]

all i can say is go out and try them, dont stay out for too long or you will overheat them

exactly this
many short sessions are better than few longer with a roasting car and tyres

short sessions give you chance to rest the car, cool everything down,
make adjustments and gives yourself chance to get a drink and cool off,
it can also give yourself  some space from the knob-head that just cut you up on the track