My advice would be to ask fellow racers at the track. You'll find that even if you set your pressures at the start you may need to adjust them when you come in after each session depending on track temperature, weather temperature and tyre temperature.
Id take oil and coolant with you too :)
You may find you may shred your tyres or cook your brakes so bare this in mind if your driving home with it :)
i speak from experience as my brother is a race driver :)