The tyre chalk is a good thing to do, that will tell you a lot about what your tyres are doing. I almost always do that.
The air tank we have is small so i try to have enough pressure in the tyres and only use the tank to tweek the pressure, or if you are at an open track event and you have let a lot of air out when they were really hot, when they cool down you might not have enough to go home, the other reason for the air tank.
The next autocross is a two day event, the first day is test and tune, the second day is the race. That should give me a good day to set the car up for the race.
For day to day street use, i run 35 psi all around.
