I didn't mess with tire pressures too much. I started with 36F/38R and then moved down after a couple of runs and ended up at 34F/34R. The tires were rolling over just fine and the car was rotating okay. I didn't want to mess things up since the car was performing alright.
The OK Region does post the PAX times for all runs, but I like how they split the classes up too. With the PAX multiplier, all should be equal when it is factored in, but creating separate PAX classes gives you something to shoot for.