I was running about 35 up front and around 40ish for the rears....my rear tires have a shitty sidewall though, even at 40 they flex way more than what I have up front. I probably should've jacked the pressure up a little more...I noticed on the way home that any steering input would take awhile to reach the back of the car due to all the give from the sidewalls.

Optimum traction will probably be the lowest psi that doesn't cause the tires to roll over onto their sidewalls....if you have too much air in the tires you'll have a smaller contact patch than you should.

the tight left corner coming out of the first section of track probably caused people to spin because their oscillation from over-correcting finally exceeded what their suspension could handle. I spun once or twice there from using too much "feint" angle with a huge correction causing the car to snap around. On stock suspension it probably would've been a huge bastard because you have about 4 transitions worth of energy built up in your suspension by that point.