Just back from June ECTA meet with feedback. Ran with 50psi cold in MT front runners in front and 40 cold in MT 275/60/15 Drag Radial Pros in back. Did not check air pressures on Saturday when it was cool, but on Sunday when it was hot, the fronts had risen to 60 and the rears to 45 coming off the track after a run. Ran an airdam that increased my top speed from 167 to 174. But, the airdam increased downforce and changed my dynamic alignment settings. Also found that the suspension is very active (too active). With the front end down from the airdam and splitter, the added nose down of braking made the car a little scary at the transition point and i found myself using the second turn-out most of the weekend, just so I could brake easier. Clearly I had bumpsteer from the toe-out induced by the nose dropping from downforce, further aggrevated by braking (I have road racing brakes). Spend Saturday afternoon cutting off the splitter and Sunday experimenting with different toe settings. Increasing toe helped A LOT in braking, but made the car more twitchy during the speed section of each run. On the last two runs, I dropped my air pressure down to 35 all the way around and ripped into a big headwind and ran 167. Car felt better, although my video shows more driver input at speed than my mind remembered. I think perhaps the softer tires allowed the tires to deflect instead of the suspension (maybe?). Lots to learn and lots of TnT to do next year. Will probably wait till June meet due to 2 daughters graduating next year. I have a couple of autocross/road course events to do this summer, so the toe is getting pulled back out. Then this winter, I'm going to zero camber, as much caster as I can get into it and DOUBLING the spring rate. Gonna make a variety of aero devices to try out in June. Will aim to stay in the 170mph range next year, but get the car handling before doing anything that would increase speed. Will plan to stay at the 35psi tire pressure as a starting point for next year. When surveying drivers at the meet, tire pressures were all over the map. Thanks everybody for all the encouragement and advice. Even though I started this thread with the specific intended goal of a tire pressure survey, it was super educational and I read every post and I really appreciate everybody's advice.