Test-n-tune was yesterday. Due to a big turnout, I didn't get as many runs as I had hoped. I was able to work mostly with front tire pressures, settling on 42lbs with both the Rivals and the Z2s. I may try to bring the Rivals down another pound or two, as there was minimal scuffing at the edges.
I was running 45lbs in the rear and rotation was great. There were no really tight turns, but on a decreasing radius sweeper I kept clipping the inside cone. A tighter course may benefit from higher rear pressures.
It has been a few years since I competed, and I was surprised by how rusty I was. Nevertheless, the car was really good. As I suspected, fast transitions are the big challenge. This car leans a LOT. With the Rivals up front , there was a lot of rubbing when the car leans. It's not bad enough for me to not use the tires up front, but enough that I wouldn't recommend them without reservation.
After all was said and done, I was the fastest GS car, 14th time overall, and 4th pax out of 89 drivers. There was another FiST driver on oem tires who laid down his fastest time by accidentally leaving the traction control on. He was about a second behind me on the 36-40 second course.
By the way, a true limited slip would go a long way in this car, lots of wheel spin in the turns.