I just finished another weekend at Grattan. I came this time with Bridgestone Potenza RE-71R tires upsized to 235/40 R19 and 265/35 R19 on Momo Rims that are about 8 pounds lighter than OEM. I also have Girodisk 2-piece rotors on the front. These tires were much more track friendly that the OEM tires I used three weeks ago, and I enjoyed driving on them much more. That said, this tire setup pushes the OEM suspension beyond it's limits. I have Eibach Front/Rear sway bars and a Mando controller, but stock springs.
There's a couple parts of the track that are high speed with curves, where the car compresses to the side as you accelerate through them. It's a bit unnerving because the weight transfer is building as you accelerate, and the tires griping hard, but you don't get a sense of their limits like other parts of the track. Saturday evening, I set my front sway bars to hard, and it did help, but reality is, the car needs to be lowered by a good inch to get the center of gravity down, and it needs firmer springs - probably firmer than anything offered by the aftermarket, outside of coilovers. I would really prefer using the OEM shocks with firmer springs, because the adjustability of the shocks is amazing. There was a lot of debate on the Stinger forum as to whether or not they adjust for just compression or rebound due to there only being one electrical control, but after reading Mando's unique shock patent and playing around with the settings, it clearly is both - which is something you can only get on K&W coilovers.
I have a lot of video to download and render in Harry's Lap Timer. I'm glad I have the equipment to record, but there's a lot of tech setup before each session. Everything has to be properly connected and checked before you start, so I would start prepping 15 minutes before my session. My best time was 1:39. The guy next to me had a custom Porsche Cayman S, with a full cage, dedicated track tires, and 12 years of experience. He was the fastest guy there today, and he was doing about 1:23 on an older set of tires. It's amazing how fast the top group gets around that track.