Out here there's a 1966 Lotus Elan and a Dodge Viper that run faster than some of the prepared and modified classes. Then there are all the c4's, c5's and a couple turbo Miatas. I wish the SCCA wasn't so boost-adjustment unfriendly.
I thought about running 265/45-16's on 8.5's. I just checked the faq and it has 255's listed as the widest front tires. Hmmm. You should search :)