im using bridgestone potenza re55s type SR and TT on autocross events. highly recomended, good grip on high speed cornering.
federal 595 for my daily drive. good grip but not as sticky as the re55s, but performs well in the wets.
This was last June 26-27, 2009 at SM parking lot (Mall in Cebu City, Philippines). organized by Kartzone. my ep82 managed 2nd runner up on the novice modified category.
http://www.youtube.com/watch?v=2jSOkQjwmGc&feature=channel