T1-R's will hold up quite well. I've been running the T1-S on track and a buddy of mine just did an event with me at
www.roadatlanta.com with the T1-R's on his 350z. They held up well. They are about the best street tire you can get for the track. In order to get better, you would really need to start looking at race tires like the Toyo RA-1.