Originally Posted by Geezer
For track use you'll want a dedicated race tire as they come shaved (shallower tread prevents the tire tread from ripping itself apart). They operate much better as they heat up (retain their grip). A street tire (even high performance ones) will get greasy much more quickly. There's a handful of ultra high performance summer tires tires that can be used for lapping with OK results but you risk the chance of chunking the tread. Size wise, some wider 15's or 16's (meaning new wheels as well) would actually be better for track use.
I'm interested in getting a set of rims and tires for some track use as well. My thought is to get a set of used rims (stock from somewhere), and add tires. Where do I find "track" tires that you mentioned?