You should probably check out Grand Prix Legends. Although i've never played it b/c im a panzy, oval track lover. I've heard great things about it from everyone here and it seems there are literally tons of mods that keep this game going and so on....This is the min/pref. specs taken from the official website
Minimum:
Windows 95/98, 166MHz Pentium, 32 mb Ram, Windows compatible video card with 2mb of memory, 2x-CD-ROM.
Preferred:
266MHz Pentium II, Rendition or 3DFx accelerator card, 64mb Ram, Windows 95/98 compatible sound, steering wheel and pedals.