I don't see a-lot of sliding in the GT3 races I've watched on TV.(with the exception of the Acura NSX on worn tires at the end of last year's Spa race.) Certainly not in the Imsa GTD races. You may find some quibble with lack of tire wear, but the slicks run by most GT3 variants are very grippy. Touring cars, which tend to use a smaller wheel/tire do have some built in slide, just don't recall seeing a GT3 behaving badly. finally, you should have the Nissan GT500 R in your stable. Give that a try and let us know if that is the feeling you are looking for.