yeah man staying factory to the R will definately give you an all around great feel. If you want to be able to drive daily and hit the track every now and again. Keep what you got on there stock. But if your talking about hitting the track daily and this is a straight race car then get some...
remap and upgrade your fuel system. I also do my fuel soon into doing mods because whats the use in all the mods if your not supplying enough juice. Granted basic mods, exhaust, intake, manifold don't require anymore fuel that factory its best in my opionion to get it out of the way.
well I would definately recommend stiffer springs it helps with body roll which is going to help the car stay level and true. Lowering it also assists with this. Tein makes a good set of springs and they are not too expensive for what you get.