Is there a benefit to running an 18" wheel over a 17" wheel as far as driving dynamics or weight transfer? I'm trying to decide on a wheel setup for the track and I'm thinking the RPF1 17-8.5 or NTO3M 18*9.5. Obviously the rpf1 are a lot lighter and I was thinking that would be better. Not using a big brake kit or anything- running DBA5000 with race pads. Just curious on the logic behind running a bigger wheel is. Not talking about wider but overall diameter.

 

17 x 9.5'' with 255 40's RA-1 would be nice. Stretching the tire over the larger wheel will give you a larger contact patch and is recommended by various suspension tuners for maximum grip. Oh, the RPF-1's are the best bang for your buck rims when it comes to light/strong, and yes the come in 17x9.5. To run that rim you may have to roll the fenders

 

The supposed advantages of running a larger diameter wheel is to firm up the side wall (essentially by making it smaller) and allowing for less slip angle between the rim and the ground. While this will always be the case with larger rim with smaller sidewall, much of that performance gain can be quickly canceled out and resulting in a worse performing rim/ tire if the rim is excessively heavy resulting in a significant increase in unsprung/ rotational inertia. Hope some of that helps

 

Absolutely- thanks for the info. My mind is made up.