I am going from the factory 15x6.5 wheels with 205/55/15 tires to a 17x7 wheel the thing is I really want to stick as close as I can to factory tire diameter wich is 24".
From formulas I found on the net I figured I needed a 215/40/17 tire size it seemed to be the closest at 23.9" but I recently realized that those formulas did not include the half inch wider wheel I know it doesnt make that much of a difference but I get a little particular as far as my 92 SI. So I was thinking 225/40/17 would be the right one to go with. Any opinions?
Also anyone have any input on what tires are the best? I have researched it and found mixed reveus about most low pro tires. Main problem being they are hard and some times imposoble to balance. noise and comfort mean nothing to me, grip and handling mean EVERTHING and price is a minor consern (I know you have to pay to play)

 

http://www.miata.net/garage/tirecalc.html

i think kumho MX's are right up your alley.