Join Date: Nov 2001
Location: state of confusion
As a general rule, mounting any given size tire on rims at the narrow end of the range results in turn-in response that's slightly 'softer', and steering precision that isn't quite as good as with widths out toward the wide end of the rim width range. Some people will notice this more than others, and I'm sure that there are some who'd never notice it at all.
Not trying to spend too much of your money, but I do have to wonder why you'd start out picking wheels as narrow as 9" for a dedicated track toy where there are no class rules limiting this dimension like there is in autocrossing. Unless 17" tires are easier to find than 18's, why not something like 18x10's instead, which would take 275/35's (or possibly 285/35's) still keeping to about the same OD as the 245/45-17 OE tires but with less sidewall height and cornering flexibility?
Mine: '08 GT, 5MT, black/light graphite, un-Fstock (DD, occasional track day)
Wife's: '10 Legacy 2.5GT (DD, six-speed manual)
Spare:'01 20AE Maxima, 5MT (also my bad weather alternate)
Various Loose Parts: '79 Malibu