Open to the floor... I'm curious what people's impressions are of various R compounds as fitted to oem width 17" wheels for road courses - NOT autocross.

I've run Toyo RA-1 on my SpecMiata, and was very happy with them, but my preliminary research indicates 245/40 or 245/45 all around would be ideal. Toyo doesn't make a 245 RA-1 that I know of. I'm concerned the 255 would be too wide for the front wheels. I know people run 275 hoosiers for autocross, but my car is unlikely to see a cone course ever again - this is strictly for road courses.

Obviously, different mfr have different 'real' widths in a given size, so perhaps a 255 kumho would work well, but a 255 dunlop won't - I don't know.

So, if you would, list what tires you've run, the sizes you're running, and please list if you're running anything other than oem 17" wheels.

Also, I see TireRack is selling the Dunlop SP Race, which comes in a 245/40-17. Anyone run these? Are these even 'real' R compounds?

ahm

 

I have been running the 245/40/18 on Nismo wheels using the Toyo RA-1 tire, which for me is a DOT-R, not a slick. It has the grooving that allows it to be used to drive it on the street/highway legally to get you to the track. It is often used as a race rain tire as a full slick would obviously be unacceptable under rain/wet conditions.

Although you could drive it daily, you probably would only get about 5,000 miles on them, so it would be rather expensive. ON the track you can get four or five track days on a set, assuming four or five sessions of HPDE lapping on a 2.5 mile road course, with about ten laps per session. By using the 275/35/18 in the rear it provides a all around diameter of 25.3 inches on the wheel/tire set up. This is not for 17's, and I am using it on a G35, a car that is eight inches longer and 200 pounds heavier, so this is not exactly what you are looking for as information. But I have been very well satisfied with the Toyos, when speed balanced and the adjustable front camber arms adjusted to negative 4 degrees or a tickle more.

Hopefully someone here has the exact experience you are searching for, but this is pretty close start.

Good luck.

 

I've been using ra-1's for years. On the Z I have 275's on 17X9.5 wheels. I don't think you even want to put a 255 on the front let alone the 275. Toyo's web site says that it should be run on a 8.5 - 10" rim.

Here's the link to their page.
http://www.toyo.com/tires/tire_specsheet.cfm?id=1