cbuzzetti wrote:
Something to consider with the R1R test is that it sounds as if they were testing at an autocross.
If this is true then these tires may not be any good for road racing.
This looks like a tire that Speed World Challenge used a few years ago.
If this is the case we want to stay away from those they were terrible. (personal experience)
I've actually used street tires that are built for SCCA's ST class on the track all of last summer on my 924S with a full Spec suspension and a full interior and didn't suffer any issues. You won't see the peak grip of an RA-1 or an NT-01 but it is close and I didn't suffer any overheating issues even in the heat of the summer on a heavy car. I ran the 205/50/15 Dunlop Star Spec. The Hankook RS-3 is very similar to the Dunlop (even superior according to some in grip and heat tolerance) and comes in the 225/50/15 size. If people within the region are on this tire, it'll definitely produce fun, even racing and my Dunlops survived most of a season and didn't feel heat cycled out when I got the car race ready.
The Toyo R1R is probably too narrow and too sensitive to heat to run well over a long life. Also, the R1R has to be shaved to 4/32. The first 4/32 (so from 8/32 to 4/32) is a harder compound. The RE-11 is too expensive. The Kuhmo XS is bad in the rain. The Yokohama AD-08, Star Spec and RS-3 are very evenly matched, but the Yoko and Dunlop only come in 205/50/15.
Comparing the current crop of ST tires to the Toyo street tire used in World Challenge YEARS ago isn't a valid comparison.