Originally Posted by autoXitrSoCal
...I think I will just try the 205 azenis's I have on my 15x7 street setup for the first event.
I think that's very a very smart thing to do.
Later on when I go with R-s, what sizes do you recommend?
The widest reasonable size I've seen in R comps is 225-45-15. However, it's available only on the expensive Hoosiers as far as I know. Going to 225-50-15 is cheaper but there are other sacrifices involved, and I've noticed that Honda Challenge racers eschew 225-50-15 as undesirable.
If you go with 225-45-15 you will have to be careful of your wheel offset. Hoosiers in that size are really quite wide.
A reasonable alternative that many of us prefer (assuming it's track days and not all out racing) is 205-50-15 on 15x7 or 15x7.5 wheels on offsets in the +35 to +38 range.
I have a set of 205-50-15 Victoracers on SSR Type C 15x7.5 +38 and a set of 205-50-15 RA-1 on Kosei 15x7 +38, and they both fit perfectly on a car with a reasonable ride height.
It looks like the Victoracers will be a little stickier than the RA-1, but at the cost of an evidently vastly reduced tyre life.