Dave, to answer your question differently, for tracking with your CTSC you need the 265 or 275 in the rears to put the power down. And if you go with such sizes in the back, you need at least 225-235 in the fronts. It's all about balance.
Hrant, I was thinking along the same lines. That the stock sizes are perfect for the engine and trans, brakes, etc. but as you go up in power... I now have a CTSC at around 350 whp and plan on going with Dave Dozier's setup of the twin aerochargers. He is running 400 and 440 depending on tune.
I also now have a stoptech BBK, and of course my made "infamous by my number of questions" KW competition with 1000/600 springs. So the engine, brakes, and suspension are no long stock and beyond what was.
Now I am doing this RSII group buy, and so I was ordering either 17x8 and 18x9 or 18x10 rears. That decision of rear width is a bit dictated by tire choice. To keep TCS ratio identical, with a 215/40, I'd need not a 275 or 265, but a 255 and the perfect wheel for that is the lighter 9" rear.
I haven't been to the track lately, want to do 2 events later. I'm not really at the skill level to need Hoosiers, or probably even R comps, (or probably any of the other shit I've bought lol), but I guess I just need to decide what to do.
Again to keep TCS perfect, if I go 235 front I would need to go 275 rear. What's the thing to do here? So many choices. What would you do? I Have my stock wheels too, but let's keep those out of the equation for now. Let's say I am going t just mount and balance track tires and street tires on the same wheels. Even if I used my stock ones for the track, the fronts aren't really wide enough for a 235. So I think it's really up to the advans to do all the street and track duty, which is fine. I can clean my stock wheels, have the slight curb rash fixed, and put them away in storage.