Which of these tire setups will provide more cornering grip - all else equal?

[Late__Apex]

225 R-Comp or 255 Star Spec (or similar)?

[rex_racer]

Depends on what type of R comp and under what use conditions, track or autox. Then comes track temperature and conditions. Why not just do a wider R comp?

[Late__Apex]

Road race use.

The two options are "scoring neutral" in NASA. A larger r-comp means I probably have to move up a class which I don't want.

[4ceFed4]

It's really condition dependent, like rex said. Unless you have 9"+ wide wheels to mount the 255s to, your contact patch isn't going to be the full 255. I run 225 star specs when it's cold and/or wet, and 265 f/225 r r-comps when it's warm.

[Ryan E.]

I'd run the r-comps, they can take more heat and are usually lighter with a stiffer sidewall.

[enginerd]

Id run the r-comps (hoosier, BFG, or V710). They will have equal or better grip, take hard track abuse/heat , and they will weigh less. Problem would be the tire wear.