I have read about the diminishing returns in torque from CR increases. That makes sense, but I also wonder how it could possibly fit into the 'whole picture' of matching parts. Like Jim said- depends on the other parts.

I have 0 experience with race gas territory compression ratios but I suspect that if increases give diminshing returns then the primary reason for a 15:1 cr in a race setup would be to maximize the performance of a wild cam with lots of overlap.

So if your CR is low for what your cam wants maybe your gains could be greater?

I'm only guessing- I'd love to hear from someone that actually knows.