all other factors being the same, and assuming the motor breathes well enough (I/H/E, manifold & headwork), what would the power differences be between 10:1 & 13:1 CR? the only reason I ask is that there seems to be only a slight gain going from 10:1 to 11:1 (type S) pistons and I just was wondering what the potential is from increased compression

 

I thought it was like 10 hp per raised cr point.

 

I've read the same thing - about +5% power for every point of compression raised.

Andrew