Its the same regardless of fuel really, all that the fuel does is change what constitutes high or low cr in the first place.
Originally Posted by Bosch-Man
...a high comp engine will make more bhp per psi over a lo comp though...i know we are limited by the fuel...
That sweeping statement is incorrect in some instances.
At lower RPM, the volumetric effiency of the engine is too high and you will have to retard the timing massively to stop det if you go for high cr on a big boost engine, and that loses you more power than the hi cr gains you.
Its the same for an N/A engine, 13:1 compression is PERFECT for power at high rpm, but it means no bottom end torque cause the ignition needs to be as retarded as the average skyline owners opinions on CR
