Originally Posted by
Fiesta_Jed
If there were two evo engines one with a 7.5:cr and the other with 8.5:1
would there be any difference to the boost threshold, lag and power/torque after the low comp engine had its map adjusted?
(both engines have identical specs turbo, boost, cams, rod ratio ect)
Its actually very hard to generalise as to which would be better as obviously the cams are going to suit one CR better than the other, as is the rod ratio etc.
Engines are very much a package, and there isnt one answer that works on all specs.
With regards to boost threshold, not likely to be effected greatly either way as its more about the volume of air going through the turbo than what CR the engine it came from was.
With regards to power and torque, anywhere that the engine was taking lots of timing on 7.5:1 its likely to make more power on 8.5:1, and vice versa