Originally posted by dubster99
The Type R has a higher compression ratio, which under boost is more prone to detonation.
Exactly! The B18C or C5 has 10.6:1 cr and the B18C1 has 10:1 (which is still high for FI). You'd want to drop to 9.5:1 or 9:1 to be able to run a decent amount of boost - with the right rods of course.
That been said, it's a waste of about $1000 to get the C/C5 if you're just going to lower the compression as that, springs, retainers and cams is really all that it has over the C1.
Hope that explains a little more.
