I keep finding different answers, and the search button is'nt helping. I have a '99 B16A head that I want to put on a JDM B18C bottom end. My understanding is that the JDM GSR came with 10.6:1 compression. What would it be with my '99 Si B16A head on it? Very important because I'm running a Drag III turbo kit, but Im looking to pick up some more torque, and can get this low mile b18c for dirt cheap.

 

10.4:1. The b16a head has a slightly larger combustion chamber.

 

Any Idea of HP ratings with this combo?

 

It'll be right at or slightly higher than USDM GSR #s with stock cams and w/o the turbo. A .4 boost in compression is not a huge leap, and although the b16 head flows slightly better than a GSR head, the difference is marginal.

 

lol..nice avatar...