thinking about putting a ITR Head on my B18C1 , i have heard the compression ratio will be lower, does anyone know what it will be(with stock GSR pistons)? also is there any other special needs to do this besides using the ITR manifold, TB and ECU ?

 

I have heard that the GSR head will give roughly .2:1 higher compression over a PR3 (B16A/B18C5) head. So going the opposite way I'd say to take roughly that amount off. I'm sure someone will come on here and spout some exact numbers for ya. I won't as I don't think it will make much of a difference.

 

yep your right the gsr has a 41.6cc combustion chamber and the b16a/type r has 42.7cc. its the smaller cumbustion chamber make the higher compression.

 

JDM ITR pistons in a B18c1 yield 11.3:1

JDM ITR Pistons in a JDM B18c yield 11.1:1

Same block, different head.

 

so putting on a mugen head gasket should recover most of the loss in CR. Anyone know what kind of power gains this combo will give you over stock GSR?