JDM GSR head on B18B block

P30 pistons = ?
P72 gsr pistons = ?
P73 usdm pistons= ?

What are the compression ratio using standard size pistons? Thanks.

 

i know someones gotta know... help me out guys.

 

http://www.c-speedracing.com/h...c.php

not the most accurate but it'll give you a close idea

 

That sites telling me Id have a higher compression running Pr3s over p73s is this correct?

 

so do we estimate up or down on the result on that calculator?

 

Yes you will have higher compression running B16 pistons over ITR pistons.

The estimation can be higher or lower. The only way to know for sure is measure your piston to deck height and cc your combustion chambers.