What are the major diffrences in pistons for type r's in usdm and jdm?

 

anyone?

 

Japanese spec pistons are higher compression.

someone correct me if I'm wrong, jdm gsr pistons are the same compression as usdm type r. I have been told, not entirely sure though.

 

All pistons are numbered differently from one engine to another. In some cases like a 2nd gen jdm b16, a p30 piston is used bring up to 10.4:1 which is .2 higher than the version found in a usdm version, or a B18C type r is 11.0:1 as oposed to the 10.6:1 found in a usdm one.

Basically, more of the oversea's engines come with slightly higher compression because higher octane fuel is available.

Thats about it.