The dealer is currently working on my car, and told me I needed to replace all piston rings. I have a JDM B18CR w/JRSC. Now,the rep is telling me that I might as well change my pistons, and if I were to, he suggested that I get USDM ITR pistons because it has a lower compression and that it would be better for my setup. Would it make a huge difference if I were to get USDM or JDM? Was also looking at these spoon balanced oem pistons...but not sure if they would be any better. Thanks.

 

How much boost on the JRSC? There's really not much of a reason to lower compression on a SC motor unless you're going to up the boost.

 

Well, I did get the boost upgrade kit, which I think is around 8psi or so. Yeah, I didnt think that compression is a big factor either for a sc motor, but wanted to make sure before I purchase them.

 

I'm thinking the dealer is somewhat motivated to suggest USDM pistons by the fact that they are unable to order JDM pistons.

Honestly though it would probably be a good idea if the pistons are being replaced anyway. It'll increase your margin of error with detonation. It will lower your CR from about 11.1:1 to 10.6:1.

 

at 8psi, 10.6:1 would be just fine and safer.