I was wondering if anybody had used pr4s (ls pistons) in a b18c or b16 to lower compression for boost? I did a search and couldnt find anything. I just wanted some feedback.

 

this would work but id say get forged pistons because cast pistons break

 

not sure about a b18c, but i know ls pistons in a b16 drop the compression ridiculously low, like around 8:1 or some ----, so in a b18c, it may be around 8.3-8.5:1, which is still pretty damn low. if you just want to drop the comp., just get a thicker head gasket.

 

I used a compression calculator which I know is not 100% acurate but it calculated about 9.1-9.3:1 compression with a b18c1 and pr4s.