Hey, i just finished putting pr3 pistons in my b18b so now compression is at 10.8 vs. the stock 9.2. What kinda gain from that you think? I also have a jdm itr header, iceman cold air intake, 2.5 inch exhaust and a 75 shot of zex.

 

I'd guess around 10 hp difference. Maybe more. Depends upon your fuel tuning. I'd say to bring your ZEX down to the 55 shot to be safe though.