Alright I have an OBD1 H22 motor in my 94 coupe and I have a serious decision to make. As some of you may know there is a company by the name of Mahle motorsports who assembles pistons that have a coating on the skirting to allow longer engine life on a boosted H22A engine. Since I want to turbo my car come March, i bought 10.1:1 comp pistons. Then, we looked at my cylinder walls, and boy were they bad. So, then some friends told me that since I now needed to get overbore pistons, I should go with the 9.1:1 comp 87.25mm bore pistons. Now the engine goes back together on Friday, and I'm wondering, should I sacrfice that power NA. The only reason is obviously for more boost. Stick with the 9.1:1 or get the overbore 10.1:1. By the way, stock comp on a JDM H22 is like 10.6:1.

 

Don't everybody respond at once now...

 

go with the 9:1 comp or 9.5:1 and get 87.5mm