I recently dropped my compression on my JDM H22A motor from a stock 10.6:1 to a 9.1:1. Now I see that the Type S pistons are 11.0:1 and the engine has 20 more horsepower. So when I drop my compression by 1.5 how much power and torque would you expect me to lose. Keep in mind its been bored to 87.25mm which doesn't really matter, I have a complete Crower valvetrain, Eagle rods, ARP studs and mains. Hybrid CAI, full N1 Exhaust, Hondata S200 w/ P28. Numbers please. Just appx. est.

 

I'd estimate around 15hp

 

Any reasons to your est. or just a guess.

 

I heard somewhere that for every point (1.0) you raise your compression you gain 5% more power, providing you keep everything else the same.

So... I'd guess you'll have 92.5% of what you were making before.

 

Alright so I'll still be making 200 hp at the flywheel is what we've basically come to. With the modifications I have that is. I'm going turbo in March, I just didn't want to drive a turd around all winter. I get the car back Friday, I'm just a little nervous. We'll leave the thread at that, unless anybody has information to contradict these answers you guys gave. Thanks, Rob.