We may earn a small commission from affiliate links and paid advertisements. Terms


Senior Member
What makes the compression ratio higher on the JDM H22. Is it just higher compression pistons or what. I'm not talking about the Type S with 220. Is the difference in HP in these engines just the pistons or is it something else. I khow its only about 10HP difference but does the compression ratio of teh pistons count for all of this? also if you had a USDM H22 with 190 horses could you just change the pistons to type S and gain the extra 30 HP?


WRX Sellout
The difference in the compression between the JDM and USDM base model Preludes is purely from different pistons.

The difference in power between the two engines is from pistons, cams, and a slightly better exhaust manifold.

The difference between base model Preludes and Type S Preludes looks like this: 11.1:1 compression ratio, more aggressive cams, and a ported-n-polished head and intake manifold. You'd need all of those things in order to make the 220 horses at the crank that the Prelude Type S makes.