Hey all,

How good are these Sti 2.5l heads and cams :confused:

How much whp are they capable of :confused: before they start to restrict power.

Also ive seen few ppl pushing up to 400whp with stock Sti 2.5l motor w/ heads and cams but like to know the flowing limit of the heads :confused:

Lastly, would they be good option to get them heads port and polish :confused:



Thanks
Ken

man, these sti heads FLOW!ive made 420whp on them w/ aps sr55 now just finished rebuilding my,motor.you can make 500+ on stock heads guarenteed! the block may not hold up very long, the pistons are kinda weak, my buddy and i just put in a crawford s2 block. so hope that helps, you could blow your money on that upgraded valvetrain,but really its not neccessary. later,

k.c.

The USDM STI Heads flow about the same as the WRX heads. The higher lift cams help out with flow a bit.
Here is a way to look at it.

The following engines using the exact same variables, one engine utilizing ported heads and the other using unported heads.
Engine A unported heads= 350hp @18PSI

Engine B ported heads= 350hp @ 16PSI

Ported heads will give you more power easier, and shouldnt shift your power band to much... if they are correctly ported for your application and not overdone.