Subaru WRX Forum

Subaru WRX Forum (
-   Cylinder Head & Short Block (
-   -   need a new motor (

isaacWRX2004 12-14-2008 07:04 PM

Can anyone tell me which motor is stronger an EJ20 or EJ25

newtothegame 12-14-2008 07:38 PM

The japanese versions are stronger. They come with some nicer internals over the USDM version. The EJ25 can and does produce more torque upon upgrading the car.

isaacWRX2004 12-14-2008 09:01 PM

So would I be able to drop an EJ25 into a 2004 wrx?

newtothegame 12-15-2008 12:38 AM

Yep, or you could do the hybrid build that has become a popular build with the pre 06 models. It has been done by a few members on here, search for it. A member named Chase did a parts break down, and a small write up.

mosc 12-15-2008 02:19 AM

[QUOTE=isaacWRX2004;211235]So would I be able to drop an EJ25 into a 2004 wrx?[/QUOTE]
No, the simplest way is not to drop in a whole motor but to build a hybrid (as newtothegame said). This means you keep your EJ205 heads, wiring harness, 16-bit ECU, etc. The only thing you change is the shortblock. Usually people get the EJ257 (from the STi, not the 06+ wrx which would be EJ255) shortblock. Anyway, besides rebuilding the motor and flashing the ECU to handle it, it's pretty direct. Remember though: It's not an EJ257 motor, it just uses the EJ257's 2.5L Shortblock.

wrxman420 12-15-2008 04:04 PM


isaacWRX2004 12-15-2008 07:37 PM

Well, problem is I blew my EJ20 on 04' WRX but I found an EJ25 off a forester that could possibly fit my enjine and I was wondering; would be a smart fix?

Kjott21 12-15-2008 07:44 PM

[QUOTE=isaacWRX2004;211284]Well, the problem is, I blew the enjine(EJ20) on my 04' wrx but I found an EJ25 off a foreseter. I was wondering would this be a smart fix? are the two blocks compatable? (EJ20 & EJ25)[/QUOTE]

Unless it was a Forester XT do not put that block in your car. The nonturbo blocks do not hold up to boost at all.

isaacWRX2004 12-15-2008 08:04 PM

The block I found was turbo... if swapped, will there be a major performance difference?

mosc 12-15-2008 08:05 PM

No, it would not be a smart fix. The Forrester engine uses a different ECU than you have. Your ECU is only good for EJ205 heads. No other heads can be used with it without serious cost. In other words, get another EJ205 or use the EJ205 heads you got on a different short block. Those are your only reasonable options <$5,000

You could conceivably use the shortblock from that Forrester engine but it would likely be a waste of money. You can get a new EJ257 shortblock for ~$1500 with zero miles on it. Much better choice IMHO. Even if I was handed an EJ55 from a Forrester in your situation for FREE, I'd probably still just sell it and buy a EJ257 shortblock (or another EJ205 if money was tight)

isaacWRX2004 12-15-2008 08:07 PM

Cool, thanks for the heads up.

All times are GMT -5. The time now is 03:59 PM.

Powered by vBulletin®. Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging v3.0.8pl1 (Lite) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

For the best viewing experience please update your browser to Google Chrome