2.0L to 2.5L engine swap in 2002 WRX

[sorsy]

Hello there guys. I am putting a brand new 2.5L STI motor in my 2002 impreza WRX. I am going to go with a Blouch Polka Pickle turbo, because it is a bolt on turbo and a little cheaper than going the perrin roatated way. What size of injectors would you run in this motor. The car is just going to be used for bombing around town, the odd race at the drag strip, and of course blowing the doors off the demestic car (i.e - mustangs and camaro`s lol) I will upgrade the fuel pump forsure, i already have a perrin front mount intercooler, AEM standalone egngine management system, full 3 inch turbo back exhaust, cold air intake. I had a 100 shot nitrous on the 2.0L motor but i will not be running that on this new motor, seeing how thats how i blew it up i think haha. I will just convert the nitrous system into a intercooler fogger. If you have any other upgrades that you would do please let me know. thanks for you help guys! SORSY

[wrxshotta]

is it an actual ej 257 swap or a hybrid with a 2.5 shortblock?...i would say 850cc's..also is your tranny built? seems like alot of power you had/ are going to have

[SuBeast]

Also; the actual STi motor swap is going to be a lot more complicated isn't it? I think you need the STi ecu, wiring harness and all sorts of other stuff to swap it, since the STi motor is drive by wire; and your 02 is not. Unless all of this gets overuled by the AEM...

[SilverSuby]

I agree with shotta, 850cc will do great for that setup but hes also right about the tranny. You are going to need to do something with it unless its an actual sti motor, then you can just do the easy thing and get an sti tranny. Plus, if it is an actual sti motor the ecu should take care of the rest but you will need all the harnesses.

[sorsy]

So what you guys are telling me is that i will need an sti wiring harness for this build? The stock harness in my car will not work? i have the AEM Standalone in there would that not take care of it? Thanks for the help guys!!

[mosc]

the worst thing isn't the ECU, it's the petals. The EJ257 is drive by wire.

[sorsy]

I do not think that it is a EJ257 i think it it i just the EJ25 but i am not too sure i pretty new at this, i am having a import custom shop help me along the way with it. is there two different motors ie (EJ25 & EJ257) your help is awesome thanks guys!!

[tuner ready]

The EJ25 is the 06+ WRX engine. The EJ257 is the 04+ STi engine. Make sure to check on the forums so the shop does not cheat you out of $$$. Is the shop a reputable shop or not?

[sorsy]

Yes the shop is a bunch of good guys. I did not get the motor from them tho i got it out of Saga Japan right from a wholesaler. Brand new still in the crate.

[mosc]

The two different motors are the EJ255 (Forester XT, Legacy GT, 06-08 WRX) and the EJ257 (04-08 STi). Unless your heads are busted up though I don't see why you'd swap in a complete EJ255. Most people just use the EJ257's shortblock with the heads from their EJ205 (02-05 WRX) and make a "hybrid"

[seanwrxwagon]

+1 for the hybrid

[sorsy]

So what your are telling me is that i should just pull the heads off the EJ20 and put them on the new EJ257 block...will i have as much power as a complete EJ257, or what is the advantage to that?? what is the differance between the EJ20 and the EJ257 heads? And what about the wiring if i was to do it that way? would i still keep all the same 2002 wiring harness and not have to worry about changing it over to the 2004 STi harness?

[WRXKidid775]

If it is a EJ257 then it has AVCS heads which IMO are worth the extra work of the wiring harness swap. you might need a new AEM im not sure though if you go that route.

[mosc]

The EJ205 heads are pretty good. You can make big numbers with them. Yes, the EJ257 heads are better but swapping those heads into a WRX is a pain. It's a lot more than the wiring harness. As I said, the petals even have to be swapped.

[seanwrxwagon]

1) Stick the WRX heads on the STi block. 2) Stick the STi heads on ebay or something and take the resulting profit and buy yourself something nice. New turbo, etc.

This will same you time and effort and still net you close to the same power. If you spend that profit wisely, more power.