2.2 to 2.5 NA swap?

[StatGSR]

hey guys, i drove grayguys GT today and i decided i kinda wanted a 2.5 in the wagacy. has anybody on here done this? i was trying to weed through some info on nabisco but u know how that goes. only thing i saw was that you could still run the motor on a 2.2 or 1.8 ecu. so i assume its strait up bolt in, plug in swap then?

[deadlydave]

i know there are differences in some of the sensors, so an adapter might be needed. you might need to find a 2.5 ecu somewhere too.

[SammyDaFish]

Depends on what year 2.2 and what year 2.5. If you swap in a phase 1 (DOHC) EJ25 in place of a 95-99 EJ22 it should bolt right up sensors and all. The injector size is different and the tunning is different, so you might not get as much power out of the EJ25 as it would on the correct ECU, but everything else is the same. Depending on years the temp sensor might be a little different but the pins are the same (switch and sending unit went to a single sensor with three pins) Any sensor/switch that's different you can just plug in the one from your 2.2

I'm doing something similar right now, Swapping phase 2 EJ25 SOHC heads onto a 2.2 along with the phase 2 manifold and turboing the whole thing. The only thing I had to custom make that didn't involve the turbo was a mount for the IAC. I'm using the top feed injectors and everything. It's pretty crazy how much stuff is interchangeable on Subaru's, they really are like legos.

[Wiscon_Mark]

If you're concerned about the tuning, you could spring for standalone ECU to better tune it - you'd get some performance out of that.

Might as well throw in cams & EJ22 heads (higher CR) for a bit extra oomph.

I mean, if you're going through all that effort for a bit extra performance, you might as well use that extra potential gained with the extra displacement.

[SammyDaFish]

if for some reason you did want to run EJ22 heads, you could just swap the short blocks and keep the intake the same therefore all your sensors and everything are the same. Despite the higher compression though, the ports on the EJ22 heads leave much to be desired. The DOHC EJ25 heads are better and the SOHC EJ25 heads are much better still. The downside to each of those head setups is that you need to swap the appropriate intake manifold and 2000+ scoobies use a stepper motor IAC valve which is incomputable with older solenoid types. other than that, everything basically plugs right in. Unless you have an EGR car, that's different too. The phase II EJ25 has higher compression than the Phase I too.


I recently swapped a 2003 EJ25 SOHC into a 98 outback. I had to make the adapter to mount the 98 IAC to the 03 manifold and an adapter for the EGR, but it worked just fine. That's where I got the idea for my turbo project.

[sheepdog]

Is statGSR really banned? How did I miss that??

[Wiscon_Mark]

Is statGSR really banned? How did I miss that??

No :lol: It just says banned.

[grayguy]

No he's not banned. I'm tellin ya, find me a ej22t and you have yourself a ej25 to use.

[StatGSR]

yea iv been banned for a couple weeks, no biggy... but yea, im not looking to go crazy with my legacy. its not like its my integra haha.

im just lookin for the 20extra hp and tq, and my current motor sounds like death, so i figured id look into it, even tho i do have a 93-2.2 hangin out in my garage...

[Plays_with_Toys]

I'm buying a high compression EJ25/22 combo in the next couple of months. He dynoed it at 143whp at altitude. The downside is you always have to run premium gas. However, compared to the maybe 92whp (on a good day) that an EJ22 makes, it's a huge improvement. If rewiring needs to be done it might be easier/quicker to just drop the block under your heads

[StatGSR]

^ i have no probs running premo, thats what the teg requires, its the extra mony on engine managment i dont like. but if your saying running it with a stock ecu on premo= teh win, then id be all for it.

[Plays_with_Toys]

It should work. The guy I am buying from has a 91 wagon, and is running his stock ECU on 91 octane and from time to time 89/91 mix. The only other mod he has is an exhaust. His car is OBDI, and so I don't know if it's going to do something funky when I go to my car on OBDII, but using my intake manifold should allow it to bolt in easier.

[Sarra]

Yeah, if you go from ODBI to ODBII, I&M gets a bit cheaper, assuming you go full ODBII route. At least in Oregon...

Yeah, why not get an EJ25D and do a bit of a build on it? You'll have it out and everything, prime oppertunity to build it up.

[StatGSR]

^ cause im not looking to dump money into my suby, and i know better than to play with a motor if im not willing to pay for proper engine managment, basicly all i really wana know is if a 2.5 falls into my lap for a good price, what if anything do i need to do besides bolt it up, and plug it in.

[jey]

^ cause im not looking to dump money into my suby, and i know better than to play with a motor if im not willing to pay for proper engine managment, basicly all i really wana know is if a 2.5 falls into my lap for a good price, what if anything do i need to do besides bolt it up, and plug it in.

Verify that everything does plug in - I had some problems with IAC incompatibilities with my swap. I got around it, but it still throws a bunch of CEL codes which is a problem with our emissions testing here in St. Louis. You can avoid the wiring problem by swapping the shortblock only.

You can get away with just an S-AFC, I think, with the swap you're proposing - no fancy engine management necessary. Bought mine used off of a friend for $150. Just tune the fuel delivery a little. I'm running a 2.5L turbo setup on my stock EJ22's ECU, and put Premium gas in the tank. Your NA setup should be fine.

[subaruhacman]

I have a 95 legacy that spun a bearing so I'm interested in putting a phase 1 2.5 in and have heard much about the vac problems with this switch. Any more info on that for me?

[Reason]

I have ECU's for a 96GT and a 97GT if you need a ECU.

[SammyDaFish]

I have a 95 legacy that spun a bearing so I'm interested in putting a phase 1 2.5 in and have heard much about the vac problems with this switch. Any more info on that for me?

that swap should go right in and run off your stock ECU. I'm not sure what the power difference would be having the wrong ECU in there and I dunno if you can just swap the ECU, but all the sensors on the engine are the same, save for that most DOHC EJ25s have EGR and EJ22's don't, well at least not in 95. So you'll have disconnected emissions equipment.