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EJ205 swap to JDM EJ205

54K views 24 replies 5 participants last post by  titter 
#1 ·
Hi everyone new on here. Now I've read a lot of different post on motor swaps and have done a lot of research. So hear it goes... First off this is not my car this is my wife's sisters Bf car. Now I have built V8's and motorcycle motors and can do just about any type of mechanical job's.
The car is an 2004 WRX 2.0 turbo Automatic with a bad motor spun a main or rod bearing. I've found a JDM replacement motor on ebay it's from a 2004 WRX I know that you need to use intake and exhaust manifolds off usdm and all the other parts like PS, AC, ALT. Also saw that you have to change the drivers side intake cam gear and crank timing gear or it wont start. Is there anything else I'm missing?
Also while I'll have the engine out was going to change the timing belt and wheels along with water pump, possibly head gaskets. Anything else I should do at this point? Thanks for any info..
 
#2 ·
the JDM motors i believe has ACVS, which can be a pita to wire up. but i believe u can just leave it disconnected. other than that, i think you got it all covered.

also heres this: its for an 03 but it should have all the info covered
http://forums.nasioc.com/forums/showthread.php?t=2579471

good luck :) and welcome to the forums
 
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#4 ·
honestly im not 100% sure when ACVS was introduced into USDM engines. i just know it was available on almost all of the JDM EJ205's. but there are some non-acvs JDM engines. alot of people just leave it disconnected because apparently its a huge hassle unless you just throw money at a tuner and say "fix it!!"
 
#6 · (Edited)
IA Performance has a bulkhead wiring harness to use the AVCS.

Here's the link: IA Performance Subaru AVCS Bulkhead Wiring Kit

I'd first confirm if it has AVCS and then install this kit if it does. It is optional, but my tuner says AVCS is worth 30-40 Hp.

Oh yes, I have AVCS working in my '04 WRX now.
 

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#8 ·
AVCS was introduced to the USDM wrx on the MY06 wrx, also there are EDM wrx with AVCS but not all. LW_Black4 care to shed some light on your AVCS in a new post so those of us considering swapping heads can get a better idea if we really want to do it?
 
#9 ·
@RoboTuner

I bought a JDM v7 EJ207 and had it installed in my '04 WRX. v7's are drive by cable and have AVCS.

You'll need the JDM ECU and the IA Performance bulkhead wiring harness to get the AVCS to work, as the '04 WRX USDM ECU doesn't support the additional signals for the AVCS. @psinuse made his own bulkhead wiring harness, but he's incredible.

A tuner put a '94 octane tune on the JDM ECU and an emissions tune on the USDM ECU for one package price. I swap to the USDM ECU every 2 years for an emissions test and run the JDM ECU normally.

It just seems wrong to me - especially if you are seeking power - not to use the AVCS, but I do realize that it's optional.
 
#10 ·
LW_Black4 When you had the EJ207 installed did you have them replace any motor components? Like Timing belt, water pump, Head gaskets? When I do my swap was going to do those just to be safe. What are your thoughts on changing the oil pump as well?
 
#11 · (Edited)
I'd change the timing belt kit, which has the water pump. It's easier to do with the engine is out and you'll know when the timing belt was last changed for future service work.

Oil pump is not as important, as it has a much gentl-er service environment - immersed in oil. I would check the oil pump pickup for cracks though if you are removing the oil pan - even though I didn't. Ha ha.

Instead of replacing the oil pump though, I'd upgrade to an STi pan: "06-07 Subaru STi Oil Pan and Pick-up". I wanted this but didn't have the opportunity. Below is the link:

06-07 Subaru STi Oil Pan and Pick-up
Flatirons Tuning - 06-07 Subaru STi Oil Pan and Pick-up

I wouldn't remove the heads unless there were head gasket issues. Once the heads are removed the block or heads may need to be resurfaced and then you're into a complete rebuild.
 

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#12 ·
i agree, if you have it, i dont see why you wouldnt use it. but again it needs to be tuned for it. you cant just engange the system and hope for the best. so it falls under the "tuner fix it!!" category. your average shadetree mech just leaves it alone as you need to spend extra money on a proper tune as well as the installation and harness.

@LW_Black4 how hard is swapping the ECU's for emissions? im assuming u have both USDM and JDM on hand... is it just plug and play? never heard of this and it sounds brilliant!
 
#14 ·
Yeah I have done a few timing belts on these engines not a big deal, Okay just thought seeing the motor was out to do the head gaskets but I see your point about having to resurface the blocks and heads. The pick up tube and pan seem to be a good idea again seeing it's out of the car. Thanks again for the info @LW_Black4
 
#16 ·
The wiring harness was very straight forward to make, you are only really adding 5 wires to the ECU side and 4 to the actual plug that goes to the motor. The biggest pain is repinning the ECU, but with the right tools, or in my case improvised tools, you can build one yourself. I suppose I could do a write up on it, but it might take a few days.
Unless you are going to be doing serious racing, stick with the STI pan, baffle and pick up. Not knocking Killer B's stuff, but out of all the cars I have worked on and built over the past years, I have never seen one with a bad pick up. Clogged because they didn't care for the motor, yes, but never broke.
The banjo bolt on the cylinder head to the AVCS and turbo, pull the screen out of it.
If you do the ECU swap, for the love off all that is holy, DO NOT PLUG THE ECU IN WITH THE BATTERY HOOKED UP!!! Make sure your connections are correct or you can fry the ecu.
 
#17 ·
The biggest pain is repinning the ECU, but with the right tools, or in my case improvised tools, you can build one yourself. I suppose I could do a write up on it, but it might take a few days.
Keith,

Are you able to add AVCS signals to your USDM ECU then, once the bulkhead wiring harness is in place?

Are there spare channels in the standard '03 WRX map then that can be used for this?
 
#19 ·
Motor swap complete after a few bloody knuckles and f* bombs got it all in. Worst part was getting the Torque converter to go back into the transmission that and you need very small hands to get to a lot of places! Added a few things that my friend wanted on like a new blowout valve and colored hose kit. I did go with the STI oil pan and pick up as well as the racing timing belt with all new pulleys, water pump. had to change the inlet tube to the turbo stock one was torn right at the turbo! That couldn't have been helping how it was running!! But the end result is turned the key it fired right up no high idle and no CEL!!! YAY!!!
But like I said had a herd time getting the Converter in well ended up damaging the seal so it's leaking Tran's fluid pretty good!... UGH!! Now have to pull the trans to fix that!!! So Mad at myself for this!! Will post some Pic's of the motor and video after I fix the Trans leak!!! :/
 
#21 ·
I second what @titter said, unless you're running over 20psi or it's failing you have no need to use a BOV, and when you use a BOV instead of a BPV you run rich between shifts (more so on manuals) so you may foul your spark plugs faster.

As for the A/T fluid, did you tear the seal for the trans input shaft or is it leaking at the seam around the edge. One is fixable the other requires replacement of the unit!
 
#24 ·
I don't have the stock one, It's aftermarket recirculate/ BOV valve all billet aluminum I have the end capped off so it don't blow out the air. The stock one was removed by a garage and had some cheap BOV on it and they didn't have it hooked up right.
Not sure on the leak think the seal is damaged and needs to be replaced. So I pulled the Trans out!! What a nightmare that was to do, thank god I had a lift to do it on! It was the Seal around the input shaft that was damaged. Also I don't think I had the other shafts lined up correctly either. The seal was easy to replace lined up the shafts to the Converter and it slid right in with a half turn. For anyone Pulling the trans out jack up the front of the motor cause there is no room to pull it back out or put back in. Also this would have been a HELL of a lot easier with a Trans jack!! Ended up with Two other guys we picked it up and put it in! In the end fixed the leak and car run's strong with no leaks this time!!
 
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