EJ20X swap?!

[Zac88]

I'm going to attempt this swap soon. One night I'm going to make a thread with links to all the information on the forums for future reference

[Gabo]

I think in another thread someone got the USDM ECU working with the dual AVCS just by adding a few wires.

 

I did extensive research back a couple of years ago regarding this swap, but don't remember much other than I know there is a harness you can purchase that will add the necesarry wiring to operate the AVCS without needing to splice the OEM US harness. The car will also run on the US ECU but the AVCS system will be disabled. I remember mention of this being the only option to pass the OBD2 check.

[iSooby]

Unless I'm mistaken, he could use the engine, just swap over intake, sensors, Turbo, Intercooler, AVCS and get a custom tune... Someone please chime in, as this is from reading all of the engine threads. Or, he could use the twinscroll setup if he has the JDM TMIC...

 

Thanks,

 

Steve

 

this is correct i have a friend who just did this in his obxt and aother who did the same in a baja xt

[Subieguy203]

Okay so all I gotta do is add the wiring and disable the avcs with a tube ?

[Zac88]

After reading a nasioc thread. You need to park the exhaust cam at a certain place or you'll have very late turbo spool.

[l88m22vette]

I think in another thread someone got the USDM ECU working with the dual AVCS just by adding a few wires.

 

My EJ20Y swap, I did my best to cover every aspect, problem, and solution I encountered: http://www.subaruoutback.org/forums/109-gen-3-2005-2009/416186-2005-xt-jdm-spec-b-swap-imported-front-clip-auto-manual-conversion-bolt-ons.html

 

The USDM ECU CANNOT run exhaust AVCS, you have to add wiring for the exhaust cam sensors and oil control valves, install the JDM ECU, and reprogram the immobilizer to make it all work.

 

edit: make sure to use the Photobucket extension for Firefox, Chrome, or whatever browser you're using

Edited May 11, 2018 by l88m22vette

[Subieguy203]

Okay, got it thanks for the much needed help guys !

[blxcksheep]

I Have ej20x/y installed with USDM headers, up pipe, turbo, downpipe, tmic etc. I want to run the full twin scroll and I'm pretty sure I have everything jdm that's needed, but I want to know if the downpipe will be same length and if the o2 sensor will cause any problems being on the opposite side of the pipe than the USDM?

 

I don't know how my mechanic did the swap but judging by the previous post, I'm assuming that my AVCS isn't set up since the A/C does run and I'm using stock ecu, yet I'm told its all working. How can I confirm this?

[l88m22vette]

I got an HKS downpipe used off of buyee.jp, it was perfect and bolted right to the stock exhaust. You'll have to looks for wiring coming off the front bottom corners of the engine on both sides, there is a cam sensor and oil control valve on each side (next to the exhasut cams)

[maxspeed3]

Has anyone used an 08+ sti engine wiring harness instead of running the wires for the exhaust avcs to the bulkhead? I'm going to be doing this swap in my 05 lgt very soon too.

 

I've looked at the pinouts of the bulkhead connectors between the two cars and they appear to be the same just the addition of the avcs wires I'm wondering if all of the connectors for the various sensors are the same on the usdm and jdm motors. I wouldn't think subaru would change the connectors around between usdm and jdm.

 

 

Sent from my SM-G955U using Tapatalk

[Shello007]

Would anyone be interested in purchasing a EJ20X that's currently installed in a legacy? Saves you having to do the intake and exhaust manifold and all that.

[Zac88]

How hard would it be to use different exhaust cam and cam gear? Like maybe stock v7 ej207 cams and cam gears. Edited May 15, 2018 by Lonely Driver

[l88m22vette]

Lots of little stuff could be different, I had to swap injector plugs since I installed topfeeds instead of the stock sidefeeds, and when you're talking about using Impreza parts on a Legacy it can get more complicated. I had looked into using a USDM ECU for the dual-AVCS but never went down that road, it *seems* like it could work as long as the wiring and immobilizer are handled, but that's beyond anything I did.

 

 

 

You can swap to static exhaust cam gears but you have to degree the cams, they have fully-retarded timing when the AVCS gears aren't active. The cams are all basically the same, its the variable timing itself that makes the difference.

[DuveyB]

gonna be doing a ej20y swap in the coming weeks, question on the wire harness, the do you have to use the USDM engine harness or can you use the JDM harness? the motor i got is very low mileage, looks pretty much brand new and the harness is immaculate, the USDM one is already pretty beat

[Aquiniano]

Does anyone know where I could get a 20X turbo Inlet?

[subie2nr]

Thanks mondtster! So basically you got a spool of something similar to this? Was there a reason you didn't go with the JDM engine harness?

https://www.wireandcableyourway.com/belden-9460-18-awg-1-pair-multi-conductor-single-pair-cable-tinned-copper-pe-insulation-pvc-jacket.html?gclid=CjwKEAiA2abEBRCdx7PqqunM1CYSJABf3qvau8TVVRhwa-GWPhNFfYnqmB6K_nMZe0GiMCoapnpnTxoCi1nw_wcB

 

Whenever I go for the engine, I plan on grabbing year appropriate ECU with connector plugs and a couple inches of harness to de and re pin. In reality I was hoping to get the complete engine with harness, and run an overlap harness like you mentioned from the main engine connector back through the firewall to the new ECU. Again, really need to dig into the pin out for the JDM and USDM to see if that's feasible without a lot of re pinning.

 

 

 

 

Ah, thank you for giving some actual real world feedback. I feel like a thread like this could use it until more of us go through with it!

 

When I mentioned 20G I meant I thought kingugawa had offered a proper flanged TD05-20G unit. Fully aligned with you on the TD04-20T. Thanks for the links too, I may be needing them!

 

We do this in the Saab world all the time. My '08 saab 9-3 aero has a td-04, and it has been sent out to get a 20G, even a 22G (i've had many). I picked up a 2010 LGT, did the ej20y swap, usdm heads (2.5), usdm ecu, usdm cams (exhaust side shouldn't be a problem since the LGT came with it stock), and waiting for an oil pan leak to be fixed before playing around with the tune. I'm interested in seeing what I can do with the jdm 2.0l until i fully build a 2.5. At the end of the day, the aero is faster. That same turbo set up on the 2.8l does 420hp, 510 ftlb. But I like the all wheel drive, and those 2.0l are so cheap to replace i feel like i'm buying honda engines again. So i don't mind blowing up a few for the sake of research. Hopefully XRT will get exercise it's demons and give me a peppy, everyday car that can handle my trips North.

Edited February 11, 2020 by subie2nr

[NinoS]

I've checked out this thread previously for info - this is one of the better sources of info for this swap so figured i'd join and relay what I have going on...

 

I have an 05 Forester XT Auto with this ej20x swap (the timing belt has the guide so I assume I have the x version), that i've since rebuilt the EJ20x engine on - when I got the car the EJ20x was already installed and running on the stock ECU that had been "tuned" via AP at some point (or maybe flashed back to stock, but still AP locked), albeit for only around 120 max hp per the initial dyno run.

 

I'm using the stock USDM ECU and harness with a (new) pro tune via Cobb AP, exhaust AVCS not hooked up. The exhaust AVCS sensors I have removed and capped due to oil leaks. I'm running a VF48 turbo, cobb downpipe, 3 port EBCS and currently making 240whp, conservatively tuned. The engine is slightly lower compression than stock due to the pistons we used in the rebuild, which was not a "go for big power power" rebuild, rather lets get this thing running reliably for years to come at reasonable power levels, while not spending more than the price of another used EJ20x @ 1K or so. My friend/mechanic built rotating assembly, I did everything else, learning a ton along the way (often the hard way). The car runs great, although the low end can be a bit wanting at times but i doubt that's big news to anyone. Current limiting factor for power is fuel per the tuner - i have a DW200 fuel pump but still on stock side feed injectors and i'm in no hurry to do the top feed injector conversion - i'm listening to my tuner on avoiding bigger side feeds.

 

At the moment just enjoying a 95% sorted car and tackling some other drivetrain stuff recently like bearings now that it's running nicely and reasonably quick once boost kicks in. One day I might chase more power starting with the top feed conversion.

 

As you can probably tell I'm far from an expert but i have tons of part numbers I used on the rebuild if anyone needs one.

[alexk1031]

I've checked out this thread previously for info - this is one of the better sources of info for this swap so figured i'd join and relay what I have going on...

 

I have an 05 Forester XT Auto with this ej20x swap (the timing belt has the guide so I assume I have the x version), that i've since rebuilt the EJ20x engine on - when I got the car the EJ20x was already installed and running on the stock ECU that had been "tuned" via AP at some point (or maybe flashed back to stock, but still AP locked), albeit for only around 120 max hp per the initial dyno run.

 

I'm using the stock USDM ECU and harness with a (new) pro tune via Cobb AP, exhaust AVCS not hooked up. The exhaust AVCS sensors I have removed and capped due to oil leaks. I'm running a VF48 turbo, cobb downpipe, 3 port EBCS and currently making 240whp, conservatively tuned. The engine is slightly lower compression than stock due to the pistons we used in the rebuild, which was not a "go for big power power" rebuild, rather lets get this thing running reliably for years to come at reasonable power levels, while not spending more than the price of another used EJ20x @ 1K or so. My friend/mechanic built rotating assembly, I did everything else, learning a ton along the way (often the hard way). The car runs great, although the low end can be a bit wanting at times but i doubt that's big news to anyone. Current limiting factor for power is fuel per the tuner - i have a DW200 fuel pump but still on stock side feed injectors and i'm in no hurry to do the top feed injector conversion - i'm listening to my tuner on avoiding bigger side feeds.

 

At the moment just enjoying a 95% sorted car and tackling some other drivetrain stuff recently like bearings now that it's running nicely and reasonably quick once boost kicks in. One day I might chase more power starting with the top feed conversion.

 

As you can probably tell I'm far from an expert but i have tons of part numbers I used on the rebuild if anyone needs one.

 

I am about to start this swap too as I have spun a bearing in my 255. Could definitely use someone that has done this recently to answer my questions or give kind advice.

[alcyonegtb]

Has anyone ever seen the factory JDM map? I'm very curious on how the AVCS and Ignition timing are setup.

Under standard timing belt setup, i was able to get waaaay more pull out power with starting the timing at 20 degrees at 0 load and ending at 10 degrees at load of 2.5. I also added 25 degrees of AVCS across the board on 800 & 1200 rpms. Its a dramatic difference! and I'm wonder what kinda truth is in retarding the exhaust cams to increase overlap, effectively adding AVCS across the board to maybe match the stock setup on a standard engine with on single AVCS?

[Protegejustin19]

I have a base map for ej20x with a vf52 and stock fueling if anyone is interested

[alcyonegtb]

I have a base map for ej20x with a vf52 and stock fueling if anyone is interested

 

Like the JDM factory map? or a custom base map?