the comprehensive EJ205 swap thread

[legsportwag]

who has done it? i like many have tuned and tuned the living crap out of my 92 Legacy turbo, yet still feel like something is missing.. After recently driving a complete parts car (02 wrx) to my shop (and wracking my head for a year for tuning options) i have found the solution. REAL engine management!

so what does one do in this situation you ask? Well in all honesty i absolutely love my turbo just the way it is, for what it is. The plan is to not touch my 92 tw. its already 5mt swapped, td04, tmic, fcd, 25d heads on a 22e block.. in all honesty it rips and has been super reliable. I've had it for a year and has accumulated 20k more miles. Im just sick of workin on it in particular. and why tear down a good running turbo? right?

the plan is to find a 90-92 (non air bag) awd sedan. L, LX, LS whatever is found to swap, and since i have a complete EJ205/harness/ecu + 5mt swap just sorta laying around accumulating dust. I figure why not? I fully intend on keeping stock dash (from the legacy), door cards and interior and doing this the "wiring merge" way...

so as far as i have found, main differences between legacy and wrx body sensors n such are VSS (stock legacy cluster does put out vss to stock ecu, but the cluster is run by cable), and some fuel sensors that appear to be hidden within the WRX gas tank itself.. (line psi and fuel temp?) i belive...



this thread will have more added to it as i go along with this swap. im not keeping the 205 a 205, im actually building a de-stroked 25. will be the wrx crank in a sti block, pauter x beams and some drop in pistons (yet to be determined). Not to mention i still havent found a decent sedan worthy of 400hp.....

If anyone else has anything to add to this post concerning what is all involved in doing the complete ej205 wiring merge in our 90-94 legacy then please post it up!

[cj91legss]

I'm subscribing because I've been thinking about this alot lately. My thoughts were a 257 block with 205 heads. I havent researched anything on it tho.

[mike-tracy]

Friend of mine buys wrecked wrx's and sti's and swaps the dash, wiring and electronics over. As reliable as the car it came from, and no jerry-rigged splice jobs.

He hasn't done a 1st gen, but has done 2nd gen legacys and 1st gen imprezas. The dash has to be trimmed to fit, and I believe firewall modified, or hole(s) cut into it. Slavic.86 on rs25 and elsewhere.

[legsportwag]

The point of this thread is to figure out the proper way to swap the 205 harness. Im particular to keeping the original dash with the car. I don't want a wrx dash that doesn't fit.. If I wanted a wrx interior I'd build a bug eye. But I don't..

Brydon on rs25 has an amazing write up on merging the wrx harness with a rs. But as far as my research Has found no one has done this merge with a 1st gen legacy.

[mike-tracy]

There's at least one (former member?) on here with an ej205 swap. Maybe it's Livestrong14? Jake_15 has a full ej257 swap in his 90. I'm not sure exactly what Jake_15 did to his, but he's running the original dash (albiet with a JDM GC8 cluster).

People you're talking about who have merged the wiring, have done so on OBD-II cars. I don't want to dissuade you from your path at all. But... For the money to swap in what you need and merge wires with a 20+ year old car's, I would think reliability would take a hit. If that's not an issue to you, then what about a standalone? I've talked to several local tuners regarding open-source tuning on the newer engines, and each told me that it was limited, relatively speaking, to a decent standalone computer. Resolution of fueling tables, fine tunability, etc. Stuff I don't know much about.

[legsportwag]

Livestrong14 runs piggy back... Jake15 seems to be close, but used a rs cluster. Who knows how much of the original legacy harness he used... Hope he posts up on what he did.

[robertpaige]

I think Jake did a full STi swap including harness.

Subbing because I'd love to do a EJ205 swap in my wagon someday, I think it's definitely worth doing the research on and submitting for future reference.

[legsportwag]

Oh its just a matter of time till I take this merge on. Already have the wrx side of the harness, just need a legacy to merge with.

[robertpaige]

Have you thought about contacting places like iWire to do the merge?

[legsportwag]

Trying to hunt down the harness from my tw 5mt donor (90ls wag 5mt) that I gave to a friend who wanted to Subaru power an ae86 coupe.. A year ago lol. Could be promising for a harness to merge the wrx ecu with.

[legsportwag]

Taking my time on this, although I've done tons of research. From what I have gathered people are saying a lot of codes can be deleted from the wrx ecu. So now the question of what do and don't I need to run the wrx ecu.

I've got a line on a couple legacy's right now. Just waiting on something to come thru.

[robertpaige]

Yeah the ECU is great in the sense you can turn off codes and things like that, OBDII has a lot better compatibility with most things.. scantools, tuning, etc. I mean 300awhp is pretty easily achievable with the same RobTune setup on our cars that maxes out around 260awhp.. 550's, VF39, 3" TBE, supporting mods, etc. It would be awesome to have a WRX setup in a Legacy shell... thing would be quick.

[legsportwag]

Still working on this swap, still have not gotten a shell to swap though. Working on a 5mt swap in as 90 ls wagon to be the new bass cannon. (Dual alternators, Rockford fosgate t4000.1bd, 4 dc audio m3 8"s)..

[legsportwag]

How about an update

[cj91legss]

Nice!!!, pending an approval on a thousand dollar loan I may be doing an 02 wrx swap in my 92. Ill be researching the build info here and other threads.

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[cj91legss]

How's your progress going? I started my swap...

[ASTRO]

I didn't do the same thing that you guys are talking about with swapping the engine...but I did swap a 2002 EJ205 ECU into my 93 SS, and actually got it running for the first time today.

Here's a list of the sensors/electronics that I used for the swap/conversion:
-stock 93 EJ22T crank sensor
-2002 WRX crank timing sprocket
-2002 WRX camshaft position sensor (tried to get my 93 sensor to work but the ECU wasn't liking it)
-stock 93 EJ22T Throttle Position Sensor (swapped power/ground pins to get proper reading for WRX ECU)
-stock 93 EJ22T injectors
-stock 93 EJ22T MAP sensor
-2002 WRX MAF Sensor
-2002 Impreza RS A/F Sensor
-2000 Phase 2 EJ22 Driver's Side Can Sprocket

All of my wiring "merge" was done under the dash by de-pinning the OEM 93 ECU plugs and then matching them up with the appropriate wires from my WRX ECU pigitails. All wiring is reversable too, did not cut any pins off the OEM main harness. The factory 93 gauge cluster is fully functional, and if you didn't look under the dash you would never know the ECU was swapped.

Since the WRX uses a coil-on-plug ignition setup I joined Ignition Control wires #1 & #2 together (using Diodes to prevent ECU backfeed), and #3 & #4 together. Stock waste spark coil fires just fine and I have not encountered any issues yet.

I currently have no Idle Air Control valve, as I have not come up with a way to attempt to get the WRX ECU to control it. For now I have the idle screw set so it idles at approx 1200rpms.

Even wired up an OBD-II port for scantool usage and reflash tuning. I currently use RomRaider for tuning, and have confirmed reading and flashing work just as it would on an 02 WRX.

I only have pic after I first got the ECU powered up, showing that it communicates with the SSMII. I do have all of my wiring charts and I/O charts available, so they could be used as a reference.

Communication success, the car thinks it's a 2.0L Turbo now


and heres a quick, crappy video of it running for the first time on the 02 WRX ECU, and Romraider is hooked up and logging, confirmation that it all works.

https://www.facebook.com/photo.php?v=10 ... 5470011893

[cj91legss]

Wow, nice!!!!

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[86BRATMAN]

What cam gear did you use, I see no mention of changing it. But I know wrx uses a 2 trigger gear as opposed to the phase 1 7 trigger.

[James614]

Wow that's amazing. +1 on the cam gear, I've read that's been the #1 issue stopping these types of conversions.

[86BRATMAN]

One could use the ej222 cam gear, it's a single cam, and has the correct trigger pattern. I'm just curious if that's what was done there and he forgot to mention it.

[ASTRO]

Oops sorry guys I didn't realize I left that off the list... I used a 2000 Phase 2 EJ22 driver side cam gear.

--Sent via XT1080--

[cj91legss]

What heads did you use?

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[Legacy777]

Have you scaled or reconfigured the WRX ECU to use the 93 injectors & MAP?

[James614]

Please tell me a variation of the EJ205/257/207 cam gear works on the phase 1 DOHC heads....