EJ205 swap into my 97 LGT, need some help

[98legacygt22]

Ok so I am swapping in a Wrx EJ205, I contaced Iwire to merge the wrx harness to my legacy harness. How much wiring from a wrx do I need? I am starting to get a little confused. This is the message I got from them (they seem to be an excellent company to do business with!). Also aside from everything under the wrx hood, what else do I need? I am retaining my original legacy transmission.

Hey Brett,
Thanks for contacting me. I can definitely do that. I'll need the underdash harness from the Legacy GT and the complete harness (except what's on the engine) from the WRX including the ECU and fuel pump controller.

Looking forward to doing business with you,
Brian

[chuckthefuk]

This is the engine harness (the section they do not want you to send)
http://img4.imageshack.us/img4/7963/harness.gif

This is the (main) engine bulk harness
http://img14.imageshack.us/img14/8844/harnesshood.jpg

This is the body bulk harness (under dash)
http://img151.imageshack.us/img151/7445/harness2.jpg


Both the body bulk harness & engine bulk harness should be 1 unit from the factory. They are wired together.


The WRX ECU uses 5 main connectors A-B-C-D-E
--> within these 5 connectors are various engine wiring and body wiring.
https://sl-i.net/FORUM/images/imported/2012/12/OEMECU2-1.jpg

You can see here how all wiring is bundled together
https://sl-i.net/FORUM/images/imported/2012/12/wrx_ecu-1.jpg

..

Where did you get your donor wrx harness from?

-Chuck

[98legacygt22]

Chuck, you are the man! I haven't picked one up yet but would you recommend a certain year/model wrx to get it from? I want to stay in the 02-05 range

[MonstarMotorsports]

i guess i've never understood why you would go threw the extra work time and money to merge the two harnesses together. If your using a wrx ecu and wrx motor. why not use strictly wrx wiring? its all plug and play... no reason to merge anything. You can put the wrx harness in the legacy chassis. it takes a little work, but its far easier and cheaper than merging two of them together. and what little merging you have to do from the wrx harness to fit the accessories in the legacy is pretty simple.

[chuckthefuk]

...
Not everyone wants to run the WRX cluster and hack up their dash or do a dash swap.

Not everyone wants to spend hours and hours re-soldering each accessory connector back on. Not everyone wants to trace and solder their HVAC / blower controls.

As easy as it may be for you.. not everyone is up to that large of swap.

"98legacygt22" -> I cant help you narrow down a EJ205 wrx motor to use.. Good luck with your research
-Chuck

[98legacygt22]

...
Not everyone wants to run the WRX cluster and hack up their dash or do a dash swap.

Not everyone wants to spend hours and hours re-soldering each accessory connector back on. Not everyone wants to trace and solder their HVAC / blower controls.

As easy as it may be for you.. not everyone is up to that large of swap.

"98legacygt22" -> I cant help you narrow down a EJ205 wrx motor to use.. Good luck with your research
-Chuck

I'm actually getting a motor from my buddy that has a spun rod bearing, I already bought the heads and intake. I plan on tossing a brand new crank and rods in from Subaru and maybe ACL race bearings.

[chuckthefuk]

Ahh I remember now.. I am L.S.D on facebook..

:-D

[98legacygt22]

Ahh I remember now.. I am L.S.D on facebook..

:-D

HAHAHA I kinda thought your display pic looked familiar

[MonstarMotorsports]

...
Not everyone wants to run the WRX cluster and hack up their dash or do a dash swap.

Not everyone wants to spend hours and hours re-soldering each accessory connector back on. Not everyone wants to trace and solder their HVAC / blower controls.

As easy as it may be for you.. not everyone is up to that large of swap.

"98legacygt22" -> I cant help you narrow down a EJ205 wrx motor to use.. Good luck with your research
-Chuck

you dont have to run a wrx cluster. repinning for the legacy cluster if you'd like to keep it is very simple anyone should be able to do that. and hours and hours merging two harnesses is far worse than any accessory. Shit most the time the window and door lock plugs are all the same even. your hvac is tipically the only problem and again, its a lot simpler to make that work, than make a motor run with no CELs.

[elislider]

...
Not everyone wants to run the WRX cluster and hack up their dash or do a dash swap.

Not everyone wants to spend hours and hours re-soldering each accessory connector back on. Not everyone wants to trace and solder their HVAC / blower controls.

As easy as it may be for you.. not everyone is up to that large of swap.

"98legacygt22" -> I cant help you narrow down a EJ205 wrx motor to use.. Good luck with your research
-Chuck

you dont have to run a wrx cluster. repinning for the legacy cluster if you'd like to keep it is very simple anyone should be able to do that. and hours and hours merging two harnesses is far worse than any accessory. Shit most the time the window and door lock plugs are all the same even. your hvac is tipically the only problem and again, its a lot simpler to make that work, than make a motor run with no CELs.
by this logic, why bother even doing anything right? just add the entire wrx harness into the car and use jumper wires to connect them together. oh wait that would be idiotic.

the only correct way to do an engine swap without a complete dash swap and interior conversion is to lay out both complete harnesses side by side (on paper in a spreadsheet and then physically) and match up what stays with the car (original harness) and what the engine and ecu need (swap harness), merge the together effectively replacing a section of stock harness with the swap harness. the theory is the engine and ecu won't realize they arent still in the donor car, and the chassis won't realize it doesnt have the original ecu/engine in it. then all your doors, lights, windows, dash, hvac, cluster, etc all still work as originally intended.

thats what iWire does for you, but you have to send them both complete bulkhead/dash harnesses so they can merge them.

as chuck said, why would you want to "merge" your harness and every single connector and pin when you can just go to the joints of the harness, spread all the wires out, and merge only what you need to for the specific application.

[98legacygt22]

Ok so after reading a DIY on how to merge the harness I am going to just do it myself, I never thought it was that easy. What wrx would you guys recommend getting an ecu/wiring from? To me it doesn't matter as long as I can plug in a tuner to it eventually (when I up the boost once the engine is done breaking in)

[grayguy]

Just go with what ever year motor you have would be my suggestion

[elislider]

02-05 WRX wiring, any are fine. try to find one that is from a manual, assuming your car is a manual.

[98legacygt22]

Ok cool, I will figure out what year the engine is from then go from there. I cant wait for this to be done, should be so much fun

[98legacygt22]

So do I need to pull the harness that goes to the fuse box under the hood? A tid bit confused at the moment.

[chuckthefuk]

Nope thats the body harness.. you want all the wires that come off the motor that run into the firewall (next to the turbo) and all the wires that lead back to the 5 ECU connectors as well as a portion of the wires that flow into the dashboard.

[98legacygt22]

Nope thats the body harness.. you want all the wires that come off the motor that run into the firewall (next to the turbo) and all the wires that lead back to the 5 ECU connectors as well as a portion of the wires that flow into the dashboard.


Ah I hate myself now... I pulled the fenders and started to pull the wiring out.. dammit. I got the dash most of the way out, getting the wiring out of it is the tricky part.

[98legacygt22]

Ok started to get some of the dash harness out. Having trouble figuring out how the Hvac stuff comes out.

[elislider]

think of it this way. all of the wires between the ECU and the engine are what specifically run the engine. if you replace those wires with the engine<-> wires from another car/engine, then the only thing you have to worry about are the wires that leave that section of the car's wiring and run other things. there isnt much that communicates from the ECU to other parts of the car that isnt the engine except things like fuel pump and gauge cluster (for speed, tach, oil pressure). most of the other wires are obvious stuff like power and grounds.

[98legacygt22]

think of it this way. all of the wires between the ECU and the engine are what specifically run the engine. if you replace those wires with the engine<-> wires from another car/engine, then the only thing you have to worry about are the wires that leave that section of the car's wiring and run other things. there isnt much that communicates from the ECU to other parts of the car that isnt the engine except things like fuel pump and gauge cluster (for speed, tach, oil pressure). most of the other wires are obvious stuff like power and grounds.

Thanks man, so what EXACT wiring do I need to get from a Wrx? I want to get this project going asap. Tired of driving the outback with a slipping clutch lol

[chuckthefuk]

http://img832.imageshack.us/img832/6717/35997928.jpg

[98legacygt22]

Chuck I must again state that you are the man!

[chuckthefuk]

Its very hard for me to show you how much of the dash harness you need. You only want 1 foot section coming from the firewall towards the dash. These items are the the ones that you have to merge.

The rest of the harness will just plug into the wrx ecu (5 x connectors)

-Chuck

[98legacygt22]

Ok cool, yeah it seems pretty simple. Just remembering where all the bolts go is a pain. Luckily my daily is a 98 Outback and is the exact same :grin:

[chuckthefuk]

Heads up ... grab the f***ing boost controller (solenoid) sitting on the passenger strut tower where the 2 vacuum lines are going into it.

http://img7.imageshack.us/img7/5690/img7800m.jpg

And post some damn pictures of your donor and harness pull.. Share the love for SLi.

[98legacygt22]

I dont have a donor car, im just buying the harness and related parts but I will take pics of the legacy part of it

Sent from my SCH-M828C using Tapatalk 2

[lord flashheart]

im glad u decided to dig in and give it a shot! its alot of head aches, but when you go for the first drive its so worth it.
as for the wiring thing,
personally im a standalone kinda guy.. it leaves the freedom to set everything up the way you want it to be.

but if i had to pic between swapping a complete or merging. (which ive helped with swaps doing it both ways...
i would say the easiest/fastest/best way in my honest opinion, would be get the WRX wiring harness, take it to a professional, and have him strip all the non essential BS out of the harness that is not pertanent to running the engine, then have him put a plug for your essential stuff that you would need to tap into (fuel pump, fans etc). then on the car side, tap into those specific items and run them to the other side of the plug.
leave the legacy harness in the car, and remove the ecu. basically have your wiring guy make it into a standalone harness, only using the subaru computer.

thats the easiest way i have seen it done. and they run pretty good. it saves alot of head aches.
http://enginewiring.com/ i have seen some of his work, he is really reasonable on price and does good work.

[lord flashheart]

i do want to say this tho, that guy at enginewiring.com, is a little weak on experience with subarus so it will take some time and patients.

[98legacygt22]

I'll wind up doing a harness merge on whatever RUST FREE chassis I end up with (might even get a forester!). Started to get into the wiring and looking at the rust around the windows, rockers, quarters, etc just makes me realize swapping this legacy is not worth it.

[grayguy]

My buddy does harnesses too, he wired my stanealone in no problem.

http://www.numbchuxconversions.com/home.htm

[lord flashheart]

Sometimes it is best to pay someone rather than gehtto rig shit together to save a buck.

[grayguy]

^agreed 100% ! I was happy to pay someone who knew what they were doing to wire my car

[98legacygt22]

Sometimes it is best to pay someone rather than gehtto rig shit together to save a buck.

Also agreed, however I am not one to ghetto rig stuff hence the reason this car has taken so long. It's being parted out and I'm keeping my turbo stuff for whatever it is I buy, would like a forester as they seem like they would do better off pavement.