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View Full Version : Some questions about a 04 WRX Wagon EJ20T in a 99 Legacy Wagon



twistedsymphony
08-19-2021, 02:42 PM
I know this sub-forum has been dead for a while but I'm hoping maybe someone sees this and can clear up some swap questions I have.

I've got a 99 Legacy GT Wagon, and I'm picking up an 04 WRX Wagon and I hope to put the WRX motor in my 2ng Gen.

This is not my first engine swap, but it is my first Subaru engine swap.

I've been reading through swap threads and build threads for a week now and I think I've got most of it understood but there are still 2 areas I could use some clarity.

1. I know I need a "turbo" cross-member but will the one from the WRX work or will I have to source a different one? if so is the 1st Gen Turbo Cross member the only option or are there other suitable cross-member options I can hunt for?

Similarly can I use either the Legacy or WRX steering rack? if not what rack do I need to hunt for and will I need a steering column adapter?


2. I'm assuming I can use the WRX downpipe and the Legacy Axle Back, but what are people doing for a mid-pipe/cats? are there aftermarket or OEM options that work or will this need to be built custom?

Any help, or links, pointers, or names of people who might have answers would be greatly appreciated, Thanks!

mike-tracy
08-19-2021, 02:53 PM
1. The WRX wagon crossmember will bolt in. The WRX or LGT steering rack will work. If you reuse your LGT rack you won't need a steering column adaptor. I believe in the 99 LGT and 04 WRX the steering rack is the same speed: 16:1 (not too fast, not too slow).

2. You can reuse whatever exhaust is on the 04 WRX wagon. The midpipe will need to be extended a couple inches, any welding shop can do that for you. Or you can get aftermarket 04 WRX exhaust, same thing about it needing extending.

mike-tracy
08-19-2021, 02:56 PM
I used Iwire for the wiring conversion. They took $1200 of my money and merged my car and the wrx's harness together. It may seem unnecessary, but if you haven't done a subaru swap before, the wiring is the make it or break it part of the build, since the mechanicals all bolt up. My friend spent 6+ months troubleshooting his home built wiring harness, while I was out enjoying my car.

twistedsymphony
08-19-2021, 03:07 PM
Thank you so much for the clarification!

I'm honestly not too worried about the wiring. I've got a lot of electrical experience and I'm usually the guy my friends call when they need their wiring worked out.

The biggest thing for me will be that exhaust since I've not got much welding experience, nor am I confident my fat-ass could get under the car to mock it up.

Are there any other parts you think I'll need to source that I can't steal from the WRX?

mike-tracy
08-19-2021, 05:51 PM
If you can do the wiring, then the WRX will have everything you need. Once the car runs, you can drive down to the local muffler place with just the downpipe installed and they'll weld in a couple inch straight pipe, and adjust the hangers to fit. It's really not a big deal.

mike-tracy
08-19-2021, 05:53 PM
My friend put the wiring details in his build thread:



https://sl-i.net/FORUM/showthread.php?18817-Alphius-s-1999-Legacy-GT-WRX-swapped-7-16-STI-6-speed-swap&highlight=Alphius

twistedsymphony
08-19-2021, 06:41 PM
My friend put the wiring details in his build thread:



https://sl-i.net/FORUM/showthread.php?18817-Alphius-s-1999-Legacy-GT-WRX-swapped-7-16-STI-6-speed-swap&highlight=Alphius

Thanks for that lots of great info in that thread.

Also I'm looking at the wiring spreadsheet right now and that looks way easier than everyone makes it out to be. :thumbup:

mike-tracy
08-19-2021, 07:04 PM
3553

The wiring part is easy if you don't screw up! Here's a harness Alphius helped me with: h6 EZ30D 5mt swap into an 03 baja:

lord flashheart
08-21-2021, 03:44 PM
Yea this forum has been a little slow for a while, but the best way to change that is by interacting with other and posting things about your build.
Yea for the most part subaru swaps are pretty strait forward, the thing that hems up most people is the electrical, but if you feel confident about that and your patient/diligent then you'll be fine.
i made a wiring diagram using the one provided by AEM for my ECU, and the one from subaru.
Good luck, research and post your questions, ill try to help when i can, i know the others will too.

twistedsymphony
08-21-2021, 08:49 PM
3553

The wiring part is easy if you don't screw up! Here's a harness Alphius helped me with: h6 EZ30D 5mt swap into an 03 baja:

I do the exact same blue-tape labels when I do harnesses too.
the last swap I did the electrical on required some custom circuit designs to handle signal conversion of the tach and speedo, plus inverting a bunch of relay triggers and building a custom fuse panel since I needed more circuits than the original fuse box could handle.

From what I'm seeing of the Subaru swap wriing: Having to pull the dash is annoying but it's just re-pinning and matching up wires. Time consuming for sure, but easy to do.

mike-tracy
08-21-2021, 08:55 PM
It sounds like you got this. Just make sure you compare an 04 WRX wiring pinout to Alphius's work. I remember there being a couple minor but crucial differences.

twistedsymphony
09-07-2021, 11:33 AM
I a minor update. the deal I was working to buy the 04 WRX Wagon fell through, but on the bright side I found (and purchased) an 04 Forester XT to use as a swap donor. I started a build thread: https://sl-i.net/FORUM/showthread.php?20255-twistedsymphony-s-2nd-Gen-Legacy-GT-Wagon&p=288748#post288748