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Since this seems to be a common question, I figuired I'd start a new thread with a comprehensive list. This applies specifically to a USDM WRX -> USDM 1st gen Impreza, but should give you a very good idea of whats involved with swapping just about anything else.

Here's what you need:

-Motor (Complete, intake and exhaust manifolds, IC, turbo, etc-obvious stuff ;) )
-Crossmember (You can use the USDM WRX or STi X-member, but you will have to shim your control arms. The only direct bolt-on x-members are the true GC8 ones and the USDM Legacy turbo ones)
-Front Sway Bar (USDM WRX wagon if you're using a WRX or STi x-member, Legacy turbo or true GC8 bar if you're using the respective x-members)
-Full Exhaust (anything for a USDM WRX should work, some fit better than others)
-Fuel Pump (Need at least a USDM WRX, I'd recommend a Walboro 255lph unit, because you'll probably need more fuel eventually :devil: )
-Fuel Pump Controller
-Full Wiring Harness (This is everything from the harness on the intake manifold to the connectors for the o2 sensors, MAF, ECU, etc, to the plug in the rear harness for the fuel pump controller)
-WRX MAF sensor
-WRX o2 sensors
-WRX ECM
-WRX Powersteering assembly (You need the pump, remote reservoir, and the lines that connect this to the steering rack)
-WRX throttle cable (You need this for a perfect fit if you're swapping a car that was not DOHC from the factory)
-Clutch (If you're re-using your factory NA transmission, you will need to re-use your NA flywheel as well, and get an upgraded NA clutch. I'd recommend a ACT or Spec clutch, I've heard good things about the AST ones too)
-Boost Control (Simplest is the factory boost solenoid w/ ristrictor pill, but if you plan on using certain aftermarket ECU management tools, like the UTEC, you can use the GM factory boost solenoid. It's a 3-way device found on the Typhoon and other forced GM vehichles.)

And thats about it... I am working on a full-writeup that I will post someday :rolleyes: but that's it for now. Figuire on spending $2,500-$4,000 in parts. If you can't do the install yourself, factor in about $1,500-$3,000 in labor, depending on who you bring your car to.

-James

ECS

For people that need a DBW pedal, the OEM part # is 36020AE130, cost is about $10
 

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Discussion Starter #6
myfirstdeuce said:
radiator hoses if you are using the RS radiator. Front sway mounts (ones that go over the bushings.
Yes, you will need a lot of new hose. Your old heater core hoses won't fit anymore either. I'd just consider this a misc. cost, like fluids and such.
 

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will98rs said:
what control arm exactly is a bolt on?
you can also use the usdm wrx crossmember, lower control arms and fsb, u just need to swap in yur old rs rack for the wrx one. the splines don't match up. i used this setup in my car since it just came right out of a wrx assembled and all i had to do was the rack swap.

a few things to keep in mind and make sure you remember for ppl who plan on doing this. when the steering rack comes out and your steering column is just hanging there go to extra lengths that those rubber and plastic grommets that hold the steering rack in the firewall don't come out!!!! if they come out you will wish you had the end of a gun to chew on.

i'm using stromung divorced dp, stromung high flow cat, and spt bosal wrx cat back. its all 3" stainless so its not really meant to fit under yur car so while you have no exhaust on trim your heat shielf or bend it outa the way or chances are it will rattle a little (mine does). also the wrx bumper skin comes down way farther so my SPT tip wanted to sit about 2 inches into where ther was bumper. so i needed to shim the braket that unbolts with a pack of large washers (about 3 1mm thick washers between the braket and the chassis on each bolt) and i had to bend the hangers on the exhaust can. this was simple. i just put my knee on the can while it was laying on the grass, put a deep socket over each hanger with a long extention on the end, put my foot on the other hanger and bent each one up. it was trial fitment and small incriments that allowed me to get the space between the bottom of the bumper and the exhaust tip i wanted. the rubber factory hanger will be stretched and tweeked a little since the hangers on the exhaust can are now sitting a little closer to the can but it holds fine and actually stiffens them up so it doesn't wobble around as much.

when you take the crossmember and lower control arms and everything out make sure you mark your camber bolts and try and keep your steering rack centered. the closer you are to centered and having the camber bolts oriented the same as before when you goto put everything back together the closer you will be to having the correct toe and camber. mine is way off cuz i forgot to do this and the car almost pulled me off the road violently a couple times when i drove it tonight to make sure it ran fine.

when you put the tmic on get someone to help you. i almost had a hernia trying to get it in there alone with that rock hard y pipe hose off the turbo inlet. james if you need any help with that write up or want some of the things i made a note to look out for lemme know, i'm more than willing to share my experience to help out future swappers.
 

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RSEnigma said:
a few things to keep in mind and make sure you remember for ppl who plan on doing this. when the steering rack comes out and your steering column is just hanging there go to extra lengths that those rubber and plastic grommets that hold the steering rack in the firewall don't come out!!!! if they come out you will wish you had the end of a gun to chew on.

when you take the crossmember and lower control arms and everything out make sure you mark your camber bolts and try and keep your steering rack centered. the closer you are to centered and having the camber bolts oriented the same as before when you goto put everything back together the closer you will be to having the correct toe and camber. mine is way off cuz i forgot to do this and the car almost pulled me off the road violently a couple times when i drove it tonight to make sure it ran fine.
LOL you lost a steering rack bushing too? That sucked!! I had to go and get a new one while driving it around w/o it.

I didnt have any problems with my alignment as much.. I didnt mess with the tie rods, and if you forget to mark the camber bolts, as I did, I just assembled the strut, and rotated the camber adjust bolt so you could see the hub moving out and then in as you rotate the bolt. Once the hub was all the way in and started to move out again, I stopped and backed it up a bit. Did this on both sides, and it is pretty good. You should get an alignment anytime you mess with the suspension anyway..

Also when removing and reinstalling you new PS hardlines, be very careful. Very easy to strip. If you do strip, or Xthread, you can remove the hardlines from your new WRX PS setup using channel locks. One can be swapped from your old RS setup straight away (same piece) IIRC. The other fitting / hardline can be replaced for under $5 from a hydrolic supply store. Not that I had to do that or anything :(

Also when you get stuck, take a step back, maybe a day or two off. And go back. At one point I had the fuel pump wired backwards which set me back like a week because I had no idea why It wouldnt run "???". And the other weird thing was I had to swap a couple alternator wires because my alt wouldnt charge. Still dont know why.. but it works and sounds great, besides the non-functioning gas light. :) If diy, its a great learning experience, can be alot of fun, but you might have a couple of gremlins. Good luck.

Randy
 

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i thought by using a WRX crossmember with WRX control arms you are dramatically changing the front suspension geometry. I thought it dials in way too much negative camber
 

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i also vote sticky--you guys are really cool for sharing your knowledge and the problems you have had. i plan on doing this as soon as i can take my car out of service for awhile. i'm not too concerned about the mechanical part, its the wiring that looks hard. im a tech school student right now and i can read a wiring diagram and generally know how a car works but could someone (maybe in another thread) point out the GENERAL process for wiring?
 

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the general idea behind the wiring is you need to cut and label everything RS thats staying in the car that has wiring going to the WRX harness, cut it and label it, then find where the corresponding wiring on the harness is cut that and label it and then solder it back together. thats a very rough and quick idea, there's a lot of other stuff that needs to be done and there are a buncha different ways to do some of the little things that need to be taken care of like the fuel pump controller but i'm sure that will be covered in the wiring write up.
 
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