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Old 11-11-2017, 01:39 PM   #1
Scooby Newbie
Member#: 374438
Join Date: Nov 2013
Default Swapping 2017 STI (2015-2017) 6 speed into 2011 GR WRX

Hello all,

I have a 2011 WRX which is quite modified, built engine with VF52 and lots of bolt ons, makes 325/355 on 93 and 380/400 on e85 measured via dynojet.

I drive it in track days and time attack mostly, some autocross here and there (but its not a competitive setup). My dad and I double drive the car, so we ususally register as two different run groups and switch out, worst case scenario happened this summer where there were only 2 run groups so we basically ran the car on the track all day long except for lunch brake. Used up a lot of brake pad but no issues.

So I blew out 3rd gear after a track day in june 2017, replaced with RA spec 3rd gear (minimally stronger from rallispec) and then my first session out during a time attack competition this september I was taking a turn in 3rd gear, and the engine revved up and the car wouldnt move. I coasted back in 4th gear, trans blown again.

Due to the fact that I track the car often I figured going with the STI 6 speed would be better than paying a lot for stronger 5 speed gears due to the differentials. So I went about searching and found a great deal from a salvage yard in my state on ebay.

I ended up picking up a 2017 STI trans setup from a car they purchased that was totaled due to front end damage with 1200 miles on the car. From the salvage yard I got:

-6 speed trans with trans mount, slave cylinder, and clutch fork
-R180 rear diff
-all 4 axle shafts
-Negotiated them to give me an 08-14 STI driveshaft

All off the 2017 for 3750, pretty solid deal IMO, in hindsight I should have also asked them for the starter and flywheel but oh well my mistake. I debated doing the hub swap too but I already have a decent brake and suspension setup, along with not wanting to redrill my wheels or buy new ones. So I kept the 5x100 hubs.

I ended up buying a new OEM flywheel since I drive the car pretty hard and didnt want to have to spend time getting an old one resurfaced.

I previously had a perrin short throw shift kit in the car so not wanting to downgrade my shift feel I went with the Cobb stage 1 shift package with the shift lever and bushings.

As far as the plans for the DCCD........I went with iWire because I didnt want to do any wiring or have to do extensive internet searches. They have been great and sent me the DCCD pro spider with the usb tuning capability for left foot braking, all the wiring has aready been done so everything should just plug right in.

So on to the work and the ongoing problems Ive faced:

We got everything disconnected in the engine bay and then removed the entire turbo back exhaust to be able to get to the driveshaft and the rear diff and axle shafts.

Once the driveshaft was removed we pulled the trans followed by the r160 rear diff and axle shafts.

We then removed the stock shifter.

R180 and axle shafter were installed in the rear without issue, everything bolted right up with easy fitment. There is a temp sensor at the back of the diff which was cut by the salvage yard. Will probably just leave it.

I had some problems with the axle shaft seals, one of them had the circular clamp come off and I had to get a new clamp to get thick back on correctly.

So we then put in the new flywheel and clutch, and I realized that I needed more flywheel bolts, as the WRX uses 6 and the STI uses 9. I ordered new ones off fastWRX.

After putting in the flywheel and clutch I realized that there is a flywheel/clutch shield which is for flywheel inspection which the clutch/flywheel complex was hitting as this was a different shape than the STI one. I made some adjustments as this is just sheet metal and it fits.

Then I realized that the salvage yard for some reason removed the bracket at the back of the trans where the immobile part of the shifter mates......so I couldnt mount the shifter to the trans. I ripped one off my dad's RS he is STI swapping, and he ordered a new one.

Next, we put the STI shafts in the front of the car, since they were much newer and thicker.......but the only "kind of" fit......and immediately ruined the wheel bearing upon taking the car out for a drive, that was probably stupid but its a learning process. So we replaced the old WRX front axles and that worked fine.

So........I put in a Cobb short throw shifter with all the bushings and modified my old perrin shift knob to fit........not sure if the stock WRX leather shift boot isnt the right size......it fits but fits kinda weird.

Also, there is a ground wire which screws into the trans which wasnt long enough to reach the new trans..............so we took it out assuming everything was already grounded fine. Car runs fine.

SOOOOOOOO IT DOES WORK. Now the longer term problem.......I got a DCCD pro from iWire and had them do the wiring. Ive been taking to Brian from iWire a lot and he is great, always available and will sit on the phone with me while I check a bunch of wires with a volt meter and I send him pictures of the wiring and stuff....but I still cannot get the damn DCCD pro to work. My "auto/manual" switch will not light up no matter what I do even though everything seems to be getting power. Have to troubleshoot more but Ive prob spent 4 or 5 hours of pure time on the trouble shooting..,......tearing stuff apart, taking pictures, checking wires......still no success.

I suppose it may not matter to some people but this is a time attack/track car so having a working center differential matters to me.

Again, the swap works perfectly fine. 2015+ STI into GR chassis. Will try to update again after first track day of the season and will try to if I ever get my DCCDpro working.
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Last edited by EAghost3; 02-06-2018 at 10:03 PM.
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Old 01-31-2018, 08:05 PM   #2
Scooby Newbie
Member#: 435830
Join Date: Dec 2015
Location: Detroit MI
2013 WRX Hatch Ltd


following....anything to update since 11/17?

i've got a 2013 wrx @ 307/320.

im at a crossroads, deciding to build it up like you have or sell it for an STI.
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Old 02-06-2018, 09:56 PM   #3
Scooby Newbie
Member#: 374438
Join Date: Nov 2013

updating now
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Old 03-26-2018, 11:51 AM   #4
Scooby Newbie
Member#: 374438
Join Date: Nov 2013

Original post has been updated.

Still havent gotten the DCCD to work. Have been working on upgrading a lot of suspension parts and will hopefully get this working by first time attack event in 2 weeks
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Old 04-18-2018, 01:51 AM   #5
Scooby Newbie
Member#: 446267
Join Date: May 2016
Chapter/Region: TXIC
Location: Dallas, TX
2014 WRX Premium
Dark Grey Metallic


Did you ever get it working? I'm doing a 2018 swap into my 2014 WRX next week
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Old 05-15-2018, 09:24 PM   #6
Scooby Newbie
Member#: 486015
Join Date: May 2018

Yeah I'm looking to do a 2016 swap into my 2014 wrx and I'd like to see how this worked out. I didn't think of all the smaller pieces you need like the flywheel bolts.
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