Chase's cheap six speed conversion - Subaru WRX Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 58 Old 01-02-2012, 09:55 PM Thread Starter
WRXtuners Member
 
Chase's Avatar
 
Join Date: Sep 2007
Location: Washington
Posts: 978
Images: 2
Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to
Chase's cheap six speed conversion

Figured I'd chronicle this since it'll be a significant undertaking. As I posted on my other thread, I popped the back of my trans off to swap rear Difs, and found teeth everywhere. Ugh... Now I remember why I drove an Sti for two years.

So I want to do this the cheap way. btw, in an 02-05 the swap is much easier, since they already have a 3.54 final rear Dif ratio. This is exactly what you want if you swap in an 06-07 six speed. Plus the clutch slave cylinder stays the same. With the 06, 07 Wrx I need the clutch slave and the 3.54 rear Dif.

The 04, 05 Sti tranny has a 3.90 final drive, which means I would have to source a rear Dif that they never put into a Wrx. Only 2.2 l models got that one.

Also my axles and seals stay the same, the one bonus that comes from an 07.

So here is my to buy list.
06 Sti tranny.
02-05 or Sti slave clutch cylinder. (correct me if Im wrong, but I think the Wrx I is almost the same)
Sti clutch and flywheel and throw out bearing
Sti clutch fork
02-05 Wrx rear Dif (should all be lsd, but I've only had one person confirm that I want lsd not open, advice please)
Sti shifter, linkage, boot and knob
Automatic 02-07 Wrx drive line (was told any Subaru auto drive line will do, advise?)

Feel free to correct, add to or ask questions about my list and plans. The idea is to accumulate the right parts from the start to eliminate down time and wasted money, obviously.

355 awhp fp green six speed wagon in Corvette Atomic Orange
-Brandon
Chase is offline  
Sponsored Links
Advertisement
 
post #2 of 58 Old 01-02-2012, 10:50 PM
WRXtuners Member
 
turmic's Avatar
 
Join Date: Jul 2007
Location: Pennsylvania
Posts: 4,371
Images: 6
turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to
Send a message via AIM to turmic
What's involved with swapping from a 5MT to a 6MT? You will need to obtain and install the following components:
1. A complete 6MT transmission.
2. 6MT transmission mount.
3. 6MT shift knob, 6MT shifter linkage, and 6MT shift boot.
4. The drive shaft from a 6MT or the drive shaft from any model automatic transmission equipped Subaru. The stock WRX 5MT drive shaft may also be modified (will need to be shortened) to fit as well.
5. New rear end options:
a. New ring and pinion gears to upgrade the stock WRX R160 rear differential to 3.90.
b. Convert the 6MT center differential from 1.0:1 to 1.1:1 and use the stock WRX R160 rear differential.
c. Swap out the stock WRX R160 rear differential to a stock STi R180 rear differential.
The real decision to a 6MT swap is the rear differential, as going with the R180, though the "better" choice, raises the costs significantly as you need to use the entire rear end consisting of the STi driveshaft, STi rear half shafts, Sti rear hubs, and STi rear discs to include the Brembo brakes. This will also require the use of 17" wheels as well to accomidate the bigger brakes, which for some, may be an additional expense. As well, www.gearboxtech.com sells the parts that let you use R180 inner CV joints and the R160 outer CV joints if you want to use the R180 rear end and not swap over to the R180 hubs/brakes.

Transmission FAQ: Read if you are thinking of upgrading!

^ That is what the unabomber faq has for information.

Kirt
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae
turmic is offline  
post #3 of 58 Old 01-02-2012, 11:09 PM Thread Starter
WRXtuners Member
 
Chase's Avatar
 
Join Date: Sep 2007
Location: Washington
Posts: 978
Images: 2
Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to
Thanks kirt, although option A for rear ends tells me that that FAQ was compiled before the 06 07's were out. With the 3.54 final out, you have the option to use a r160 without modding it. This makes it much easier, especially for 02-05 owners.

355 awhp fp green six speed wagon in Corvette Atomic Orange
-Brandon
Chase is offline  
post #4 of 58 Old 01-03-2012, 09:18 PM
WRXtuners Member
 
turmic's Avatar
 
Join Date: Jul 2007
Location: Pennsylvania
Posts: 4,371
Images: 6
turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to
Send a message via AIM to turmic
Yeah, unabomber made most of his FAQs before the hawkeyes came out. I've never attempted this modification...so, that's the best I can do for help unfortunately.

Kirt
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae
turmic is offline  
post #5 of 58 Old 01-03-2012, 09:42 PM Thread Starter
WRXtuners Member
 
Chase's Avatar
 
Join Date: Sep 2007
Location: Washington
Posts: 978
Images: 2
Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to
It's all good. I appreciate any input. Hoping to document/ photograph as much as possible so that we have this info first hand on our site.

As of now, I can check the six speed, cross members, fork and rear Dif off the to buy list.

355 awhp fp green six speed wagon in Corvette Atomic Orange
-Brandon
Chase is offline  
post #6 of 58 Old 01-03-2012, 10:37 PM
WRXtuners Member
 
Join Date: Sep 2011
Location: Pennsylvania
Posts: 324
BoostinChick is a helpful contributing member
Garage
List looks pretty good. Only thing left to consider is the DCCD if you want to utilize it, you will have to use an aftermarket solution. I know a few people who have done the 6spd swap in their 06-07 and still on the stock rear diff. I also bookmarked this when I was going through my 6spd vs. built 5spd debate and spending hours of research online. Hope it helps you (Post #20) -
http://www.clubwrx.net/forums/transm...ti-tranny.html

Guy actually put a 6spd in his 06 Wagon.

Quote:
Originally Posted by ansonowicz
Here I was, ready to post my writeup and forum goes down for a few days


Here goes, it's a lengthy read:


The project took approx 1 month. I worked on it for a couple of hours 3-4 times per week. I took my time, examined every single bolt, nook & cranny, measured 4 times before cutting, etc.

Well, that last remark was a figure of speech but this was the first time i've ever attempted anything as remarkable....by myself.

Parts acquired:

- 2006 STI transmission (used, 15k mi, center diff is 1.1:1 ratio)
- 2006 STI driveshaft (used 800 mi, so the seller claimed it was an 06
- STI 6 speed shifter assembly (new)
- STI 6 speed gearshift knob (new)
- ACT STi Streetlite flywheel 13.9 lbs (new)
- ACT Streetlite STI clutch kit (used, 8k mi)
- 2003 Rear Diff (freebee...Thanks ERIC! 3.54 ratio, final drive = 3.9)
- Neetronics DCCD standalone controller (new)
- 2 Circlips for 2006 WRX Front Axles (new, dealer)
- 2 compression washers for clutch master cylinder (new, dealer)
- about a dozen M10 x 1.25 pitch bolts (various lengths for bellhousing, turbo studs, etc) with Lock washers and hex nuts

Parts Re-used:

- Front Axles (2006 axles do not require new seals or stubs)
- Rear Axles
- crossmembers
- exhaust hanger (on transmission)
- all wiring connectors & plugs (except one plug)

- Sandra
2007 WRX TR | Stage 2 | PAR Gearset (Built by AndrewTech)
BoostinChick is offline  
post #7 of 58 Old 01-03-2012, 11:36 PM Thread Starter
WRXtuners Member
 
Chase's Avatar
 
Join Date: Sep 2007
Location: Washington
Posts: 978
Images: 2
Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to
Are you saying you know if people keeping the 06/07 rear Dif with the Sti trans?

355 awhp fp green six speed wagon in Corvette Atomic Orange
-Brandon
Chase is offline  
post #8 of 58 Old 01-04-2012, 11:35 AM
Moderator
 
mosc's Avatar
 
Join Date: Mar 2005
Location: Pennsylvania
Posts: 6,500
Images: 7
mosc is a helpful contributing member
Garage
I wouldn't do it. The 07 WRX rear diff is quite weak. It was a real problem in the 06-07's. We used to argue on here if the rear diff was a greater restriction than the transmission on 06-07 WRX's. Subaru should not have used that diff with the EJ255 and the 08+ is different if I recall correctly. My memory is the 06-07 WRX rear diff is the same one used in the 02-05 EJ205 powered WRX's.

04 STi 16G powered lagless fun
04 WRX: SOLD
mosc is offline  
post #9 of 58 Old 01-04-2012, 06:00 PM
WRXtuners Member
 
turmic's Avatar
 
Join Date: Jul 2007
Location: Pennsylvania
Posts: 4,371
Images: 6
turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to
Send a message via AIM to turmic
If you ever looked at the WRX rear diff and the STI rear diff. You'll notice that the WRX rear diff looks significantly smaller than the STI. So, just like a lot of other things. I'd think the STI rear diff has to be a bit beefer in strength and weight. Or you can just use it until it blows up/upgrade it. Hell, Lil Shoaf and I think Basco upgraded their WRX rear diffs.

Kirt
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae
turmic is offline  
post #10 of 58 Old 01-04-2012, 09:36 PM
Moderator
 
newtothegame's Avatar
 
Join Date: Dec 2006
Location: Maryland
Posts: 6,493
Images: 4
newtothegame is known to be trustworthy and helpful newtothegame is known to be trustworthy and helpful
Send a message via Yahoo to newtothegame
I upgraded mine when I had my tranny rebuilt. My tuner highly recommended it.

**Sorry I was wrong, I upgraded the front in mine. To an Mfactory unit. My rear is stock, and was told it would suffice with my power and goals for the car. I might eventually upgrade it when funds and time are available again.

Joshua
"2007 WRX- PPG'd, 20G- Tim Bailey tuned
Stage 2 2005 WRX
Cobbtuning.com"

Last edited by newtothegame; 01-04-2012 at 09:54 PM. Reason: More info
newtothegame is offline  
post #11 of 58 Old 01-04-2012, 09:50 PM
WRXtuners Member
 
basco's Avatar
 
Join Date: Aug 2004
Location: South Carolina
Posts: 1,873
basco is a WRX expert worth listening to basco is a WRX expert worth listening to basco is a WRX expert worth listening to basco is a WRX expert worth listening to basco is a WRX expert worth listening to basco is a WRX expert worth listening to
Send a message via AIM to basco Send a message via MSN to basco
I upgraded the LSD unit in mine but the ring and pinion and all other bits are factory subaru

FP GT35R MoTeC M800 AndrewTech PPG'd Wagon - 513AWHP
06 Mazdaspeed6 280/330
- Matt
basco is offline  
post #12 of 58 Old 01-04-2012, 10:47 PM
WRXtuners Member
 
turmic's Avatar
 
Join Date: Jul 2007
Location: Pennsylvania
Posts: 4,371
Images: 6
turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to turmic is a WRX expert worth listening to
Send a message via AIM to turmic
So, where is the weakness in them then? The LSD section or the ring and pinion?

Kirt
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae
turmic is offline  
post #13 of 58 Old 01-05-2012, 01:33 PM
WRXtuners Member
 
Join Date: Sep 2011
Location: Pennsylvania
Posts: 324
BoostinChick is a helpful contributing member
Garage
Quote:
Originally Posted by Chase View Post
Are you saying you know if people keeping the 06/07 rear Dif with the Sti trans?
Yes, that is what I am saying. A few people on NABISCO who have done this swap on their hawkeyes have kept their stock rear. I asked specifically when I saw a few 6spd "packages" for sale that were minus the R160 (as I mentioned, I was contemplating this swap for myself). Not sure why, cost savings possibly?

- Sandra
2007 WRX TR | Stage 2 | PAR Gearset (Built by AndrewTech)
BoostinChick is offline  
post #14 of 58 Old 01-05-2012, 09:08 PM Thread Starter
WRXtuners Member
 
Chase's Avatar
 
Join Date: Sep 2007
Location: Washington
Posts: 978
Images: 2
Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to Chase is a WRX expert worth listening to
Huh. Well I am trying to do this inexpensively, I am also doing it right. Otherwise id just be stuffing in another stock five. I don't mind changing the Dif later if need be, but at least for now it is getting one of correct gearing.

355 awhp fp green six speed wagon in Corvette Atomic Orange
-Brandon
Chase is offline  
post #15 of 58 Old 01-06-2012, 06:58 AM
WRXtuners Member
 
Join Date: Jun 2007
Location: Texas
Posts: 4,979
pzr2874 is known to be trustworthy and helpful pzr2874 is known to be trustworthy and helpful
You should put parentheses around the "cheap" part in your title.

I don't see this being very cheap..... lol

Good luck Brandon.

Paul
2002 WRX Sold
2007 WRX Sold
2007 STi totaled
2007 Foz XT sold
2007 MS3
pzr2874 is offline  
Sponsored Links
Advertisement
 
Reply


Currently Active Users Viewing This Thread: 9 (0 members and 9 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome