5mt to 6mt swap question

[tylerkroh]

Ok im sure someone will chew me out on this but I cant find a thread devoted to this topic. i was thinking of a 6mt swap into my 00 legacy gt 5mt, I do know that all the EJ engines bolt up to all EJ trans.(atleast thats what i have read) and im sure i would have to change the VSS and differential to the 3.90FD because i have the 4.11 but some of my questions are:

Would i need to do anything to the driveshaft at all?
Would i need a different crossmember to hold it up?
Would i need different axles?
What is the difference between the A.P. Suertrac system and the Helical LSD sytems and which is better?
Also as far as i know my center diff is a 50:50 split and the trans for the 04-05 STI are 35:65 is that front:rear or opposite?

I just like to make sure of things like this because this is my daily driver and i can only have it out of commission for a day or two at a time until i get back up to school. Thanks

[chuckthefuk]

You should read PHATsuby's MR thread. He goes into detail about doing a full conversion on his BE.
viewtopic.php?f=6&t=21454 (http://www.sl-i.net/FORUM/viewtopic.php?f=6&t=21454)

1) Would i need to do anything to the driveshaft at all?
--> You will need a 4EAT (auto) driveshaft. Check PHATsuby's thread of the correct one.

2) Would i need a different cross-member to hold it up?
--> Yes. Now that being said 99% of the time who ever sells the 6MT will provide the x-member or it will still be attached to the 6MT.

3) Would i need different axles?
--> Fronts No. IIRC 05+ sti used female axle splines so if you choose this option you can convert to male stubs.
--> Rears Yes if you want the R180. No. if you want to keep the R160 .

6) As far as i know my center diff is a 50:50 split and the trans for the 04-05 STI are 35:65 is that front:rear or opposite?
--> The split you speaking of is the 1:1 with 0 step up/down.
--> The 2004/05 STi is 3.90 f/r with 1:1 center diff. Simple easy.
--> The 2006+ STi uses 3.90 f & 3.54 r with 1.1:1 center diff. Not so easy.

Stay away from 06+ it complicates things.

-Chuck

[tylerkroh]

Yea ive been following his post i love what hes doin but i knew he was having problems with the driveshaft and can you school me about R180 and R160 as in what these codes are and the differences pros and cons and just to be sure the 6mt crossmember that would come with the trans would fit with no mods? Thanks a lot for the info.

Edit:
Ok so i found this after i looked through his thread again "I did my original 6mt swap with a 2004 Sti tranny and my 2001 auto driveshaft, no problems." So that sounds pretty straight foreward to me. I also realized that the R180/R160 seem to be the diff codes. To my knowledge the diff in my car is a 4.11 and the center diff of the 6MT is a 3.90 so would i have to get the R180?

[chuckthefuk]

1) R160 vs R180
--> R160 came in almost every 5MT subaru.
--> R180 came in every USDM 6MT subaru (Not sure about Spec B)
--> 160mm vs 180mm.
--> R180 uses larger axles and supports higher tq load.. still not a good option for drag launching..
--> R160 uses smaller axles and will not fit the STi rear hubs + brembo swap.
--> 5MT or 6MT rear x-members will hold either R160 or R180

2) 6MT x-member.
--> yes it will bolt up to any 5MT equipped subaru. 1990+

3) DCCD
--> Driver Controlled Center Differential.. Changes 50/50 split..
--> OEM DCCD controller needed to make this work.. Pain in the ass to get it working + you need the sti gauge cluster.
--> Aftermarket DCCD controller available @ $450-1300 depending on company / specs.
--> Without a DCCD controller the diff stays OPEN and 50/50 split is constant.
--> DCCD makes 6MT fun!!

4) Clutch/Flywheel/etc
--> You should match 6MT components with 6MT components but items like flywheel, brake booster, slave cylinder, clutch lines & pedal can be reused from the 5MT vehicle.
--> Items like clutch fork, clutch, release bearing / pilot bearing,

5) 6MT shifter + linkage/
--> Completely different.
--> Has the Reverse gear lockout push thingy + cable.

Here is some reading material.
http://forums.nasioc.com/forums/showthr ... ?t=1412230 (http://forums.nasioc.com/forums/showthread.php?t=1412230)
In that thread in the first post at the bottom are more threads that go into detail about ratio's compatibility and part differences.. None are specific to the legacy chassis but the only issue you have to deal with is the driveshaft compatibility.

My experience with 6MT swaps are as follows.
- 97 LGT with a complete 04 STI power/drivetrain!! EVERYTHING!!. Needed custom driveshaft / 4EAT driveshaft.
- 01 RSTi with a 04' 6MT, shifter + linkage, 6MT driveshaft (this is GC impreza), R180, 04' rear axles, hubs, brembos,.

[tylerkroh]

I didnt see this when i edited my post above lol, but would the larger axles fit into my stock hubs or would i need to upgrade them aslo? The DCCD sounds sweet but it seems a lot of people have trouble putting in the STI gauge cluster and im not very knowledgeable about modding things yet hopefully i can learn more about that before i get to do this.

[tylerkroh]

ok after reading a bit ive come up with a small list that i would need please let me know if i make a mistake here: 04 sti 6MT trans, 4EAT driveshaft, swap the 4.11s out of my diff to a 3.90 which would allow me to keep the axles and brakes etc stock, the 6MT trans X-member, i keep my flywheel but get the 6MT clutch,fork and bearing and shifter linkage. I think that is everything besides the DCCD which as of what it sounded i can do without until i can mess with that.

[chuckthefuk]

The fronts will fit.. if u choose a 2005+ 6MT you will have to change to axle stubs which is not that hard.

If you are talking about the rears then its up to you.

1) Swap R180 and 04' hubs + brembos + 04' Axles

or

2) Keep R160 and leave all your stuff alone. (driveshaft will bolt up)

As I said above ditch the OEM controller and cluster and just go with an aftermarket unit that just need a few signals to activate the center diff.

And yes the combo you listed above will work. I would like to add that the linkage and shifter usually come with the 6MT in most cases unless the seller is "stin-gee".

-Chuck

[tylerkroh]

ok i think thats all my quetions thanks a lot chuck.

[chuckthefuk]

Cool beans.. now stop quoting me each post, its just the two of use here... quoting is for multi-member conversations.. :-D

Cheers and enjoy SLi
-Chuck