6 speed consideration
 

Hi all, i've come across a 6 speed jdm transmission EI-TY856WB-AA. For this particular transmission i'd also get the rear diff, front and rear axles, drive shaft, used clutch, flywheel, pressure plate, slave cylinder. Because this has the R180 rear differential, I need to have the sti's axles as well correct?

Any need for the front axles? This seems to be sold as a complete package, however what else should i ensure or ask to include if available for the swap?

Thanks in advance. Chris

Re: 6 speed consideration
 

Chris,

To answer your question, in addition to everything you listed (minus the driveshaft, you will re-use the SVX driveshaft) you would need a master cylinder, pedal assembly(clutch and brake pedal), and the axles all around. (You can for sure re-use the SVX front axles in the 6 speed trans but you won't be able to reuse the rear axles from the SVX in the R180 because the stubs in the rear axles are different in the R160 vs the R180)

Just a heads up (maybe you have a specific reason to go with this transmission) why pick up such an old 6 speed swap, I mean a version 7 is from 2001, 2002 at best. Just imagine how beat up that thing is and for the price of $3000K, plus I'm sure that doesn't include shipping. There are many swaps listed online some on ebay and many others through the known subaru parts dismantlers (tae, subaru parts, just jap imports,etc..) from early 2004 up to 2008 models that can be had for $3500 shipped. Shop around and good luck.


-Sam

Re: 6 speed consideration
 

Thanks Sam, I appreciate your advice.

I've been researching options on the network and elsewhere and am getting differing results. When using the 6 speed, do I have to use the R180 rear differential? As I understand the R180 is larger than the stock SVX differential (R160) and requires modification to fit. If possible, I'd like to remain with the stock differential.

Re: 6 speed consideration
 

The Rear diff will need to have the gearing match to the transmission, if that is a jdm early version 6 speed it might be 4.44 geared which means you would need 4.44 geared rear diff. And while the R180 is larger and does require a bit of clearanceing it also has mechanical (stronger) LSD

If you get an 06 or newer 6 speed it does use the 3.54 rear diff that the svx has so you could just replace the trans and leave the rear diff stock, That is what I did, however eventually I want the R180 for the benefits I listed.

Re: 6 speed consideration
 

Only the USDM 06 and 07 STi 6MT have a 1.1:1 center differential and use a 3.54 rear differential. That is the only 6MT that would allow you to retain the factory r160 rear diff without changing the gearing in the r160.

The r180 requires such minimal modifications to fit that it is totally worth doing. You will use the STi rear axleshafts with it, which also makes replacing shafts in the future easier than sourcing the correct rear SVX shafts.

You can use the front SVX shafts by adding the stub shafts and seals into the 6MT, although some of the older 6MT already had the shafts in them. Adding the shafts is incredibly easy so that is not a worry.

I used the SVX driveshaft, but I have heard the STi shaft is the same length and works for the swap, best to check the length and confirm. It certainly will make sourcing a driveshaft easier if the STi one is the same length.

Some of the older 6MT are non-DCCD and may be a better option if you do not plan to add a DCCD controller. Although a 6MT with DCCD will work perfectly fine without a controller, you will not get the full benefit of the center diff without it.

As mentioned you will need a clutch and brake pedal set. I used a set from a WRX/STi (mine was an '05 specifically but that whole body range has the same ones). I also swapped the brake booster in from the WRX/STi which made the linkages bolt right up. You will have to cut the firewall for access to mount the clutch master cylinder and will need the line to the slave cylinder. It is a tight fit under there, but after pulling the auto tranny wiring harness back into the car there is a little room at the firewall. I had to modify the SVX gas pedal a small amount just to get it to clear the clutch rod, it just had to be shortened a small amount.

Re: 6 speed consideration
 

Couple of things, from what I see the 08+ Sti continue to use the 3.54 rear diff, problem with them for our purposes the speedometer reading is off the ABS sensors so the 08+ transmission does not have VSS. That being said Mapdccd makes a ABS to speedometer converter. It might be worth it for the extra's that the converter gives you such as the ability to input tire size and have the speedometer read dead on.
As I bolded absolutely I would/will change out my R160 for the R180 when I get funds enough

As to the underlined, No all the impreza line have a shorter wheel base, the sti 6 speed driveshaft would fit the wrx auto trans cars though.

Re: 6 speed consideration
 

Great info guys. I've been researching TAE auto parts and they seem to have a good supply. However, further research has shown that if I were to go with the R180 differential, I would also need the hub/knuckle as well? Apparently the axles associated with the R180 are larger in diameter and require the wrx/sti hub assembly for fitment.

If this is true, shocks and struts would need to be modified as well no? I can't imagine everything else bolting right up to the knuckle.

A quick question on the R180 (3.9 final drive ratio) vs the R160 (3.54 final drive ratio). If I were able to obtain a 2006-2007 6 speed as mentioned above, i could remain with the stock svx rear differential. Will this mean that my final cruising speed would be similar/exact to the auto? meaning, at 60 mph in 6th i'd be at about 2k rpm?

Thinking this through (i am doing a lot of calculations and reading, while writing this)...the rear differential associated with the 6 speed is the R180 with a 3.9 final drive ratio, however effectively 3.54 due to the 1.1:1 center differential, correct? So then i'd have two options, remain with the stock svx differential and if i so choose down the road go with the 180 which would require modification for fitment and the WRX/STI axles, correct?

Re: 6 speed consideration
 

if you had a wrx and went to the R180 you would then need the sti knuckles/hubs, but not so with the SVX this car already uses the larger 5x114.3 hubs. the sti axles will slide right in just as if you put them in the sti hubs, (just a side note our rear hub bearing is the same bearing the sti uses)
As to the rest of your questions/comments.
No need to change suspension, as the svx hub will work, in fact putting the sti hub in would be very very difficult and probably require extensive machining.
and to the gearing vs rpm you have a couple things off, the sti 6 speed uses a final drive of 3.9 but the 06 and up do this by using a 3.9 front diff, a 1.1:1 center diff and a 3.54 rear diff. the 04-05 used a 3.9 front 1:1 center and 3.9 rear. so no the svx won't have a 2k rpm at 60, but its not far off either. here is my car after the 6 speed swap. this is a long video you don't need to watch all of it I will have it start near the appropriate place.
well it doesn't seem to want to work here so here is the link, I suggest looking from about 10 mins on for some typical highway speeds. https://youtu.be/02v8SMjL4WM?t=11m21s

Re: 6 speed consideration
 

The 2007/2006 6 speeds I am coming across are rather high miles (120 - 150k).

I've also come across a 2012 6 speed (Code: TY856UW1MA), this should still allow me to keep the svx differential correct? There's so much information on the net that this gets pretty confusing, because the same transmission code is associated with 08 and 09 6 speeds apparently? Does the 2012 have a higher gear ratio? I understand i'll have to sacrifice some RPMS for casual driving, however I am not looking for a screamer, i.e. 2700 rpm at 60 mph.

So it looks like the 2012 rear ratios are as follows:

1st - 3.636
2nd - 2.235
3rd - 1.521
4th - 1.137
5th - .971
6th - .756
Reverse - 3.545
Final Drive - 3.9
Center Differential - 1.103:1

Will this center differential throw everything off?

Re: 6 speed consideration
 

One issue with the 08+ 6MT is they do not have any provision for the speed sensor on the transmission. Those vehicles use the ABS rings on the wheels for speed. So you will not be able to connect the speedometer and the ECU will not have any speed input.

Re: 6 speed consideration
 

As Tireiron stated, the only hiccup with the 08+ 6MT's is the lack of a speed sensor, however a quick and cheap fix is this ABS to VSS signal converter. http://mapdccd.com/vss.html Just splice a handful of ABS wires at the computer under the passenger seat and tap the signal into the VSS wire on the ECU and done. It's about a 1 hr job with the hardest part being removing the seat and pulling the carpet up and re-installing. HAHA:D

I for the longest time tried sourcing an 07 due to the taller gearing and the benefit of the speed senor, however they were all 90K and above. I ended up going with an 08 6MT, 78K miles.

Re: 6 speed consideration
 

That center diff is close but it may not be the same, What will need to be checked is what the rear diff gearing is for the 2012
I am thinking it won't be 3.54

also I got very lucky when I bought my 6 speed, I got it from a local subaru group member who was doing something drastic, making his wrx into a drag track car with an auto trans, he had bought this 07 6 speed a few years before and had bought it NEW when I got it there was only at most 12k miles on it.