6 Speed Buildup/Versions Recommendations

[SilverSpear]

Ok, the time has come for me to buy another 6 speed for the SVX, from the US. I am not in a hurry (I am flexible in a 3 months time), just waiting for the perfect price/location opportunity since I have a guy who can ship it for me is located in MA.

I read a lot about the 6 speed with and without DCCD and I want the one with DCCD. I also read about the guy Spiider who sells DCCD controllers for these trannies and I think I am gonna go this way.

Now I understand that there are two US versions of the 6mt DCCD, one which came out in the early 2000" and the other in 2005. I will be noobish in this and say that I discovered that the early 6speeds have a male type centre diff while the newer ones have female type similar to our stock autos.

I have read here and there about detailed swaps and stuff (sicksubie's for ex) and just to make things clear here are the Q's:

1- Can I buy the +05' 6MT/R180/Shifter/Pedals/Fork/Clutch/Slave MC/etc... and use my stock axles? In terms of strength, are the +05' axles stronger than the SVX's?

2- Any difference in performance/strength on the SVX between the early US 6MT, +05' US 6MT? What about the JDM 6MT?

3- Which (OT or YT) version 6MT DCCD do you recommend? In terms of strength and least costly in terms of parts needed to fit it in the SVX? Please take into consideration the interchangeable parts of the SVX.

4- What specific custom (SVX related) bits do I need for my project other than the tranny mount? Any seals/panels/ needed that we usually forget (because of the major parts)? Recommended sources?

5- Any other updated recommendations for the build-up? Anything related to the rear Diff versions?

And YES I have read the How-To Docs, this thread is just a question and parts more specific/refresher/new sources related.

Thanks in advance.

[Sov13t]

I have 04 USDM. The main difference between USDM and JDM are gear ratios, USDM is more friendly to highway cruising (~3k at 80mph) while JDM for high RPM acceleration (drag - i guess). Could be wrong on this.

You will be using STi rear axles, while keeping your front axles stock. I have kept my DCCD disconnected thus far, but am interested in purchasing a unit to manage it.

As far as versions, the SVX in it's stock and even everything that we have had in history of modifications can not even make the 6spd break a sweat... it is a very beefy transmission and per STi guys would require ~600bhp to start entering iffy territory.

Hope my .02 is useful,
-Sov13t.

[SilverSpear]

Originally Posted by Sov13t

I have 04 USDM. The main difference between USDM and JDM are gear ratios, USDM is more friendly to highway cruising (~3k at 80mph) while JDM for high RPM acceleration (drag - i guess). Could be wrong on this.

You will be using STi rear axles, while keeping your front axles stock. I have kept my DCCD disconnected thus far, but am interested in purchasing a unit to manage it.

As far as versions, the SVX in it's stock and even everything that we have had in history of modifications can not even make the 6spd break a sweat... it is a very beefy transmission and per STi guys would require ~600bhp to start entering iffy territory.

Hope my .02 is useful,
-Sov13t.

Sure Sov13t, your assistance was definitely useful. I might also have given you some hints about who provides one of the best aftermarket DCCD controller for the STi (Spiider).

The side of the front axle in the SVX where it meets tranny, is it male or female? Because the early STi gearbox are males and their axles are females. I thought the SVX's axles are males.

[Sov13t]

Oh, if that is the case I guess with 05+ you would be using all 4 sti axles.

Sorry, I guess with 04 it doesn't apply to me.

Do you have any links on this Spiider guy? Does he make units with accelerometers that judge vehicle's force vectors and adjust vehicles power distribution?

[Sov13t]

Found him... looks interesting... might get one towards the end of the month and play around with it. Cheers!

http://dccdpro.com/main/?page_id=17

Will let you know how that goes

[SilverSpear]

Originally Posted by Sov13t

Oh, if that is the case I guess with 05+ you would be using all 4 sti axles.

I meant the other way around

[SilverSpear]

Originally Posted by SilverSpear

I meant the other way around

Ok here is what I mean. The SVX axles are all male (Pic stolen from zombie):

Here is a picture of the 2004 STi 6 speed:

and here is the +2005 STi 6 speed:

You can see clearly that the +2005 STi 6 speeds can use OEM SVX axles whereas pre 2005 cannot.

Any help guys?

[Gamesy]

ummmmm the front svx axels that attach the front diff are female. I remember because of the issue with the the pin i had in when taking my tranny out.
That pic of the svx axels has the axel stub still connected to it. I think all subaru tranny's are male( no pun intended :P) just some people find it easier to just pull the axel stub out with the axel instead of risking mushrooming the pin.

here's a pic

[TomsSVX]

If you get a 6mt that needs male axles...

Go buy a pair of front axle seals from subaru for the SVX 4eat

Remove the axle stubs from the 4eat, install them with the seals into the 6mt.

Its that easy, now you can use the stock front axles

Tom

[Boxersix]

The 04-05 6mt's have the earlier DCCD that can fully unlock, while the later gearboxes have center diffs that have a different internal mechanical transfer that still keeps the torque split going some 35% to the front. in the 04-05's, when you cut the signal to the DCCD the torque is heavily biased rearward, nearly making the car RWD in essence. I drove my WRX/EG33/04-6MT without a diff controller for a few weeks. Can't do that in the 06+ w/o burning up the DCCD clutchpack.

I'm also running the DCCD Pro Delux Auto controller. It is a superb piece for the price and does have yaw/pitch sensing via a 2 axis g-sensor and TPS input. Selectable between an auto or manual mode, and a pot to dial in the aggressiveness of the diff. Jeff(the owner/builder) is a GREAT guy and you WILL NOT find better customer service and support from any other diff controller manufacture. Period. He is that nice of a guy. His units have virtually no flaws. My only gripe is that in my car I get driveline binding at very low turning speeds(parking), but I just solve it by wiring in a switch to the DCCD PRO interrupt wire(also hooked to my shifter and my ebrake to S-flick/rotate the car). I flip the switch when parking and it cuts the DCCD power, thus unlocking the diff and eliminating any chance of binding. It's highly likely that the low speed binding is due to the gearbox fluid I'm running and not the controller itself.

Once moving under power(above ~7mph) it performs flawlessly.


Also the gear ratios between 04-05 and 06+ are different so pick your poison accordingly.

Also 04's and early 05's with the male stubs can remove the male stubs, and use the seals Tom mentioned, to fit male axles.

[BoxerFanatic]

just out of curiousity, and for future reference...

you mention different gearing...

Which is better for the H6? Something that has good pick-up in lower gears, and a nice tall cruise in 6th gear, smooth and easy, like the SVX 4EAT does... That is the one nice thing about the 4EAT... easy quiet cruising in top gear, once it slip-slide-shifts all the way to 4th.

Interesting stuff about the DCCD... sounds kind of like some of the Porsche Carrera 4 models that if you pull up one notch on the e-brake lever, and it dis-engages the front drivetrain for some RWD fun, but not enough up to actually engage the parking brakes at the wheels.

[TomsSVX]

Originally Posted by BoxerFanatic

just out of curiousity, and for future reference...

you mention different gearing...

Which is better for the H6? Something that has good pick-up in lower gears, and a nice tall cruise in 6th gear, smooth and easy, like the SVX 4EAT does... That is the one nice thing about the 4EAT... easy quiet cruising in top gear, once it slip-slide-shifts all the way to 4th.

JDM gearing is close ratio meaning it is a shorter ratio... My 6mt runs about 3800 at 80mph... USDM transmission with the lower gearing is only different in 5th and 6th gears allowing around 3200rpm at 80 if memory serves

Tom

[Crazy_pilot]

All 6MT's have the same ratios for 1-4. The JDM STi has the tightest 5th and 6th, followed by the USDM STi, and the JDM Forester STi has the tallest of all (best for highway cruising). The Legacy GT Spec B's 6MT has the same ratios as the Forester STi, but does not have a limited slip front diff.

IMHO, for the SVX the ultimate is the Forester STi's tranny. However, if you're looking to build a grand touring beast and not as concerned for the ultimate in performance, the Spec B's tranny will do you very well. The Forester 6MT is almost impossible to find though. Since I've known of this I've only seen one drivetrain imported. The Spec B's tranny can be had brand new for something like $3200.

[Boxersix]

Originally Posted by TomsSVX

JDM gearing is close ratio meaning it is a shorter ratio... My 6mt runs about 3800 at 80mph... USDM transmission with the lower gearing is only different in 5th and 6th gears allowing around 3200rpm at 80 if memory serves

Tom

Gear ratios change on 3/4 to space them more towards 5th and 6th gears. Supposed to have made the car "more drivable" but IMO the shorter gears are better.


GR's

04-06

Final 3.9:1
1st 3.64:1
2nd 2.38:1
3rd 1.76:1
4th 1.35:1
5th 0.97:1
6th 0.76:1

+07
Final 3.9:1
1st: 3.636
2nd: 2.375
3rd: 1.521
4th: 1.137
5th: 0.971
6th: 0.756


Biggest difference is the DCCD ratio(due to that DCCD design change i mentioned) which changed in '07 to 1.1:1 so the rear diff went from 3.9 to 3.54 so just make sure you match up the proper R180 if using the later gearboxes. The latest "fad" for the Sti guys is to swap in the '07 gearset. Weaksauce IMO

[TomsSVX]

the reduction is to help keep driveshaft revs lower... Great idea IMHO

Tom