One Piece Driveshaft Specs for E92 335i 6MT with E92 M3 DCT Rear Diff

AUbeast86

Sergeant
Nov 6, 2016
268
BFE
I just recently did a metric $hit ton of mods to my car, one being the 6MT and M3 DCT (3.15) rear diff/axles swap. Before anyone asks why I dropped the 6AT after going through all the trouble of finding the 6AT clutch/bushing solution...well it's simple, I'm old school and love smashing gears and old school bitches and old school bitches love stick shifts.

So anyway, I went with DSS for the axle upgrades and the one piece chromoly driveshaft since that's what those hillbilly yahoos over at Motiv run. Up until now, the specs for that driveshaft have been somewhat unicornish in that nobody ever bothered recording them, not even DSS. So, for anyone wanting to do this mod or already has the 6MT/M3 rear stuffs, here are the specs you'll need for DSS to build the one piece unicorn driveshaft for the aforementioned hardware...

1) Overall dimension from the trans output flange (guibo off and in the garbage) to rear diff input flange (6 bolt) - ~1,415mm

2) Trans Yoke - CAPL-4 w/105mm bolt circle diameter and 94mm bolt circle diameter (6 bolt) CV with grease cup. This is an off the shelf part at DSS, however, the 3 bolt holes for the trans side are machined at DSS so the 105mm dimension is critical. It's basically an adapter plate that replaces that hor$e$hit guibo.

3) Rear joint or flange - 94mm 6 bolt CV with hellcap. Same exact CV as the other end except the grease cap is slightly modified so it better fits into the relief groove in the rear diff flange.

4) Material - 3” Chromoly

To keep things as painless as possible, you'll still need to input these specs into their online form since this is still considered to be a "custom" order in spite of the fact that they have now built 4 of these that I personally know of. So don't call them directly trying to do this over the phone. It'll only diminish your confidence in them.

Good luck, Godspeed and may the force prosper your longevity

Pics for fapping purposes...

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Last edited:

derekgates

Sergeant
Feb 23, 2018
386
NW FL
Impressive! That looks like a beefy setup.

I am going M3 rear end with a DCT so these numbers aren't applicable to me but this is fantastic info for the more common 6MT with M3 rear. Looks great!

How has the guibo replacement been? Harsh?
 

AUbeast86

Sergeant
Nov 6, 2016
268
BFE
Impressive! That looks like a beefy setup.

I am going M3 rear end with a DCT so these numbers aren't applicable to me but this is fantastic info for the more common 6MT with M3 rear. Looks great!

How has the guibo replacement been? Harsh?
Thanks! Not harsh at all. No additional NHV but the car is night and day different as far as response and power transfer is concerned. Everything feels much more athletic now.
 

derekgates

Sergeant
Feb 23, 2018
386
NW FL
Thanks! Not harsh at all. No additional NHV but the car is night and day different as far as response and power transfer is concerned. Everything feels much more athletic now.
Incredibly envious! I appreciate my DCT but rowing gears is what I miss with my car. It feels very disconnected most of the time which is a bummer. 6MT with turbos would be a blast.

Thank you for sharing your research with others. :)
 
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AUbeast86

Sergeant
Nov 6, 2016
268
BFE
Is a guibo delete feasible for 6at like if I order driveshaft for my auto is their a simple way to get rid of guibo? Or not worth it for 6 at
Probably not because the problem is a combination of the guibo and the hanger bearing that joins the stock 2 piece driveshaft. However I’ve seen solid guibos for sale before somewhere for pretty cheap so you could easily non destructively experiment with it.
 

derekgates

Sergeant
Feb 23, 2018
386
NW FL
I just recently did a metric $hit ton of mods to my car, one being the 6MT and M3 DCT (3.15) rear diff/axles swap. Before anyone asks why I dropped the 6AT after going through all the trouble of finding the 6AT clutch/bushing solution...well it's simple, I'm old school and love smashing gears and old school bitches and old school bitches love stick shifts.

So anyway, I went with DSS for the axle upgrades and the one piece chromoly driveshaft since that's what those hillbilly yahoos over at Motiv run. Up until now, the specs for that driveshaft have been somewhat unicornish in that nobody ever bothered recording them, not even DSS. So, for anyone wanting to do this mod or already has the 6MT/M3 rear stuffs, here are the specs you'll need for DSS to build the one piece unicorn driveshaft for the aforementioned hardware...

1) Overall dimension from the trans output flange (guibo off and in the garbage) to rear diff input flange (6 bolt) - ~1,415mm

2) Trans Yoke - CAPL-4 w/105mm bolt circle diameter and 94mm bolt circle diameter (6 bolt) CV with grease cup. This is an off the shelf part at DSS, however, the 3 bolt holes for the trans side are machined at DSS so the 105mm dimension is critical. It's basically an adapter plate that replaces that hor$e$hit guibo.

3) Rear joint or flange - 94mm 6 bolt CV with hellcap. Same exact CV as the other end except the grease cap is slightly modified so it better fits into the relief groove in the rear diff flange.

4) Material - 3” Chromoly

To keep things as painless as possible, you'll still need to input these specs into their online form since this is still considered to be a "custom" order in spite of the fact that they have now built 4 of these that I personally know of. So don't call them directly trying to do this over the phone. It'll only diminish your confidence in them.

Good luck, Godspeed and may the force prosper your longevity

Pics for fapping purposes...

View attachment 32366

View attachment 32367

View attachment 32369

View attachment 32368

Sorry for thread necro but this is exactly what I want to do for my DCT M3 setup. Difficult to measure everything DSS needs to do custom build without first using a shortened M3 shaft...

Although when I think about it, I remember the image that was posted in https://www.e90post.com/forums/showthread.php?t=1365817
1583013231760.png


32.75" + 1" center bearing + 24.40" is what my setup would need.



When I tried to get my M3 driveshaft shortened the shop refused the work and stated I need to go with a full custom unit like you have on your car. Big oof.

What was the total price of the DSS shaft? How long did it take to build?
 

iminhell1

Sergeant
Jun 17, 2018
274
Where is flex allowed in the DS?
There has to be an allotment for some. The engine/trans, diff/Rsubframe are not solid mounted and do move.
 

derekgates

Sergeant
Feb 23, 2018
386
NW FL
Where is flex allowed in the DS?
There has to be an allotment for some. The engine/trans, diff/Rsubframe are not solid mounted and do move.
Well this is beyond my knowledge, I already emailed DSS about my situation and asked for either CND'd flanges or a full driveshaft but haven't heard back yet. Trying to figure out what would be the 'next step' :)

What would an allowed flex amount entail? The length of the input shafts into diff and/or the output shaft length from DCT?
 

iminhell1

Sergeant
Jun 17, 2018
274
Well this is beyond my knowledge, I already emailed DSS about my situation and asked for either CND'd flanges or a full driveshaft but haven't heard back yet. Trying to figure out what would be the 'next step' :)

What would an allowed flex amount entail? The length of the input shafts into diff and/or the output shaft length from DCT?
Keeping the stock guibo, or something similar.
Or solid mounting the diff and rear subframe. And some very stiff engine/trans mounts.
 

gmagnus7

Corporal
Dec 3, 2018
154
Keeping the stock guibo, or something similar.
Or solid mounting the diff and rear subframe. And some very stiff engine/trans mounts.
I'd imagine poly engine, trans, diff mounts, and solid sfb would eliminate the need for the guibo altogether. All those things combined would be make it very responsive and immediate feeling. A proper CV is still necessary obviously but the guibo would be useless I think at that point.
 
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Whilst the cv joint looks like a good upgrade over the guibo its damn heavy whilst adding huge amount of rotational mass wich will rob the car of power and torque.

Yes it will be stronger but at a cost and before you say its insignificant we measured it and going from a factory driveshaft to CF mfactory unit its around 10 to 15rwk.

My guibo has endured absolute torture over the last 8 years and shows no sign of wear, maybe just lucky.

But the main reason of the quibo is to stop drive line clunk when on and off the throttle whilst most not having it will develop over time as the car gets older when things
start to wear like cv joints, diff, diff axels cv joints.

It also helps with angle misalignments when things are moving cushioning shock and vibrations between the gearbox and diff.

Its a great idea for a racecar but I would not recommend it for a street car.
 

AUbeast86

Sergeant
Nov 6, 2016
268
BFE
That's fine but people should have all the pros and cons laid out in from of them so they can make their own decisions and how it will effect their cars driveability and performance that's all.
That would be a completely justified comment if I were advocating for people to do this to their car, which I’m absolutely not. I was simply sharing what I did to mine. This mod along with the M3 diff with wavetrac LSD and upgraded DSS M3 axles has completely transformed the car. Ohlins on all 4 corners helps a lot too. Plus there’s plenty of power margin to accommodate these “heavier” components, which was never a concern of mine.
 
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derekgates

Sergeant
Feb 23, 2018
386
NW FL
Keeping the stock guibo, or something similar.
Or solid mounting the diff and rear subframe. And some very stiff engine/trans mounts.
Ah you bring up good points. I didn't think about that.


That would be a completely justified comment if I were advocating for people to do this to their car, which I’m absolutely not. I was simply sharing what I did to mine. This mod along with the M3 diff with wavetrac LSD and upgraded DSS M3 axles has completely transformed the car. Ohlins on all 4 corners helps a lot too. Plus there’s plenty of power margin to accommodate these “heavier” components, which was never a concern of mine.
Oh, certainly. I didn't mean to bring all of this into your thread. I was just curious how much it cost and what the approach was with DSS... There are some good points in here but 'you do you', your car is so sick! I admire it, for sure.
 
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iminhell1

Sergeant
Jun 17, 2018
274
There are CVs on both ends of the driveshaft just like the ones on the rear diff outputs

Ah. I read it I just didn't put it together because there wasn't the traditional boot. Took it as used the CV as a pattern, which was confusing too. LOL

Pretty damn slick design.
 
Oct 24, 2016
1,111
Scottsdale, AZ
Whilst the cv joint looks like a good upgrade over the guibo its damn heavy whilst adding huge amount of rotational mass wich will rob the car of power and torque.

Yes it will be stronger but at a cost and before you say its insignificant we measured it and going from a factory driveshaft to CF mfactory unit its around 10 to 15rwk.

My guibo has endured absolute torture over the last 8 years and shows no sign of wear, maybe just lucky.

But the main reason of the quibo is to stop drive line clunk when on and off the throttle whilst most not having it will develop over time as the car gets older when things
start to wear like cv joints, diff, diff axels cv joints.

It also helps with angle misalignments when things are moving cushioning shock and vibrations between the gearbox and diff.

Its a great idea for a racecar but I would not recommend it for a street car.
We broke two of the Mfactory ones at the aluminum flange that goes to the guibo. We broke one, they said it was a fluke, they sent us another one. That one also broke in the same place. The DSS design is much much stronger and is the only Driveshaft we would run at this point in time. We launched the car so hard that it snapped the Diff cover and bounced the diff off the ground and it did not break the DSS carbon shaft. That is a strong piece. The weight difference between the two is minimal, and having a CV on both ends is EXACTLY what you want in a single piece driveshaft. The DSS costs slightly more, but not much. There are no real drawbacks to the DSS if you want the strongest driveshaft for your build.
 
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