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

AUbeast86

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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.

That's awesome destructive testing data. Thanks for sharing.

Just for clarification though, I opted for the 3" chromoly shaft instead of the CF shaft and exactly for the reasons you have demonstrated. I was still on the fence on the CF stuff and wanted something that was as close to bulletproof as economically possible. My logic was if the driveshaft came in heavier than expected, I'd just up the boost a bit (estimated at less than 1psi) as needed to maintain my desired street power goals, which were only around 650whp/600wtq (ish).

However, I'd also like to add....

335i e92 stock MT driveshaft weight = 22.46kg (49.51lbs)

1583166956876.png



335i e92 custom DSS one piece chromoly driveshaft weight (w/aluminum guibo) = ~32lbs

Price tag was also this, compared to the stock shaft currently at $1445 from FCP Euro...
1583166340058.png


1583168189193.png


So yeah,...you guys can do the math...


 

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AUbeast86

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Ah you bring up good points. I didn't think about that.




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.

It's cool man. No worries. I love good discussion laced with a bit of sarcasm hahaha.

DSS will just want to know what trans you have, what rear diff you have and the dimension between the faces of the trans output flange and the diff input flange. I was working with Ricky but he no longer works there.
 

derekgates

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It's cool man. No worries. I love good discussion laced with a bit of sarcasm hahaha.

DSS will just want to know what trans you have, what rear diff you have and the dimension between the faces of the trans output flange and the diff input flange. I was working with Ricky but he no longer works there.

Awesome. That's not bad. I like the points about the CV axles and the chiming in from @[email protected] ... these are things I didn't quite consider as driveshafts are a bit of voodoo for me (at least for getting them 'correct').

I'll start with shortening my M3 driveshaft and if that works out OK then I will measure the final setup and contact DSS.


Your post is great as it gives me something to shoot for!
 

AUbeast86

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Awesome. That's not bad. I like the points about the CV axles and the chiming in from @[email protected] ... these are things I didn't quite consider as driveshafts are a bit of voodoo for me (at least for getting them 'correct').

I'll start with shortening my M3 driveshaft and if that works out OK then I will measure the final setup and contact DSS.


Your post is great as it gives me something to shoot for!

Make sure whoever balances your modified M3 shaft knows what they're doing.
 

derekgates

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Make sure whoever balances your modified M3 shaft knows what they're doing.

Very true. I've been going through an ordeal finding someone that will shorten it locally. I have a local driveline company that refused the work due to the friction welds on the flanges as seen in the https://bmw.spoolstreet.com/threads/n54-dct-w-m3-conversion.3380/post-90516 thread. They recommended I contact DSS for a custom driveshaft (the local shop can't source the flanges needed), but I didn't know enough details about what to ask for (and haven't heard back from DSS about the project yet). Your thread got me closer, but I don't have all of the measurements just yet; going to wait until I have the M3 parts on (DCT length != 6MT).

For now, @LMB335is is going to assist me with his local shop that will shorten it (like his car). From there I will move onto DSS... I just expect an insane price?
 

AUbeast86

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Very true. I've been going through an ordeal finding someone that will shorten it locally. I have a local driveline company that refused the work due to the friction welds on the flanges as seen in the https://bmw.spoolstreet.com/threads/n54-dct-w-m3-conversion.3380/post-90516 thread. They recommended I contact DSS for a custom driveshaft (the local shop can't source the flanges needed), but I didn't know enough details about what to ask for (and haven't heard back from DSS about the project yet). Your thread got me closer, but I don't have all of the measurements just yet; going to wait until I have the M3 parts on (DCT length != 6MT).

For now, @LMB335is is going to assist me with his local shop that will shorten it (like his car). From there I will move onto DSS... I just expect an insane price?

You are going to have to be proactive with DSS as much as it sucks. I was on them constantly and had to actually design the guibo for it because they sent me 3 with the incorrect bolt pattern diameter. All of that has been resolved now. They got everything we did recorded but they will still ask you for all the measurements for liability purposes.

I posted the price a few posts up. It was only $1047 for the custom one. Save yourself some money and pain and just do it right from the beginning. Short cuts always end up costing more.
 

derekgates

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You are going to have to be proactive with DSS as much as it sucks. I was on them constantly and had to actually design the guibo for it because they sent me 3 with the incorrect bolt pattern diameter. All of that has been resolved now. They got everything we did recorded but they will still ask you for all the measurements for liability purposes.

Yeaaah, I am noticing that. I am sure they are extremely busy as they service quite a bit of vehicles. Sucks to hear about the guibo being incorrect.

I'd certainly go chromoly shaft as well. You replaced the guibo to get rid of the rubber OEM piece; were you tearing them up with the power you are putting down?! :astonished:

I posted the price a few posts up. It was only $1047 for the custom one. Save yourself some money and pain and just do it right from the beginning. Short cuts always end up costing more.

Ooops! I missed the price, my apologies.

I have sunk some money into an M3 shaft and a 335i shaft. The modification is around $150. I am testing the waters with the M3 GWS/M3 GTS (DCT software) switchover. Not as easy to swap in my car due to the computer rejecting final drive ratio. I wish I had gone 6MT with my 335is, ugh. Going to try this out first and then measure everything up if the car behaves; it is now (finally) my weekend car so it can stay down while DSS makes a custom one...
 

martymil

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That's awesome destructive testing data. Thanks for sharing.

Just for clarification though, I opted for the 3" chromoly shaft instead of the CF shaft and exactly for the reasons you have demonstrated. I was still on the fence on the CF stuff and wanted something that was as close to bulletproof as economically possible. My logic was if the driveshaft came in heavier than expected, I'd just up the boost a bit (estimated at less than 1psi) as needed to maintain my desired street power goals, which were only around 650whp/600wtq (ish).

However, I'd also like to add....

335i e92 stock MT driveshaft weight = 22.46kg (49.51lbs)

View attachment 35631


335i e92 custom DSS one piece chromoly driveshaft weight (w/aluminum guibo) = ~32lbs

Price tag was also this, compared to the stock shaft currently at $1445 from FCP Euro...
View attachment 35630

View attachment 35632

So yeah,...you guys can do the math...




The mfactory weights in at 12.1 lbs total so when you consider that against 49 lbs from stock or even 32 lbs from dss its quite a weight saving in rotational mass

I haven't broken one yet but I don't launch at silly rpm's as I can guarantee my gearbox will let go before the drive shaft as its the weakest link.

The mfactory is way stronger than factory but not as strong as dss but thats ok as i rather have cf for everyday use as its not a drag car.

You really have to experience a cf driveshaft before and after to appreciate how much less nvh the car produces
 

AUbeast86

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The mfactory weights in at 12.1 lbs total so when you consider that against 49 lbs from stock or even 32 lbs from dss its quite a weight saving in rotational mass

I haven't broken one yet but I don't launch at silly rpm's as I can guarantee my gearbox will let go before the drive shaft as its the weakest link.

The mfactory is way stronger than factory but not as strong as dss but thats ok as i rather have cf for everyday use as its not a drag car.

You really have to experience a cf driveshaft before and after to appreciate how much less nvh the car produces

Since you are quantifying things with the extremely measurable metric of “way stronger”, I’ll quantity the NHV level in my car by using my wife as the barometer. If she’ll ride in it, it’s acceptable.
 
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[email protected]

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The mfactory weights in at 12.1 lbs total so when you consider that against 49 lbs from stock or even 32 lbs from dss its quite a weight saving in rotational mass

I haven't broken one yet but I don't launch at silly rpm's as I can guarantee my gearbox will let go before the drive shaft as its the weakest link.

The mfactory is way stronger than factory but not as strong as dss but thats ok as i rather have cf for everyday use as its not a drag car.

You really have to experience a cf driveshaft before and after to appreciate how much less nvh the car produces
He is quoting the weight of the DSS Chromoly, not the CF. The CF DSS weighs about the same as the M-Factory and is much stronger for about the same price. But it is a custom piece. They do not have them on the shelf like M-factory. I have 3 of them. one for 6-MT to M3 diff, one for 6AT to M3 diff, and one for Samsonas Sequential to M3 diff, which is unusable because when the diff broke it broke the CV joint. I currently have a DSS Chromoly shaft on the car now as it was quicker to get.
 

AUbeast86

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He is quoting the weight of the DSS Chromoly, not the CF. The CF DSS weighs about the same as the M-Factory and is much stronger for about the same price. But it is a custom piece. They do not have them on the shelf like M-factory. I have 3 of them. one for 6-MT to M3 diff, one for 6AT to M3 diff, and one for Samsonas Sequential to M3 diff, which is unusable because when the diff broke it broke the CV joint. I currently have a DSS Chromoly shaft on the car now as it was quicker to get.

FIFY
 

martymil

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Since you are quantifying things with the extremely measurable metric of “way stronger”, I’ll quantity the NHV level in my car by using my wife as the barometer. If she’ll ride in it, it’s acceptable.

If you need to look up the results of how much stronger the mfactory is over stock there is a thread on it, so yes its way better.

I dont know how the factory shaft came in at 49 lbs as mine weights around 21.6 lbs so from what your saying the dss alloy shaft weights more than stock ?

There was a good article in dragzine about the benefits of cf shaft.


Another good article stating the advantages of cf over alloy.


He is quoting the weight of the DSS Chromoly, not the CF. The CF DSS weighs about the same as the M-Factory and is much stronger for about the same price. But it is a custom piece. They do not have them on the shelf like M-factory. I have 3 of them. one for 6-MT to M3 diff, one for 6AT to M3 diff, and one for Samsonas Sequential to M3 diff, which is unusable because when the diff broke it broke the CV joint. I currently have a DSS Chromoly shaft on the car now as it was quicker to get.

The weight is in the cv joints not the shaft itself, I think you will find the dss cf unit with a cv joint either side will still come in at at least 20 lbs if not more which will still be beneficial over stock if you need that kind of strength.

Most applications would benefit from the weight saving and the strength over stock with the mfactory unit, the weight is in the bearing and without having the DSS unit on the scale we are both just guessing how much of a saving that will be.

No one is disputing the strength of the cv joints but it comes at a weight cost and that has its drawbacks.
 
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Torgus

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I have 3 of them. one for 6-MT to M3 diff, one for 6AT to M3 diff, and one for Samsonas Sequential to M3 diff, which is unusable because when the diff broke it broke the CV joint. I currently have a DSS Chromoly shaft on the car now as it was quicker to get.

Hi Tony! Posting under Chris again I see. Or does Chris have 3 of them? Does he also have a Samsonas Sequential installed on his personal car?
 
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[email protected]

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Hi Tony! Posting under Chris again I see.
If you need to look up the results of how much stronger the mfactory is over stock there is a thread on it, so yes its way better.

I dont know how the factory shaft came in at 49 lbs as mine weights around 21.6 lbs so from what your saying the dss alloy shaft weights more than stock ?

There was a good article in dragzine about the benefits of cf shaft.


Another good article stating the advantages of cf over alloy.




The weight is in the cv joints not the shaft itself, I think you will find the dss cf unit with a cv joint either side will still come in at at least 20 lbs if not more which will still be beneficial over stock if you need that kind of strength.

Most applications would benefit from the weight saving and the strength over stock with the mfactory unit, the weight is in the bearing and without having the DSS unit on the scale we are both just guessing how much of a saving that will be.

No one is disputing the strength of the cv joints but it comes at a weight cost and that has its drawbacks.
Have you weighed both? Because we have. As stated the difference is minimal. Why you are so stuck on this M-factory as being the end all be all when it isn't is a little confusing. Two CV joins on both sides so the driveshaft can have the proper angle is the correct way to build a single piece driveshaft. Ps, both M-factory broke on the dyno, not launching.
 

martymil

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Have you weighed both? Because we have. As stated the difference is minimal. Why you are so stuck on this M-factory as being the end all be all when it isn't is a little confusing. Two CV joins on both sides so the driveshaft can have the proper angle is the correct way to build a single piece driveshaft. Ps, both M-factory broke on the dyno, not launching.

Well I did weight the stock and mfactory shafts and posted the results with pics to back it up never seen any for the dss units to back up their claims

I'm not stuck on it at all and can have any version I want but I rather have the weight saving whilst still being stronger than stock
 

nyt

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He is quoting the weight of the DSS Chromoly, not the CF. The CF DSS weighs about the same as the M-Factory and is much stronger for about the same price. But it is a custom piece. They do not have them on the shelf like M-factory. I have 3 of them. one for 6-MT to M3 diff, one for 6AT to M3 diff, and one for Samsonas Sequential to M3 diff, which is unusable because when the diff broke it broke the CV joint. I currently have a DSS Chromoly shaft on the car now as it was quicker to get.

whatever happened with your nizpro 6at?
 

martymil

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Wait, are you saying you can choose to run any driveshaft you want regardless of what other people's opinions or personal preferences are? Fascinating concept.

If my car was a drag car and ran around on full slicks then maybe I would update to the dss unit but most likely not as I run street tyres or semi slicks so no need.

I've been to the drags, track, skidpan, dozens of dyno runs with no failure on the mfacory cf shaft.

+/- 10hp I run 630 rwhp on 93 or 680 rwhp on e85 on average

Lets summarise the facts from this thread

Until I see a proper pic of the weight on the scale of the dss cf unit I'll leave it out and stick to the facts we have.

pro's of a mfactory cf shaft

Far lighter than stock 12 lbs vs 21lbs stock vs dss alloy unit 32lbs
More power to the wheels
Car will use less fuel
Less strain on the driveline
less strain on the motor
Great NVH suppression

Pro's of a dss alloy unit

Stronger than mfactory (subjective as untested independently)
Better alignment between gearbox and diff (subjective as the guibo fixes that)

Cons of mfactory

not as strong as dss unit (subjective as untested independently)
Alignment issues between gearbox and diff on certain cars (I personally have none or seen any, that's what the guibo is for)

Cons of dss alloy unit

Much heavier (adding 20lbs to total weight of the car)
Higher than stock rotational mass 32 lbs vs 21lbs stock vs mfactory 12lbs
Car will use more fuel
more strain on the driveline
more strain on motor
less rwhp.
Alloy has no NVH suppression


Fascinating concept and I dont need to push my opinion just summarising facts from the pro's and con's provided and let people make up their own minds.
 
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The Convert

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If my car was a drag car and ran around on full slicks then maybe I would update to the dss unit but most likely not as I run street tyres or semi slicks so no need.

I've been to the drags, track, skidpan, dozens of dyno runs with no failure on the mfacory cf shaft.

+/- 10hp I run 630 rwhp on 93 or 680 rwhp on e85 on average

Lets summarise the facts from this thread

Until I see a proper pic of the weight on the scale of the dss cf unit I'll leave it out and stick to the facts we have.

pro's of a mfactory cf shaft

Far lighter than stock 12 lbs vs 21lbs stock vs dss alloy unit 32lbs
More power to the wheels
Car will use less fuel
Less strain on the driveline
less strain on the motor
Great NVH suppression

Pro's of a dss alloy unit

Stronger than mfactory (subjective as untested independently)
Better alignment between gearbox and diff (subjective as the guibo fixes that)

Cons of mfactory

not as strong as dss unit (subjective as untested independently)
Alignment issues between gearbox and diff on certain cars (I personally have none or seen any, that's what the guibo is for)

Cons of dss alloy unit

Much heavier (adding 20lbs to total weight of the car)
Higher than stock rotational mass 32 lbs vs 21lbs stock vs mfactory 12lbs
Car will use more fuel
more strain on the driveline
more strain on motor
less rwhp.
Alloy has no NVH suppression


Fascinating concept and I dont need to push my opinion just summarising facts from the pro's and con's provided and let people make up their own minds.

No one is here to make up their mind. This isn’t a for sale thread. He’s simply saying, “Hey, check out my new mod.” And the rest of us are here saying, “Wow! That’s pretty sick. Good job!”