driveshaft

[M33too]

Thanks for the information. It was very helpful.

Originally Posted by ashtaron14

From the Driveshaft Shop

The weight is not the real advantage that Carbon can or will give, in fact any vehicle will see quite a difference when launching.
This is some info we we share on this subject (not trying to sell just letting you know the weight thing is not its real value) what
most don't know is the Carbon end is allot heavier due to the bond area and what you save in the tube sometimes can be given back in
the ends.

Picture (3) 36" long pieces of tube in front of you, one steel on aluminum and one carbon. You pick up the steel tube with your index
finger and thumb and strike it with a screwdriver, this will ring like a bell and resonate for some time. Pick up the Aluminum tube and
you will get about the same, but it will not ring as long or as much. Then pick up the Carbon and it will just make a Click sound when
its struck, you see the material is much better at "NOT" transferring noise/Harmonics from the drive train to the cabin, This may be an
issue if you have a bad Diff or solid or poly mounts in the Vehicle.

The real advantage of the Carbon comes from its Torsional property's, When launching a vehicle either on the street or on the track
something happens that most are not aware of, all Drive shafts will torsionally twist. A steel shaft will twist from 5-7 degrees an
Aluminum about 20 degrees and then you have the Carbon at an amazing 30 degrees. This may not seem all that amazing but what happens
next is, when the steel shaft releases its like a spring unwinding it will come back at the same force and will not only help to break
the tires loose it can also send a harmful shock in to the drive train from this forward to reverse shock. Then we have the Aluminum, it
will twist up the 20 degrees and also releases like a spring but not as harsh or as fast (best bang for the buck as long as the tube will
handle the HP). Aluminum does not transfer as much NHV as steel and its light.

Then we move to the Carbon it will wrap up 30 degrees but its ability after this is what makes it work so well, it will release the
energy over time as it un-winds and will not give the reverse shock of the other materials, in testing what we have found
(this has been proven over and over) is the shaft will slow down the harmful shock that will damage the drive train AND will also
help the 60ft times by not reverse shocking everything its attached to. in private testing we have seen from .1 to .3 gain on 60ft times
depending on the shaft coming off of the vehicle, this will also relate to a smoother drive train, much less harmonic transfer and
be easier on any and all other parts that may not be up to par (weak diff/trans ect) I just wanted to let you know that weight is not
the real advantage here, when comparing shafts take all of this into consideration for a better build.

Now I just need to know if Sedan & Coupe have the same driveshaft.

[ashtaron14]

From RealOEM

[pbonsalb]

Coupe and sedan have same DS but 7DCT and 6MT have 23 mm or about 1 inch difference.

[Hujan]

Originally Posted by ashtaron14

From RealOEM

Originally Posted by pbonsalb

Coupe and sedan have same DS but 7DCT and 6MT have 23 mm or about 1 inch difference.

Well, that's a bummer. As I've said before, you 6MT guys have all the fun. Lightweight fly wheels, CF driveshafts, etc. It's not fair!

[pbonsalb]

Don't worry, DSS will make two versions. They sell 2 lengths for the E36M3, for example.

[squartus]

Hmm im really considering this, if for nothing more than to quite down the solid mounts NVH.
Assume you would prob want to have a professional shop do this install?
Never switched a drive shaft before.

[Hujan]

Originally Posted by squartus

Hmm im really considering this, if for nothing more than to quite down the solid mounts NVH.
Assume you would prob want to have a professional shop do this install?
Never switched a drive shaft before.

That's what I was hoping, too. I love the planted feeling of the solid subframe and diff bushings, but wish I could tone down the diff whine just a bit. How confident are we that the CF driveshaft would dampen some of that noise? If it does, I would do this in a heartbeat.

Originally Posted by pbonsalb

Don't worry, DSS will make two versions. They sell 2 lengths for the E36M3, for example.

Hope so!

[pbonsalb]

Originally Posted by squartus

Assume you would prob want to have a professional shop do this install?
Never switched a drive shaft before.

If you can change an exhaust you can change a DS. I have installed a DSS DS on my E36M3 and it was no big deal. They do use adapter plates at each end but they are installed logically.

[squartus]

Just checked to make sure its rated for 1000hp like the rest and it is... Just placed an order for one. Will let you all know how it works out and how much NVH it removes from having solid diff/engine mounts.

[FazerBoy]

Really interested in this but would like to read a review first before getting one shipped across the pond...

I've got solid diff and subframe mounts.

I have read the explanation posted above by The Driveshaft Shop regarding the benefits of a carbon driveshaft but one thing still puzzles me: how does having a more flexible driveshaft improve acceleration from rest? Surely if the driveshaft spends the first few micro-seconds being twisted instead of remaining rigid and and transferring drive more directly, surely that would result in slower 60ft acceleration?

[squartus]

I think it has to do with keeping your tires from breaking loose right off the line as bad, delivering you the stored power in the drive shaft over a longer period of time instead of all at once.
But im not really getting it for that, but more for the smoother shifts and decreased NHV.

[ashtaron14]

Originally Posted by squartus

Just checked to make sure its rated for 1000hp like the rest and it is... Just placed an order for one. Will let you all know how it works out and how much NVH it removes from having solid diff/engine mounts.

Please keep us up to date. I've been emailing back and forth with DSS and they seemed unsure about the fitment for it. It's just not too reassuring when I keep getting "not sure" and "don't know".

[Hujan]

Originally Posted by squartus

Just checked to make sure its rated for 1000hp like the rest and it is... Just placed an order for one. Will let you all know how it works out and how much NVH it removes from having solid diff/engine mounts.

Awesome! Please do follow up with us you have a chance. I am very interested in hearing your impressions.

Originally Posted by FazerBoy

Really interested in this but would like to read a review first before getting one shipped across the pond...

I've got solid diff and subframe mounts.

I have read the explanation posted above by The Driveshaft Shop regarding the benefits of a carbon driveshaft but one thing still puzzles me: how does having a more flexible driveshaft improve acceleration from rest? Surely if the driveshaft spends the first few micro-seconds being twisted instead of remaining rigid and and transferring drive more directly, surely that would result in slower 60ft acceleration?

I had the same question. You'd think less flex would be desirable, since it would translate more power to the wheels. There must be something we are missing, though, and squartus's explanation below sounds plausible.

Originally Posted by squartus

I think it has to do with keeping your tires from breaking loose right off the line as bad, delivering you the stored power in the drive shaft over a longer period of time instead of all at once.
But im not really getting it for that, but more for the smoother shifts and decreased NHV.

[Richbot]

You're talking about milliseconds here, and milliseconds matter in traction events, because smoothing the force the tire sees is important for maintaining traction, see, for an extreme example, clutch setup in top fuel cars, which is the art of controlling how much force the tire sees, and when, especially over the first 60', which takes about 0.8 seconds in a Top Fuel car. Also in for a review. This is on my list of stuff to upgrade instead of replace when it goes bad

[pbonsalb]

The flex reduces breakage as well, sort of like slicks wrinkling up on the launch. On my turbo E36M3 that makes 609 rwhp and 540 lbs rwtq on a Dynojet in SAE, I have broken two axle stubs and two stock driveshafts at the strip (best trap of 134.54, but best ET of only 11.69 due to launch issues).

[Hujan]

Originally Posted by pbonsalb

The flex reduces breakage as well, sort of like slicks wrinkling up on the launch. On my turbo E36M3 that makes 609 rwhp and 540 lbs rwtq on a Dynojet in SAE, I have broken two axle stubs and two stock driveshafts at the strip (best trap of 134.54, but best ET of only 11.69 due to launch issues).

[ashtaron14]

My Friend's Comment on the subject was "Plenty of Scion FRS Turbo has broken CF DS, I wouldn't recommend it"

I still want one though.

[Richbot]

a turbo FRS probably makes more torque than an NA S65...

[squartus]

Also depends on who makes the drive shaft, you can buy em on ebay for 200 bucks. Drag cars and competition cars use them, high end production cars use them.. Doubt if made by a decent company your going to see any breakage.

Originally Posted by ashtaron14

Please keep us up to date. I've been emailing back and forth with DSS and they seemed unsure about the fitment for it. It's just not too reassuring when I keep getting "not sure" and "don't know".

I just got off the phone with them about my order, said would be 4 weeks before was built and shipped. Usually takes 3 but they are taking a week off for holidays. Said it was on the machine being tested at over 9k rpm as we spoke.
Will get back with everyone with pics/impressions after it gets here.

[dozaiya]

I actually saw the cf drive shaft on the chinese forum - http://club.autohome.com.cn/bbs/thre...5886214-1.html

[BobS]

I hope they make a dct version....i'd be interested

[pbonsalb]

Originally Posted by squartus

I just got off the phone with them about my order, said would be 4 weeks before was built and shipped. Usually takes 3 but they are taking a week off for holidays. Said it was on the machine being tested at over 9k rpm as we spoke.
Will get back with everyone with pics/impressions after it gets here.

Be patient. Last two I ordered from them for other BMWs took 8 weeks each.