Carbon Driveshafts: lets talk!

I have the MFactory v3 CFDS for the MT.

Installed may 2023. Has 5k miles on it. No track days.

Impressions:
- No NVH up to 150 mph.
- There's more whiplash when hitting the gas as well as some slight forward whiplash too when letting off the gas.
- Because of this whiplash there's also a bit more tire shirp going into 2nd and 3rd gear.
- No noticeable accelleration gains.
- Saves 10.4 static lbs off the car.
- Saves another 7 lbs of rotational weight (assuming the 10.4 lb is saved at the DS diameter of ~5", a tire diameter of ~25" and diff ratio of ~3.6).

I installed it myself and am so happy I did as opposed to have a shop doing it. It was an incredibly satisfactory install. It probably took me an accumulated whole day (24 hrs) to do it. I fixed the following other things while under there such as transmission mounts, ceramic painted a new set of heat shields, ceramic painted the crosspipe running under the DS, installed new flange bolts and discovered my rear diff bolts had not been tightened to torque spec when I had the solid subframe bushings installed 1/2 year earlier.

All in all, IMO, this CFDS is a quality product with admirable attention to detail.

cmichaelo wrote

I have the MFactory v3 CFDS for the MT.

Installed may 2023. Has 5k miles on it. No track days.

Impressions:
- No NVH up to 150 mph.
- There's more whiplash when hitting the gas as well as some slight forward whiplash too when letting off the gas.
- Because of this whiplash there's also a bit more tire shirp going into 2nd and 3rd gear.
- No noticeable accelleration gains.
- Saves 10.4 static lbs off the car.
- Saves another 7 lbs of rotational weight (assuming the 10.4 lb is saved at the DS diameter of ~5", a tire diameter of ~25" and diff ratio of ~3.6).

I installed it myself and am so happy I did as opposed to have a shop doing it. It was an incredibly satisfactory install. It probably took me an accumulated whole day (24 hrs) to do it. I fixed the following other things while under there such as transmission mounts, ceramic painted a new set of heat shields, ceramic painted the crosspipe running under the DS, installed new flange bolts and discovered my rear diff bolts had not been tightened to torque spec when I had the solid subframe bushings installed 1/2 year earlier.

All in all, IMO, this CFDS is a quality product with admirable attention to detail.

Almost same experience for me. Have the YFCM V2 driveshaft. Had it for a long while, but installed a few weeks ago, before going to the Nürburgring.

Might have some vibration between 150 mph and 165 mph, which then goes away. Not sure if it's because of the drive shaft though, as it could be aero related, or something else.

I feel a better connection with the car through the gas pedal. Not sure if I would spend this kind of money on an upgrade like this again, but it's always cool to have upgraded, lighter parts.

Another M4 F82 cf shaft installed on m3 e92:

Track/S wrote

Another M4 F82 cf shaft installed on m3 e92:

Can you even get these new anymore?

Also, what do they weigh?

..and do you know how they are constructed? Like,
- are the flanges CF too
- are the flanges bonded to the CF tube or is there some locking mechanism?

cmichaelo wrote

Can you even get these new anymore?

Also, what do they weigh?

..and do you know how they are constructed? Like,
- are the flanges CF too
- are the flanges bonded to the CF tube or is there some locking mechanism?

I modify OEM F80/82 axles myself for m2 f87 and m3 e92.

Track/S wrote

I modify OEM F80/82 axles myself for m2 f87 and m3 e92.

Interesting. How much do you charge?

Redd wrote

Interesting. How much do you charge?

1450e with new cv joint.

Track/S wrote

1450e with new cv joint.

Is that with a new or used F82 CF drive shaft?

Redd wrote

Is that with a new or used F82 CF drive shaft?

Used.

Thinking getting yfcm cf driveshaft. I dont do track but just want to stack upgrades on my car for myself lol.
Could we get more updates to owners using yfcm or other cf driveshaft?

There are many threads talking about CF DS. Do a search.

One option I’m thinking about for my 08 M3 that I’m revving and updating with mods. Is it worth getting s CF drive shaft if I’ve not replaced the OEM clutch? Would i even notice any engine response and performance gains?
Or better to do the mods simultaneously?

Yes you will definitely notice gains from CF DS without any other mods.

has anyone had experience with the PST version?

https://pstds.com/product/bmw-e90-m3-mt-dct-carbon-fiber-driveshaft

mikerunt wrote

has anyone had experience with the PST version?

https://pstds.com/product/bmw-e90-m3-mt-dct-carbon-fiber-driveshaft

I have not. Why not get a used f8x CF driveshaft knowing it has gone through BMW development, including bonded joint longevity, and mileage testing? BMW stopped using them, except for in CS models, because the CF driveshaft didn’t fit with the newly required OPF in ~2018. It’s easy for a small aftermarket company to get the adhesively bonded joint thickness and length incorrect as well as improperly designed metallic-to-CF bonded joints, use of incorrect adhesives for long-term durability and improper CF ply angles for torsional stiffness and strength and bending stiffness critical speed failure (8300 rpm redline means you need a very high bending stiffness to prevent an out-of-plane rpm instability bending failure).

M3SQRD wrote

I have not. Why not get a used f8x CF driveshaft knowing it has gone through BMW development, including bonded joint longevity, and mileage testing? BMW stopped using them, except for in CS models, because the CF driveshaft didn’t fit with the newly required OPF in ~2018. It’s easy for a small aftermarket company to get the adhesively bonded joint thickness and length incorrect as well as improperly designed metallic-to-CF bonded joints, use of incorrect adhesives for long-term durability and improper CF ply angles for torsional stiffness and strength and bending stiffness critical speed failure (8300 rpm redline means you need a very high bending stiffness to prevent an out-of-plane rpm instability bending failure).

I hadn’t thought of this, or was aware it was possible.

Is there modifications to the F8x driveshaft for the e90m3? I searched the forum and didn’t see anything specific but I may have missed.

mikerunt wrote

I hadn’t thought of this, or was aware it was possible.

Is there modifications to the F8x driveshaft for the e90m3? I searched the forum and didn’t see anything specific but I may have missed.

I have been doing it for a few years.

Track/S wrote

I have been doing it for a few years.

For personal use or as an item you sell??

mikerunt wrote

For personal use or as an item you sell??

I sell them.

M3SQRD wrote

I have not. Why not get a used f8x CF driveshaft knowing it has gone through BMW development, including bonded joint longevity, and mileage testing? BMW stopped using them, except for in CS models, because the CF driveshaft didn’t fit with the newly required OPF in ~2018. It’s easy for a small aftermarket company to get the adhesively bonded joint thickness and length incorrect as well as improperly designed metallic-to-CF bonded joints, use of incorrect adhesives for long-term durability and improper CF ply angles for torsional stiffness and strength and bending stiffness critical speed failure (8300 rpm redline means you need a very high bending stiffness to prevent an out-of-plane rpm instability bending failure).

E46 guys have been trying to figure this out. One guy has been successful though.

I think this is the least riskiest way to do this.

Track/S wrote

I sell them.

How much? Website?

Bimmer Barney wrote

How much? Website?

PM