F8X M3/M4 CF Drive shaft mod

[EthanolTurbo]

~1.4 kg (~17%) decrease, which means the radius can increase ~9.8% before the moment of inertia of the CF shaft is greater than the stock one (note that this is just an approximation, as the actual moment also depends on the wall thickness of each shaft).

Elimination of CSB, increased stiffness and net weight savings are still upsides to this mod, but I have a feeling the moment of inertia between this and stock is going to be super close.

I personally hope this mod further decreases drivetrain clunking when shifting at low-medium RPM. Anything else is a bonus. I'm thinking in conjunction with the lightweight single mass flywheel this will increase responsiveness significantly.

[e46IX]

I personally hope this mod further decreases drivetrain clunking when shifting at low-medium RPM. Anything else is a bonus. I'm thinking in conjunction with the lightweight single mass flywheel this will increase responsiveness significantly.

It does increase responsiveness significantly. I have single mass + carbon driveshaft + solid rear end on my e92 m3. It feels like the rear end is bolted to the gas pedal, just going up and down the rev range is a pleasure in itself. once you drive the car set up this way, going back to stock trim the car feels lethargic and lazy.

[Radekxpl]

Any new updates on this new development?😁


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[EthanolTurbo]

Any new updates on this new development?😁


Sent from my iPhone using Tapatalk Pro

Still haven't had time to install and test it, should be done this week.

[Derek //M]

Are the flanges or driveshaft different for a 6sp and SMG?

[Obioban]

Still nobody has installed?

[Altaran]

Still nobody has installed?

Mine is installed and I don't have any issues, but I was only able to drive 30km before I got stopped.

May get around to some more during the next days, I hope I don't get stopped again...

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[Altaran]

Are the flanges or driveshaft different for a 6sp and SMG?

Flanges are the same, there was concern about clearance issues due to the shift actuator sitting directly above. I believe somebody confirmed fitment, but I cannot comment on that since I have a manual.

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[Obioban]

Mine is installed and I don't have any issues, but I was only able to drive 30km before I got stopped.

May get around to some more during the next days, I hope I don't get stopped again...

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got stopped?

[Altaran]

got stopped?

Cops. Here in Germany they like going after modded cars...

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[EthanolTurbo]

Still nobody has installed?

Soon. Should have the carbon driveshaft and carbon roof done next week.

[Projecte46m3]

There are 2 versions of the f8x driveshaft with different lengths correct?. I guess it really doesn’t matter as the driveshaft has to be cut down regardless. A donor e46 m3 driveshaft is needed to source the flanges. Anything else?

Part number 26117855000 is 1477mm in length.
Part number 26107857629 is 1471 mm in length.

[EthanolTurbo]

There are 2 versions of the f8x driveshaft with different lengths correct?. I guess it really doesn’t matter as the driveshaft has to be cut down regardless. A donor e46 m3 driveshaft is needed to source the flanges. Anything else?

Part number 26117855000 is 1477mm in length.
Part number 26107857629 is 1471 mm in length.

It doesn't matter which one you get. One is PreLCI (cheaper), the other is LCI. You can use a donor E46 330i driveshaft or you can splurge and buy new end pieces like I did.

[Projecte46m3]

It doesn't matter which one you get. One is PreLCI (cheaper), the other is LCI. You can use a donor E46 330i driveshaft or you can splurge and buy new end pieces like I did.

Can you share the part numbers for new end flanges? I only see CVJ part number 26117841003. What about the other side that bolts to the guibo? Any other miscellaneous parts needed?

[Nate047]

Cops. Here in Germany they like going after modded cars...

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Are you able to get the driveshaft registered on your papers? I only have a vague understanding of how TÜV works, and what’s allowed as far as custom parts and repairs/upgrades vs tuning parts that are explicitly TÜV approved.