F8X M3/M4 CF Drive shaft mod

[EthanolTurbo]

Any new updates on this new development?😁


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

[Radekxpl]

Any new updates on this new development?😁


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[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.

[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.

[heinzboehmer]

~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.

[EthanolTurbo]

Any ability to weigh a stock driveshaft on the same scale?

The stock driveshaft weighed 17.6 lbs without guibo on the scale.

Take these weighs with a massive grain of sale because the weight would change half a lb or more due to me just stepping on the scale with the driveshafts and holding them different ways would alter the weight. Once I find a legit scale I will put up accurate numbers.

[Obioban]

Ok I finally was able to pick up the driveshaft this morning and just got it home.

Looks great, can't even tell it didn't come on an E46 M3 originally. I was able to do an unscientific weigh-in on a basic personal scale so this is by no means calibrated or should be taken as 100% accurate. I will find a legit scale later. The weight I got was 14.6 lbs without guibo.

Oh yeah and I took some pics. Will install sometime this week and take it on my local backroads and do a full writeup.

Any ability to weigh a stock driveshaft on the same scale?

Certainly looks good! Very stock-esque.

[EthanolTurbo]

Ok I finally was able to pick up the driveshaft this morning and just got it home.

Looks great, can't even tell it didn't come on an E46 M3 originally. I was able to do an unscientific weigh-in on a basic personal scale so this is by no means calibrated or should be taken as 100% accurate. I will find a legit scale later. The weight I got was 14.6 lbs without guibo.

Oh yeah and I took some pics. Will install sometime this week and take it on my local backroads and do a full writeup.

[EthanolTurbo]

I think the price I got quoted is $260-280 each, no tax, if I buy all 10 driveshafts. If anyone wants one, send me the dough for yours and I'll go get the whole lot if enough people want one. For obvious reasons I'd rather not sit on all the driveshafts but if I had enough forum members that want one I would be willing to pony up the dough to sit on part of the lot I guess. 😅

[0-60motorsports]

Shipping might be cost prohibitive but I can get a lot of these driveshafts for a good price if I had enough people that want one. I can get 10 or so currently.

Nice, Im in depending on what the price will be.

Edit: does anyone know a shop in Jacksonville FL that can do this job?

[dukeofchen]

Also in depending on price, and local-ish

[Cronenberged]

Depending on price I'm in.

[EthanolTurbo]

So are the f8x shafts going to keep going up? Thinking I should jump on one. Looking to do this on my E90, so I'm wondering if less work is going to be required as it's just one gen off. I would also buy a pre-converted one EthanolTurbo . I don't think any of the shops around here are going to like seeing a BMW as it appears most work on trucks and classics.

Shipping might be cost prohibitive but I can get a lot of these driveshafts for a good price if I had enough people that want one. I can get 10 or so currently.

[Corradoloco]

Thank you very much for the info did you use SMG driveshaft flanges from your OEM driveshaft?

There should be difference between SMG and non SMG driveshaft flanges because of actuator if am not mistaken.

I purchased a used one for the flanges but I’m not sure if it was off a smg or man, they look the same, I kept my original one intact.

[Bimmerdude]

So are the f8x shafts going to keep going up? Thinking I should jump on one. Looking to do this on my E90, so I'm wondering if less work is going to be required as it's just one gen off. I would also buy a pre-converted one EthanolTurbo . I don't think any of the shops around here are going to like seeing a BMW as it appears most work on trucks and classics.