[NISFAN]

Originally Posted by M2C_PLUS

I would be up for this.

Will this be a "plug & play"? ( I haven't read all the posts.

What is the weight difference? (If known yet)

Not known from this manufacturer. However I'm sure they would be able to estimate what a 1400mm carbon shaft will weigh?

OE wise, the F80/2 carbon driveshaft weighs in at 7.76kg vs around 8.85 for a steel one.

I would expect an aftermarket CFDS to be lighter than an OE CFDS, maybe 7.0 dead? So marginally bigger gain for the aftermarket version.

I really don't understand the delay in moving this project forward. The manufacturer is surely only limiting a batch size to 15 to cover his R&D figure. If 10 are interested, then just group the 15 cost together and be done with it. Or collectively buy 15 and put the excess ones in the for sale section. Many folk would like to buy one, but know the flaky nature of group buys, so won't get involved. Different proposition to a ready to roll item.

Alternatively, go local and get an aluminium one done. Similar weight, smaller cost.

[ebisu8]

2 more spots left to get to the minimum of 15 spots. If you're interested, here's your chance.

[ebisu8]

Originally Posted by WagonR

ebisu8 is this cross posted in the N55 subsection? Since it works with the OGs and Comps should it be? Want me to put something in there linking back to this?

That would be quite helpful. I honestly didn't do it because I wasn't trying to spam it all over the place. Thank you.

[GFEA]

Im in. Just making sure this works for DCT; never changed a drive shaft before.

[kvnchu]

whats the weight difference between oem and this? Thanks

[Megator]

Originally Posted by dragonsi

What...? This is about rotating mass, grab your mom's dough roller and spin it, now grab a paper towel roll and spin it. Do you notice anything? I really think you should probably stick with the aesthetics, and buy yourself one of those $40 BMW coffee mugs, to keep at your desk at work.

OMG, please learn to read, and then read all my posts on the 1st page. Then come up with some clever insult and go tell it to yourself in the mirror.

To the ppl saying this is so amazing and your really gonna feel it. I call BS. Why cause 1) the EU spec M3/4 acceleration did not change when they went from a CF to steel drive shaft due to the OPF and 2) I could barely feel a 10kg rotating mass reduction on my 130 engine hp 1 ton Miata.

Will it make you faster? in theory yes, accelerations will be .01% faster. Should it be high up on your list of weight reductions? No, I dont think so, similar amounts of rotating mass can be removed from the wheels/brake discs which also help reduce un-sprung mass.

That is all.

ebisu8 hope you find your last buyer and good luck delivering the product.

[ebisu8]

Originally Posted by Megator

Will it make you faster? in theory yes, accelerations will be .01% faster. Should it be high up on your list of weight reductions? No, I dont think so, similar amounts of rotating mass can be removed from the wheels/brake discs which also help reduce un-sprung mass.

That is all.

ebisu8 hope you find your last buyer and good luck delivering the product.

In my case, I've already done these things. they were the first things I did. Hence my goal to get this done. It isn't for everyone and that's ok, I know there is a market for it and the e9x community proved that. No reason why the M2 FAM can't enjoy this fun mod.

BUMP for the last spot and I welcome anyone else that wants to get in on this as I know some of the already committed will de-commit on this group buy.

[MR RIZK]

Just saying I wouldn't buy a $40 BMW Mug

[Megator]

Originally Posted by ebisu8

In my case, I've already done these things. they were the first things I did. Hence my goal to get this done. It isn't for everyone and that's ok, I know there is a market for it and the e9x community proved that. No reason why the M2 FAM can't enjoy this fun mod.

BUMP for the last spot and I welcome anyone else that wants to get in on this as I know some of the already committed will de-commit on this group buy.

My comments on that weren't for you ebisu8 but the other guy that was being an ass.

BTW mass is only part of the story, the aim is to reduce the moment of inertia. https://en.wikipedia.org/wiki/Moment_of_inertia

The equation for moment of inertia for a hollow cylinder is I = 1/2 M*(R1^2 + R2^2), where R1 and R2 = the radius of the cylinder (inner + outer) or (1/2m*r^2 for thin walled cylinders)

https://efcms.engr.utk.edu/ef151-201...lass-4-3&p=mmi

Note that the radius terms are squared!!! so not only should the drive shaft weight go down but the diameter/radius of the drive shaft must stay constant.

If the radius goes up the moment of inertia change might be a wash with the weight loss. Doing some back of the napkin calculations a 1kg weight reduction (10 to 9 kg) for a 10mm radius increase, results in a mini increase of the moment of inertia...

[PilotxERAU]

What happen to this? Is it still being pursued? I am interested.