Did a search and found nothing....

So I would like to ask, does anyone have a CF drive shaft for their first gen? Or 2nd even....

I haven't been able to find someone who sells a CF Drive shaft (not like I really need one).

And I was thinking, how would I go about making one? That is of course if anyone here has attempted to make a CF driveshaft?

I've played around a bit with fiberglass, maybe a better next project would be a hood?

Any suggestions, advice, answers? ehehehh

 

A few have beat you to that already...Sorry to burst your bubble .

~T.J.

 

Yeah, the fiberglass hood has been made... though a carbon driveshaft would be nice.....

 

hehehe


https://www.rx7club.com/forum/showth...hreadid=107925

Got a fiberglass one ready to go!!

 

Seems to me that a carbon fiber driveshaft is kind of a pipe dream. You're not going to be able to make it yourself since it needs to be balanced pretty darn well. A shop will likely do it, but it will cost you gobs of cash for very little gain. Hell, the stock driveshaft isn't all that heavy anyway. IMO, very not worth it, invest in exhaust or forced induction first.

 

Balance is the least of your problems.

Carbon fibre is, by nature, fibre. Whenever attaching hard points (like U-joints, f'rinstance) the area has to be heavily reinforced. This is why carbon fibre bodies cars have subframes or metal brackets at points of attachment for crossmembers, etc. to withstand sheer and tension forces.

The driveshaft itself won't neccessarily fly apart, but if your front or rear U-joints keep tearing free, what's the point?

THEN comes the balance issue, very tricky given that you are in essence working with cloth and epoxy resin... with a metal driveshaft you can weld on a balancing weight. How would you affix one to CF and maintain integrity?

 

I couldn't of said it better - So I will follow up by quoting.

 

not really guys acpt.com makes carbon fiber driveshafts.so far the most proff i seen it hold up to is 400 ft lbs rwtq. pipe dream already came true

 

I assume the stock one is steel, does anyone make an aluminum driveshaft?

 

These guys look like they made some nice CF shafts, especialy for that Dump truck! WHoa 114"! That sucker must be something.

I know that A shaft can be made, I'm not asking that... Has anyone tried? But like Manntis said, "Whenever attaching hard points (like U-joints, f'rinstance) the area has to be heavily reinforced".

This is definately the problem area but, I know there is some way to make it work. I just don't know how? I do know that studying up on how to do something before I try is a the best approach. If it all just breaks down to trial and error at some point that is fine, as long as I have some idea of where to start.

Any ideas?

PS: RotorMotorDriver: Burst my bubble? This is'nt a race man, just a project! I know other people have done hoods, but I haven't yet. I like just doin **** for the fun of it!
People always ask me questions like "why are you doing that?" and I just reply, "cause if I don't it would be too easy" I definately like a challenge. OK enough of MY BS! heheh

 

Only the shaft is manufactured with carbon. Not the u-joint flanges. Those items would be machined and then glued to the shaft with epoxy.


You would simply epoxy the needed weight to the shaft. How do you think the 2 halves of a Indy car tub are held together?



******
Sammymatik, The only problem I see is your access to the autoclave needed to cure the resins. This is not needed for building hoods or similar, just for structural items like a drive shaft. Considering your location it may be easy to find someone who would let you clave your part after it is laid up. Give it a shot. let us know.

-billy

 

I have always hear that using the resin as a glue to hold two pieces together is weak because the force joining the two pieces is strictly mechanical and not a chemical bond but, I really don't see any other way to go about it?

Well... I think once I get th cash I'm gonna have to pick me up some carbon fiber, or maybe kevlar. I'll check the properties of the different materials strenths.

That is when I get some cash of course. What I could do if I had a bunch of money for my projects and a nice shop!

 

and how do you measure the weight of the epoxy you're using to affix the balance weight? Gluing two pieces of body together is completely different - the monocoque isn't whirling around at high RPMs where axial balance is critical. And if it IS whirling around at those speeds, axial balance is the least of your worries.

 

yeah it would be rotational balance right?

 

Are you trying to say that the rotational force exerted on a weight glued to a drive shaft is going to be more than hitting a stationary object at 100+ MPH. Get real.
If you are working with carbon you are already measuring epoxy. Would not be that difficult. A monocoque is not a piece a body work.


-billy

 

FWIW many newer pickups and vans have aluminum driveshafts with a carbon fiber shell.

Nice thing about all-carbon fiber drivshafts is that when they break, they don't slice into the cabin or dig into the ground. They just turn into fluff.

 

Slap a too-big glob on, then check balance. Sand the glob down as necessary (without going down to fibers) until balance is within your tolerances.

 

Yeah the saftey aspect is the main advantage, I know an aluminum shaft is pretty damn light. Besides I've picked up some of the stock shafts and they're not all that heavy anyways.

 

Believe it or not, driveshaft tubing is about the same thickness as regular ol' exhaust tubing. Round tubes are QUITE strong in torsion, so they don't have to be thick. Most of the weight is in the yokes and U-joints.

 

How much of a weight savings advantage would there be to a composite shaft anyway? Wouldn't a better place to start saving drivetrain weight be at the flywheel? I could see the composite shaft being great for a drag car or race car, but for the expense or the effort it might not be worth if for the street. Unless your just in it to say, "oh yeah? but do you have a CF drive shaft?" ;D

 

But now that I think about it, on the acpt.com site they have that trash truck with a CF shaft, and I would say that a trash truck has fairly heavy duty job. Especialy for such a long shaft. Also on their site they say that the shaft is great for absorbing vibration

 

Theres one FD I know of that has a Carbon-Kevlar driveshaft...the owner also has a titanium exhaust

For 1st or 2nd gen?! WHO KNOWS! I know I want one!

 

The weight savings is "minimal". The rotating weight savings is also "minimal" since the shaft is so small in diameter.

However, I'd consider it to be a safety issue. Just think about it.... right under your right elbow, the driveshaft is there spinning... in 4th gear it's spinning at engine RPM... just picture that thing coming apart. Or imagine what happens if the front U-joint breaks and the shaft digs into the pavement - can you say "pole vault"?

Now imagine a carbon fiber shaft. It turns into fluff.

 

go grab the cf shaft off the new z and fit it. i saw one the other day and they look nice. oops, off track........

 

Hey a shaft from a Z.... now there's a plan. I just gotta make a quick run down to the dealership huh?