carbon fiber driveshaft

[mitsugsx95]

Does anyone know if anyone makes a carbon fiber driveshaft for the AWD DSM's? Would carbon fiber be the best or is there another material thats better.

 

[Turbo Guru]

I don't know of anyone who makes a carbon fiber driveshaft for our cars. If you are looking to drop some serious coin on driveshaft and CV joints check this place out. http://www.driveshaftshop.com/MITSU.ivnu

Joe

 

[2-0turbo]

Originally posted by Turbo Guru
I don't know of anyone who makes a carbon fiber driveshaft for our cars. If you are looking to drop some serious coin on driveshaft and CV joints check this place out. http://www.driveshaftshop.com/MITSU.ivnu

Joe

Joe, I was not aware of the aluminum shafts for our car. Here is another site, ACPT composites. See an installed shot on Dennis Grant's car at his website. Oh, how I lust after a CF driveshaft! That would be cool. I believe they make 1-piece driveshafts for the AWD for about $2000. Pretty steep.

 

[mitsugsx95]

Thanks for the input. I dont think i have to replace it anytime soon, just wonderin if there were any out there.

 

[Turbo Guru]

Originally posted by 2-0turbo


Joe, I was not aware of the aluminum shafts for our car. Here is another site, ACPT composites. See an installed shot on Dennis Grant's car at his website. Oh, how I lust after a CF driveshaft! That would be cool. I believe they make 1-piece driveshafts for the AWD for about $2000. Pretty steep.

Cool, I wasn't aware someone made a carbon fiber driveshaft upgrade for our cars. However...

Between the $2000 carbon fiber driveshaft and the $1600 aluminum unit (that come upgraded 300m front and rear axles,) I would probably go with the Aluminum unit. There is little torsional difference between the carbon fiber and aluminum units. The CF has the advantage, but only slightly (according to the CF driveshaft manufacturer, "All driveshafts twist to some degree when torque is applied. The resistance to this twist is measured as torsional spring rate. Standard ACPT driveshafts have a torsional spring rate a little less than aluminum and about half that of steel.") Considering that with the aluminum unit comes with upgraded CV axles and is $400 cheaper yet is nearly as torsionally compliant (see above quote,) It would be my choice. One could argue that pinching pennies could cost you in the long-run, but by my guess-timation the aluminum driveshaft is at least 40% more compliant (per above quote) than our stock unit and will give the drivetrain the needed stress relief to avoid unplanned drivetrain dis-assembly. If the CF driveshaft came with the upgraded axles for $2000, I would be willing to fork over the dough (if I thought my car was in need or made nearly enough power to warrant such an upgrade.)

Joe

*edit*
I forgot to quickly mention that I do like the safety standpoint of a CF driveshaft but, on a daily-driven street car it is possible (although not probable) to impact something that would destroy it. On a vehicle that you race it is mandated (I don't recall the requisite e.t.) that you install a driveshaft loop to protect the driver/ vehicle and contain the damage caused by breaking a driveshaft.

 

[2-0turbo]

Originally posted by Turbo Guru

I forgot to quickly mention that I do like the safety standpoint of a CF driveshaft but, on a daily-driven street car it is possible (although not probable) to impact something that would destroy it. On a vehicle that you race it is mandated (I don't recall the requisite e.t.) that you install a driveshaft loop to protect the driver/ vehicle and contain the damage caused by breaking a driveshaft.

Yes, the composite shaft would be quite notch-sensitive, in my opinion. That would suck to trash out your new $2k driveshaft because it has a few rock chips in it! I would hope they have enough margain in their design to account for such damage, though.

The only thing that worries me about aluminum (driveshafts and to a greater degree, flywheels) is what kind of fatigue life do you get from them? Steel can be designed for infinite life if you keep the stress low enough, but aluminum cannot.

Have you calculated the critical speed for our driveshaft? Does anyone know it? Check out this WS6 site , 4th link down on the right under "Drivetrain Modifications". This guys has gone all out on his WS6. He dynos after every modification (!!) and posts the results. A quite informative site.

 

[BoostedDSMman]

If 20 AWD DSMers put down some cash saying that they want a carbon fiber driveshaft from PST, they will make 'em for $1,300. They already make 3000GT/Stealth driveshafts and they are great, no complaints from the owners, check out 3si.org and see for yourself.
Arlene (from PST)said, "As for the shafts for the Eclipses, we have not had enough interest as of yet but if you can get a group of 15-20 people together who would like one, then Mark would consider doing a group buy at a price of $1,300.00 each. Let me know how you make out on this.... toll free 1-888-575-7888." Please help me out, I want one of these shafts like yesterday. Call that 800 number above or email 'em, [email protected].

 

[dsmturboawd]

whats the weight difference?

 

[Morphius]

Originally posted by 2-0turbo
Yes, the composite shaft would be quite notch-sensitive, in my opinion. That would suck to trash out your new $2k driveshaft because it has a few rock chips in it! I would hope they have enough margain in their design to account for such damage, though.

Typical gravel is not going to damage the driveshaft. Carbon fiber is very resilliant to impact loads. If you enjoy running over large rocks or wildlife, then yes, I wouldn't get one.

Downside: It can be a safety issue. When carbon fiber fails, it is a catostrophic failure. Unlike E-glass or Kevlar which will splinter like wood and "pop" strands of fiber. Carbon fiber will explode. Best described as a gunshot.

Upside: Significant weight savings. No creep or deteriation of the material. Less loss of energy.

 

[DSM mechanix]

Originally posted by Morphius
Downside: It can be a safety issue. When carbon fiber fails, it is a catostrophic failure. Unlike E-glass or Kevlar which will splinter like wood and "pop" strands of fiber. Carbon fiber will explode. Best described as a gunshot.

I read just the oposite in an article in Sport Compact Car, they said that a CF driveshaft would "pop" and and-up looking much like a broom...

 

[Morphius]

Originally posted by DSM mechanix
I read just the oposite in an article in Sport Compact Car, they said that a CF driveshaft would "pop" and and-up looking much like a broom...

No, the kevlar, E-Glass or fiberglass will. Carbon fiber splinters. I worked with advaced composites for my graduate studies. Both non-destructive and destructive testing. Samples we tension tested were the diameter of a pencil. The CF will just pop. No warning. It sounds like a gunshot. It left toothpick sized shards lodged in a plywood form that surrounded it, deep enough we couldn't pull tem out.

I've got various pictures I can post of samples. But I'll have to dig them out once I return home after the 5th. I'm out of town for the holidays and my research, pics, etc. is setting in a box back home.

I'll dig them out when I get back. Some pretty cool stuff.

 

[cturok7]

Carbon fiber driveshaft? How strong is carbon fiber? Really? I would go with aluminum.

 

[snowborder714]

Well, they make cars out of carbon fiber, so I'd say it's pretty strong. Plus, with carbon fiber, it is less weight to rotate.

 

[1992awdlaser]

Not sure if it has been mentione yet but a 1 piece driveshaft on these cars are not that great because of the angle.

 

[dsm dork]

I would not trust any company that made a 1 piece driveshaft for 1g dsm's because obviously they didn't do any research.

Unless you're running 8s and have an alum driveshaft and are looking for that last little bit of weight and mass to pull out and thats why you're looking for a cf driveshaft you're just a ricer.