I ordered a carbonfiber driveshaft from precision shaft technologies last week. It came in today, and I opened it up today to look at my new toy. It had a steel slip yoke instead of aluminum that I ordered, They charged me accordingly, so I figured I'd forget about it. The unit is no lighter than my factory aluminum driveshaft, no sh*t I think it's heavier. I'll have to weigh it and get back to you on that one. Anyway, I tap the ring I'm wearing on the shaft expecting to hear a nice thud. Instead I get a nice metalk ting. I start tapping the length of the shaft, and it is clearly making a metal noise. I run a magnet down the shaft with no response, so atleast there is no steel in there. But then I get out my volt meter and run a test tone with a lead on the slip yoke & a lead on the ujoint.. . . I got a tone, the shaft was passing current, and last I checked carbonfiber or resin do NOT pass current. They're closed till monday, so I have to wait till I can call them and see what the deal is. But When you hold this shaft it truly feels and sounds exactly like an aluminum driveshaft wrapped in one thin layer of carbon fiber painted plastic tape. here's a direct link to the ds in question.
http://www.pstds.com/critical_link_drive_shafts.htm

here's a pic of what I have,


I thought that these guys were a well-known respected company, so I'm completely confused. There is no mention of any metal in the shaft on their website, and none in the conversation I had when placing my order. I ordered a carbon fiber driveshaft, not a partial carbon fiber driveshaft. Anyone in here ever dealt with these guys before, or better; Can any previous owners of carbon fiber driveshafts tell me anything to make me feel better about this. I guess, I'm not asking any real questions at all. I'm just pissed and I can't call pst right now, so I just needed to vent somewhere.


I tried to add the pic as a thumb but I have no idea how. If a mod could do that, it would be greatly appreciated.

 

Carbon fibre will conduct electricity. Years ago some Top Fuel teams used carbon fibre covers to improve aerodynamics around the engines. If the spark plug wires were up against the panels there was a good chance they would cross-fire. It resulted in some pretty spectacular blower explosions.
Use an ohm meter to see how much resistance there is in the shaft. An aluminum shaft would have very little resistance but I think that carbon fibre would show more resistance.
Ken

 

kenova that's news to me, and I have no problem looking dumb if it means I didn't get screwed here. I have been fabbing carbon fiber and fiberglass interior panels for years and have never worried about conductivity, as I always thought there was none. I'm guessing that the conductivity is low since I have never shorted anything out while throwing live wires across panels during installs.

 

when I put the leads on the end yokes I get 7.4 ohms, when I come inward a couple of inches on both sides of the carbon piece I get 80.5 ohms.

 

If you got that driveshaft hoping to save weight, then I'm sorry...there isn't much you can do to be lighter than the coke-can aluminum DS most of our cars come with. I have that EXACT same carbon fiber DS from PST, and it weighed the same as my stock aluminum, only that it is a full 3.75" in diameter, has a Powerglide slip yoke with 1350 joints, and a beefy 1350 joint in the rear. It is way stronger, and has way better vibration damping characteristics.

If you are trying to save weight, concentrate on the clutch/flywheel area...the mass of the DS is so close to the center that it is really negligible.

 

Carbon fiber does conduct electricity,I burnt up a perfectly good fairing charging the
battery on my ducati .

 

meentss02, Thanks for chiming in. I actually got the driveshaft because my stock one is about to go. It's a long story, but a parking brake cable became loose and had been resting on my aluminum ds. It had lathed it something fierce, and the ds is way out of balance and ready to go, That's why I needed a new ds, I went with the carbon for the vibration characteristics, not so much weight savings. So I'm glad to read your post. And z-ya, sorry to hear about that. I'm guessing I never ran into the conductive properties because all the panels I have ever made are for for more cosmetic than functional. I have always used a thick layer of epoxy resin to give that deep appearance. And that resin was not carrying current, even though the carbon would. Atleast I learned something new about carbon fiber today.

I would delete this post out of embarrassment, but I'll leave it here so others that didn't know can figure it out. Hopefully I can post in few days how good the new driveshaft is.

 

PST is a very well respected business, and they give great customer service. I believe they will be closed until next Thursday, as the owner invited their employees to his cottage over Labor Day weekend. Bob

 

Not a problem man...there are very few in this community that will ever have experience with this particular type of driveshaft simply due to the expense, but I've been nothing but happy with mine.

But as said, if you want to really feel a weight difference, switch over to an RPS clutch...holy cow. It saved 20 lbs over my old Ram Billet Steel fly/Powergrip setup, and feels like it gained a LOT.

 

^^^ great signature