scott863

Before I fell back to what I know and love best (Porsches), I was going to do a new Mustang with serious mods. One thing I found for Mustangs was a carbon fibre driveshaft. Has anyone made one of these for a 928? The weight reduction apparently helps with reducing driveline power losses.

hacker-pschorr

I've seen carbon driveshafts wadded up like a pretzel on high horsepower cars. Not sure I would trust a carbon torque tube.

ErnestSw

My impression is that carbon fiber is not strong in torsion.

FlyingDog

Do you mean the tube or the driveshaft in the tube? Driveshaft, makes sense to try. Tube, pointless waste of money.

Black Sea RD

The Mustang driveshaft is a conventional tube style drive shaft, while a 928 drive shaft is made of a steel rod approximately 1" in diameter. I really don't believe a carbon drive shaft for our cars would work all that well or hold up to the type of torsional movement as ErnestSw said.

A carbon fiber torque tube was a brief fantasy of mine to reduce the overall weight of my track car. However to have one made that would attach to the mounting points and hold the bearing units in place for the driveshaft would be very expensive and I was also worried about it's longevity since it connects the engine and trans together. There is some twisting of the engine that does happen under operation and breaking the mounting areas of the torque tube is a possibility. It would have to be engineered very well and the costs would be great.

Constantine

slate blue

The new aston martin DB9 has a carbon torque tube, i.e I believe the actual driveshaft is carbon, the driveshafts on F1 cars are carbon too.

Greg

hans14914

This subject was dicussed here on rennlist before, maybe 2 years ago. From memory, i think richard-blau928 was a part of the discussion. Its been a long time, but i think the general concensus was that it was a bad idea.
Hans

scott863

Thanks for everyone's opinion, if the Aston has it, should be pretty cheap to develop!

mark kibort

I also remember folks talking about the tubes winding up a full revolution. picture our torque tube shafts. dont think you could put 300ft-lbs on it and it would wind up more than a 20 degrees max.

mk

hacker-pschorr

You are being sarcastic here, correct?

jon928se

CF TT (Not the central drive shaft) should work pretty well at a rough guess around the same dimensions as the stock steel one. Unfortunately it would also require re-engineering the Bell housing and TC housing/front of 5sp box as it wouldn't be possible to get the forces out of the nice CF tube into just those four bolts - think say 10 bolts albeit smaller ones. Too much stress concentration around just those four fixings.