I really wouldn't bother Paul. I have looked into this and to be honest there are so many better ways of spending the money in terms of performance and/or weight reduction. I know of a tuner that has developed his on props that are much cheaper than the carbon ones and very similar in weight, so you get most of the benefits of weight reduction and reducing inertia through the drivetrain, but without the
I can`t see how carbon would be useful in a prop shaft as carbon has rubbish properties in Shear and all that load the prop shaft is under is sure to lead to failure. I could be talking rubbish.
If you want an honest un biased opinion about Carbon propshafts get in touch with Mark Shead at MA Developments. He has done extensive development work and is,contary to what others may say/quote the person responsible for the Carbon propshafts that are available for the Mitsubishi Evolution today.
I think you can contact or find contact details for him here
All very light, all very good, most guranteed upto 1000bhp and one of em over 1400bhp as i recall.
Sumo do CTG I think
Giken did one I think
And one of the manufacturers sponsor Keithj Coweies drag car which was around 1200bhp last I heard and gets caned sh1tless !!! so must be fairly strong.
the good thing about carbon is you can weave and bond it any way you like, hence it can be strong in whatever direction you want it to be.