ALFAGTV6.COM

Z, I hadn't asked Beninca about building a driveshaft...
I'm happy to give them a call and see what they say.

The bonus of that, Is the whole assembly will leave balanced to their (exacting) standard and ready to go.

CF would be v nice, Pieter- we just need to wait for some guys to start writing them off so we can get some parts for cheap!!!!

While sniffing around the net I found that the GTR does infact have a dampened tailshaft, with damping being provided by what looks a lot like a sprung centre that would be used in a clutch.

Something I've been thinking about for a while based on some of the things that have been posted on various forums by guys like MD, but also Richard Jemmison over on AlfaBB.
MD says that 1 rubber coupling at the engine is a minimum. Richard says that 2 couplings are required if you use a solid centre clutch.
But Kevins bonded rubber 2 piece design pointed me to another method of thinking.

How about a fiberglass tailshaft???

Bare with me here. Fiberglass gets used to make all sorts of springy yet strong components, including the leaf springs in some model Corvettes.
I was watching s series of Youtube videos (LWIFOTI ) by an Aussie bloke and he did 1 video that I thought was particularly interesting: https://www.youtube.com/watch?v=KHXVf0SaJpA
The nuts and bolts of it are that fiberglass is, depending on the grade of 'glass, nearly as strong or stronger than carbon fiber. But fiberglass isn't as stiff as CF (it will flex more for the sam applied load).

So the idea behind the mad scientist thinking goes along the lines of this:
Rubber coupling at the engine. I want to use a more modern type of coupling rather than the Alfa 1. Probably 1 from a V8 Holden Commodore with an MD type adapter.
A single piece fiberglass tailshaft.
A CV joint at the clutch input shaft.
And a solid centre clutch disc.

Duk , the 155 DTM cars used a flex composite disc as a coupling . Also update , my mates GTV3.7 has done nearly a season of racing with TRT tube prop with cvs on standard set up transaxle with MD styled reinforced clutch housing ... And my old gtv6 race car is into its 5th season with standard prop and coupling cage upfront . So maybe no need for all the other type couplings .