2 liter Vittesse/GT6 Diff?

[monza6c]

Does anyone know just how strong a 2 litre Vittesse/GT6 diff is? will it take 150plus bhp? Will the Rotaflex couplings take it?
I talking about hill climb starts.

[Tnick]

Re: 2 liter Vittesse/GT6 Diff?

Len

I've read of several GT6 and Vitesses with a Triumph 2.5 PI (TR6) engine with no mention of changes to the diff. A tuning book I have for varous Triumphs claims the Vitesse/GT6 diff (when properly built ) is very strong, though it sugests that the 3.27 ratio is only suitable for the road.

With regard to the rotoflex couplings Canley Classics (http://www.canleyclassics.com/products.asp?article=cvkit1.xml) market a kit to replace the rotoflex couplings with a CV joint. They claim to have used in various motorsport events.

[b_caswell]

Re: 2 liter Vittesse/GT6 Diff?

Ratios range from high 4.875:1 down to low 3.27:1 but only the lower ratios were fitted to the stronger carrier that was used on 2ltr Vitesse and GT6 and Spitfire Mk iv and 1500. These can be identified by the fact that they use large drive flanges all round that take 3/8" UNF(9/16"AF)bolts.
But it is possible to have the high ratio gears built onto the stronger carrier. If your not using a limited slip diff the planet gears suffer and you may need a modified cross pin.(I believe Fortune engineering made these for trials cars)
Another point is that later cars rear suspension used a swing spring with only 4 studs on the diff mounting. If your using the rigid spring that goes with rotoflex drive shafts, you need to use the 6 stud diff casing to spread the mounting load of the spring.