Originally Posted by
Martin-Hadland
Thanks for the info Stevie, I can buy a shorter 5th so the R34 would probably the one to go for even though its rarer to get hold of. I'm thinking of making a pattern sump so that I can have one cast rather than welded up.
It will be turbo'd for sure (no point otherwise
) by whether its single or twin will have to decided when I see what sort of space I have, powerwise it needs t0 start with an 8 or more.
With boost and that engine....really, having a tall 5th gear will not be a problem.
From a simplicity point of view, I'd go for a big single. Manifolds dont need to be fancy, just functional, and all you'll need is a 2" or 2.25" max link pipe from one side to the other. A Single simplifies air filters and boost plumbing too.
With 255/40x17 and the 3.27 rear I seen 200mph at about 6700rpm. With a 3.55, I'd have needed about 7400rpm to achieve it ( 0.74 5th gear ), which with my engine would never happen.
So I'd say the 3.56 would be close to ideal, depending on your tyre sizes. But with lots of power and torque, shorter gearing is of little benefit.