An SD1..

[sidecar]

An SD1 will be more aerodynamic than a Cob replica even if the SD1 is not all that slippery, I have a Sumo Cob replica with a 300 BHP 4.6 in it, I then run a 100 NOS shot on top but I doubt that it would top 160mph even if it was geared to do this. In fact it is geared for 155 at 6000 RPM which is at the rev limit. (I spent along time with a gear calulator whilst googling varrious gearboxes and diff ratios, in the end I used a set of close ratio Quaife gears in a T5 box and a 3.36:1 diff, I run 17" wheels but the profile escapes me at the mo)

Its not the frontal area that it the problem in a Cob, it is the MASSIVE turbulence behind the windscreen which causes all the drag. If you hold something up whilst travelling a speed and let it go, it does not fly out of the back of the car, it flies forward and smacks the back of the windscreen!

Personally I think that the figures in the first post just don't add up at all!

250 BHP out of a NA 3.5 is a good figure, you would be hard pushed to get much more without the engine being a real pig and needing a rebuild every 1000 miles.


Doh...you have a GT40, not a Cobra rep...I'll get my hat!

[DaveEFI]

A - right. Forgot about the non standard diff. Or rather I assume it is non standard - don't have any details for the NAS SD1. It wouldn't be easy to fit much larger rolling radius tyres, especially with lowered suspension.