I am getting a 3.9 from a Discovery and am planning to twin supercharge.
The chargers I have are TX15's (SC14's)
![Image](http://img641.imageshack.us/img641/9128/chargerspecs.png)
![Image](http://img43.imageshack.us/img43/8638/sc14map.png)
Does anyone have an idea of the gearing I should use on a 3.9? Would I be looking at an (engine) rev-limit of 5,500rpm? so would 2-1 be a good ratio? Would the boost level (dependant on cam profile and intercooler efficiency, I know) be acceptable? Also, I would be looking to change the camshaft. Does anyone have a good idea for a suitable profile for a setup like this? The chargers have electric clutches and a bypass system so will need to work with them turned off; but in saying that I imagine even a reasonably aggressive profile shouldn't have much trouble with moving a 1250kg (2750lb) car at low RPM when you have nearly 4 litres working for you.
I was thinking or a more aggressive profile to limit low end torque and push power up nearer the top (as a form of traction control). The Triumph is much lighter than the Discovery the motor has come from and I don't think the standard profile (for an auto box) will work too well when supercharged and put into a much lighter (and manual) car. I think I would have too much torque down low to be usable.
Cheers
Cam