At Singh Autosport we manufacture custom pulleys for supercharged engines. We tuned this Range Rover for Mark Braham of Overfinch USA using our pulley and software. The gains on the Supercharged Range Rover are around 45-50hp, we also raised the RPM, removed the speed limiter/hesitations/flat spots, etc. When you drive the car, the supercharger kicks in earlier and you really feel the punch.
Overfinch is the market leader for aftermarket products for Range Rover. Overfinch USA and Singh Autosport will be working very closely for all future projects.
Please remember whenever you replace a factory pulley for a modified one, you have to programme the ECU.