This will increase your HP by as much as 20hp and by far is the best bang for the buck mod for your MINI. Installing this pulley will NOT cause a check engine light or any other failures as this is by far the most common mod any MINI owners do.
Way Motor Works 15% Supercharger Reduction Pulley R52 R53 2002-06 MINI Cooper S
Engine Cooling Fan Clutch-Base US Motor Works 22056
Us Motor Works Engine Cooling Fan Clutch P N 22162
Us Motor Works 22072 Thermal Fan Clutch
Us Motor Works Engine Cooling Fan Clutch P N 22611
Us Motor Works Engine Cooling Fan Clutch P N 21011