Adjustable Black Tensioner Stop by ALTA Performance. Replace your broken or worn out stock belt tensioner dampener on your Supercharged MINI! The ALTA Performance Tension Damper is a very simple device that will outlive the life of the car! The OEM dampener is very well known to cause lots of problems on your MINI. The bushings wear out causing strange noises and dampener failure. When the dampener wears out, it causes instability in your your belt tension, premature belt failure, shortened life of bushings and tensioner spring, and slippage under full throttle. Also, the OEM dampener can't protect your crank pulley and related parts from getting destroyed in the event a belt fails.