This tuning torque spring from Polini increases the pressure over the original spring by 8%. The torque spring has the task of pressing the pulley in the rear converter to the belt. It also exerts pressure to allow the variator to shift. A stronger spring is required once engines have been tuned otherwise the belt slips or the engine doesn`t rev well. The torque spring is always in close contact with the variator. If another spring is mounted, the Vario must be adapted to each upgrade. Spring loading Original: 37 / 39mm / kg spring loading Polini: 37 / 42mm / kg wire thickness: 5 mm Overall length: 95mm inner diameter: 54.2mm number of turns: 6