he EVP POLARIS RZR XP Turbo Clutch Kit is designed and calibrated in conjunction with QSC and have arrived at a custom clutch weight and spring profile which provides great up shift and acceleration while maintaining back shift and belt life. We have calibrations available for just about every riding type and tire size. All clutch kits are designed to work with both the OEM and EVP Badass belts. Get the most out of your machine whether stock or tuned with an EVP/QSC RZR XP Turbo Clutch Kit!