The ROUSH Phase 2 supercharger upgrade kit builds on the outstanding performance of our 2015-2017 F150 Phase 1 supercharger system by adding proven core components and careful calibration. This kit adds an additional 50 horsepower and 28 lb-ft of torque when used with our 600 hp/ 557 lb-ft Phase 1 supercharger system (PN 421983). The result is an outstanding 650 hp / 557 lb-ft of torque while retaining the daily confidence you expect from the engineering of ROUSH Performance.ROUSH engineers spend hundreds of hours in the laboratory, on the dyno, and out in the field to ensure the components and calibration deliver consistent performance in all conditions.The upgrade installs easily with a higher boost 75 mm supercharger pulley and a ROUSH Diagnostic Tool (RDT) Phase 2 reflash voucher. The upgraded Phase 2 calibration can be downloaded to your ECU in minutes by your dealer.