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2015-2017 Mustang Phase 1 to Phase 2 Supercharger Upgrade Kit 727 HP

Product Features

  • 727 hp @ 6,850rpm and 610 lb-ft @ 5,100rpm
  • Preset plug and play digital fuel pump controller safely and reliably increases fuel pump output without opening fuel system
  • Cooler heat range NGK spark plugs help ensure complete combustion without detonation under the higher boost levels of Phase 2
  • Smaller diameter 80 mm pulley increases boost, installs in minutes, requiring no belt replacement
  • ROUSH/Ford Racing Phase 2 calibration file delivered with exclusive ROUSH Diagnostic Tool (RDT)
  • Includes 3-year/36,000-mile ROUSH Parts only limited warranty
  • Voids optional Roush limited Powertrain/Drivetrain warranties
  • Not approved for sale or installation in the state of California or any other states that require an EO number.
  • Part#: 421994

The ROUSH Phase 2 supercharger upgrade kit builds on the outstanding performance of our 2015-2017 Phase 1 supercharger system by adding proven core components and careful calibration, for an additional 57 horsepower and 65 lb-ft of torque over our 670 hp/ 545 lb-ft system (PN 421823).

The result is an outstanding 727 hp / 610 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 preset plug and play fuel pump controller, colder heat range spark plugs, and a higher boost 80 mm supercharger pulley. A ROUSH Diagnostic Tool (RDT) reflash voucher is in the box, and your upgraded Phase 2 calibration can be downloaded to your ECU in minutes by your dealer.

Included in the Kit:

  • Fuel pump controller
  • 80mm Supercharger Pulley
  • (8) NGK Spark Plugs
  • RDT Reflash Voucher


Not approved for sale or installation in the state of California or any other states that require an EO number.

This kit comes with an extended parts warranty (ROUSH Supplied Parts Only), which is good for 3 years or 36,000 miles from the date of retail purchase. Please note that if this system is installed on a 2015-2017 ROUSH Stage 3 Mustang, the vehicle's powertrain warranty will be voided.



  • Difficulty: Intermediate
  • Time: 3 hours
  • Required Tools: Basic tools
  • Download instruction manual