Roush Supercharger Upgrade Kit 727HP Phase 1 To Phase 2 Mustang 5.0L 2015-2017
Highlights
- Upgrades To Phase 2
- Cooler Heat Range Spark Plugs
- Certified To 727HP 610Lb-Ft
- Made In The USA
Roush Phase 1 to Phase 2 727HP Supercharger Upgrade Kit for all 2015, 2016 and 2017 5.0L Mustangs with a Roush Supercharger.
Are you looking for a safe and reliable way to upgrade the already installed Phase 1 Supercharger found on your 2015-2017 5.0L Mustang? If so, the team over at Roush Performance has the perfect solution for you and it’s available right here at CJ Pony Parts!
The Roush Phase 1 to Phase 2 Supercharger Upgrade Kit (P/N: 421994) builds on the outstanding performance and reliability of the Roush Phase 1 Supercharger Kit. Roush does this by adding proven core components and a careful calibration for quick and easy solution to achieve an additional 57 horsepower and 65 lb-ft of torque over the Phase 1 system. The end result is an amazing 727 hp/610 lb-ft of torque while preserving the day-to-day confidence and driveability you expect from the team at Roush Performance.
Features and Benefits:
- 727 hp @ 6,850rpm and 610 lb-ft @ 5,100rpm
- Additional 57 Horsepower and 65 lb-ft of Torque Over Phase 1
- Safely and Reliably Increases Fuel Pump Output
- Does NOT Require Opening of the Fuel System
- Cooler Heat Range Spark Plugs Help Ensure Complete Combustion
- Prevents Detonation Under the Higher Boost Levels
- Smaller Diameter 80mm Pulley Increases Boost
- Does NOT Require a Belt Replacement
- Phase 2 calibration Delivered Through Roush Diagnostic Tool (RDT)
Included in Kit:
- Digital Fuel Pump Controller
- 80mm Supercharger Pulley
- (8) Motorcraft Spark Plugs
- Roush Diagnostic Tool (RDT) Re-Flash Voucher
Applications:
- 2015-2017 5.0L Mustangs with Roush Supercharger System (P/N: 421283) - Manual or Automatic
- 2015-2017 Roush RS3 Phase 1 Supercharged Mustangs
*50-State emissions-legal (CARB E.O. #D-418-29).
Please Note: This kit will physically fit any 2015-2017 5.0L Mustang, but RHD (Right-Hand Drive) vehicles but the included Roush Calibration will NOT work on any 2015-2017 5.0L Mustang outside of the US and Canada, so those vehicles will require custom tuning which is NOT Included). Custom tuning can be purchased through our program with Lund Racing and the nGauge Tuner, see P/N: NG4-V.
ATTENTION: Updated Operating System Requirements for the Roush Diagnostic Tool (RDT). The Technical Service Bulletin TSB 21-0802-AA has been issued by Roush. As of September 10, 2021, Windows 10 will be the ONLY operating system that will be supported by Roush Performance for the Roush Diagnostic Tool (RDT). Older operating systems, such as Windows 7 or earlier Windows operating systems (XP, Vista, etc.), will not be supported. All instances of RDT will need to be updated to the most current release. All previous versions of RDT will NOT be able to program or configure modules due to a software license time-out.
The updated minimum recommended PC Hardware Configuration will be:
- Processor minimum: 2.4 gigahertz (GHz) or greater Intel I5/I7 Dual Core
- Memory minimum: 4 gigabyte (GB) RAM or greater
- Windows 10
- Microsoft .NET Framework 4.0 or later
California Residents: Proposition 65 Warning
Related Categories: Mustang Parts, Mustang Engine, Mustang Supercharger Kits, Mustang 5.0L Supercharger Kits
This item is 50-state legal (CARB E.O. Number D-418-29)
Installation Difficulty

Intermediate skill is required for this installation.








