Roush Supercharger Upgrade Kit 727HP Phase 1 To Phase 2 5.0L 2015-2017

100% of 100


  • Upgrades To Phase 2
  • Cooler Heat Range Spark Plugs
  • Certified To 727HP 610Lb-Ft
  • Made In The USA
MSRP $1,248.00
You save $48.01

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

- 2015-2017 5.0L Mustangs with Roush Supercharger System (P/N: 421283) - Manual or Automatic
- 2015-2017 Roush RS3 Phase 1 Supercharged Mustangs

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

Manufacturer Part Number: 421994

*50-State emissions-legal (CARB E.O. #D-418-29).

Roush engineers spend hundreds of hours in the laboratory, on the dyno and out in the field to ensure their components and calibrations deliver consistent performance in all conditions. And this upgrade kit is a perfect example of that research and development. Installing easily with a preset plug and play fuel pump controller, colder heat range spark plugs, and a higher boost 80 mm supercharger pulley. With the Phase 2 Calibration you will notice the increased horsepower and torque in your supercharged S550 in a matter of minutes.

Order the Roush Phase 1 to Phase 2 727HP Supercharger Upgrade Kit for your 2015-2017 5.0L Mustangs with a Roush Supercharger from CJ Pony Parts today!

California Residents: Proposition 65 Warning

This item is 50-state legal (CARB E.O. Number D-418-29)

Installation Difficulty


Intermediate skill is required for this installation.

Vehicle Fitment

This product will fit the following Mustang years:

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