Steeda GT350/Mach 1 Handling Ultimate Kit (555-2129-G) - 2015-2023 Mustang GT350 & Mach 1
Take the handling and traction of your Shelby GT350 or Mustang Mach 1 to the next level with the Steeda Handling Ultimate Kit. Specifically engineered for 2015-2023 GT350 and Mach 1 models, this comprehensive IRS suspension package addresses the factory independent rear suspension's biggest weaknesses by reducing wheel hop, minimizing bushing deflection, and dramatically improving chassis stability. Whether you're carving corners, launching hard at the drag strip, or attacking your favorite road course, this kit provides the foundation for a more predictable and confidence-inspiring Mustang.
By combining Steeda's proven IRS suspension components into one complete package, the Handling Ultimate Kit strengthens the rear subframe, improves suspension geometry, reduces unwanted movement, and delivers sharper handling without permanent modifications. The result is improved traction, increased suspension compliance, and more consistent performance while maintaining excellent street manners with little to no increase in NVH.
Kit Includes
- Steeda IRS Subframe Support Braces (555-5754)
- Steeda GT350/Mach 1 IRS Subframe Bushing Support System (555-4449)
- Steeda IRS Subframe Alignment Kit (555-4438)
- Steeda Billet Aluminum Vertical Links with Urethane Bushings (555-4129)
- Steeda Adjustable Rear Toe Links (555-4120)
Features
- Designed specifically for GT350 and Mach 1 IRS suspension geometry
- Reduces wheel hop with minimal increase in NVH
- Eliminates unwanted IRS subframe movement
- Aligns the rear subframe to the chassis using precision Delrin dowels
- Strengthens the IRS with heavy-duty chromoly support braces
- Billet aluminum vertical links with urethane bushings reduce suspension deflection
- Adjustable rear toe links allow precise suspension tuning
- No permanent modifications required
- Simple bolt-on installation
- Manufactured from premium billet aluminum and chromoly steel components
Benefits
- Improves traction during acceleration
- Reduces wheel hop and bushing deflection
- Provides sharper, more predictable handling
- Increases rear suspension stability under cornering and braking
- Improves launch consistency and 60-foot performance
- Enhances driver confidence on the street and track
- Maintains excellent ride quality with minimal added NVH
Fitment Notes
- Fits 2015-2020 Shelby GT350 and GT350R.
- Fits 2021-2023 Mustang Mach 1.
- IRS Subframe Support Braces do not fit Mustang Convertible models.
- Direct bolt-on installation with no permanent modifications required.
Fitment
- 2015 Ford Shelby GT350
- 2016 Ford Shelby GT350
- 2017 Ford Shelby GT350
- 2018 Ford Shelby GT350
- 2019 Ford Shelby GT350
- 2020 Ford Shelby GT350
- 2021 Ford Mustang Mach 1
- 2022 Ford Mustang Mach 1
- 2023 Ford Mustang Mach 1
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