Steeda Autosports

Steeda Mustang GT350/Mach 1 Handling Ultimate Kit (2015-2023)

 555 2129 G
( saved $100.00 )
Not In Stock
Typically ships in 2-3 weeks.

Our Sales Experts take calls all the time from enthusiasts that want to eliminate wheel hop and improve the handling of their GT350 or Mach 1. This is where the Handling Ultimate Kit comes in. Our team of engineers got together and came up with the best parts for eliminating unwanted wheel hop and bushing deflection in the new S550 Mustang to help you take corners faster and get tack sharp handling. A kit that gives you the fundamental foundation for ultimate traction and suspension compliance. As we have explained before, the factory IRS subframe, (often inaccurately referred to as a cradle), mounts to the S550 chassis with 4 mounting locations utilizing 4 soft rubber bushings with plenty of voids, even in the bolt holes. The kit we put together addresses these issues and more.

First is our Alignment dowel kit. This fills the factory bolt hole voids with CNC machined delrin inserts that will square up the rear subframe to the chassis. By filling these voids we are also limiting the side to side and front to back movement of the subframe that is present under hard acceleration and braking.

The 2nd component of this kit is the strongest support brace for the S550 IRS on the market!! Made in-house from chrome-moly steel, this brace is designed to support the factory subframe by directly tying it into the chassis at key mounting locations. Using factory mounting locations on the factory frame, this 5 point brace supports the front factory mount and the lower control arm mount as well. A simple bolt-in design, this brace ties the subframe to the chassis in the best possible way.

Steeda's Rear Toe Links are the 3rd item in the kit. They help you improve your launch and allows you to control the toe of your Mustang during launches. Improve your 60-foot times and get down track faster with this upgrade from Steeda.

4th in the kit, the Steeda Billet Vertical Links with Urethane Bushings reduce deflection and tighten the rear of your S550. This CNC machined 6061 billet aluminum piece is a great step up over the stamped factory piece. Reducing bushing deflection will help you put more power to the ground and improve control, while also preventing unwanted movement and wheel hop. Bushing deflection from the stock rubber bushings can cause sloppy or soft handling and will hold your Ford back from reaching its full potential.

Lastly is our tried and true GT350/Mach 1 IRS Subframe Bushing Support System. This 6 piece kit was a first of its kind in the performance aftermarket and so innovative and popular we patented its design! Made in-house from billet 6061 aluminum and featuring stainless steel hardware, this kit fills all the factory voids in the IRS subframe mounting locations. Its job is to prevent up and down movements of the subframe.

NOTE: Steeda IRS Subframe support braces will not fit convertible

Kit Includes:

  • 555-5754 - Steeda IRS Subframe Support Braces
  • 555-4449 - Steeda GT350/Mach 1 Subframe Bushing Support System
  • 555-4438 - Steeda IRS Subframe Alignment Kit
  • 555-4129 - Steeda Billet Aluminum Vertical Links with Urethane Bushings
  • 555-4120 - Steeda Adjustable Rear Toe Links

Product Benefits:

  • Eliminate wheel hop with little to no increase in NVH
  • Eliminate subframe movement
  • Simple install
  • Squares subframe to the chassis
  • No permanent modifications
  • More predictable handling
  • Greater control and stability

warningWARNING: California Residents: Cancer and Reproductive Harm;

Installation Difficulty:
Tech Recommended
Tools Required:
Basic Shop Tools
Estimated Install Time:
(approx.) 6 Hours
Vehicle Fitment:
2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023
Vehicle Trim:
Mach 1
Vehicle Trim:
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