Steeda 'Stop The Hop' Handling Enthusiast Kit (Mustang 15-21)

Our Sales Experts take calls all the time from enthusiasts that want to eliminate wheel hop and improve handling while also staying on a tight budget. This is where the Stop the Hop Handling Enthusiast Kit comes in. Our team of engineers got together and came up with the best parts for eliminating unwanted wheel hop in the new S550 Mustang to help you have greater control when driving. 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. This is perfect for anyone that enjoys a responsive and tight handling sports car or anyone occasionally racing in autocross or road course. 

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.

Second is our tried and true IRS Subframe Bushing Support System. This 8 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.

The 3rd 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.

The 4th piece is Steeda's Adjustable Differential Bushing Insert System. These polyurethane bushings replace the soft rubber factory bushings that result in pinion changes, differential movement, and wheel hop. This will improve handling by helping to keep the rear of your S550 connected. You can expect some increase in NVH and may experience increased transfer of gear whine noise problematic to some Super 8.8 IRS differentials. 

NOTE: Steeda IRS Subframe support braces will not fit convertible. Due to changes in the OE subframe bushings, the bushing inserts will not fit 2021 GT500's or 2022 Mustang's.

Kit Includes:

• 555-5754 - Steeda IRS Subframe Support Braces
• 555-4443 - Steeda Adjustable Differential Bushing Insert System
• 555-4438 - Steeda IRS Subframe Alignment Kit
• 555-4437 - Steeda IRS Subframe Bushing Support System

Features & Benefits:

• May increase NVH
• Eliminate subframe movement
• Minimizes differential movement
• Simple install
• Squares subframe to the chassis
• No permanent modifications
• More predictable handling
• Greater control and stability