TESTED: STEEDA Anti-Wheel Hop Package

by Billy Johnson


First iterations of new technologies are rarely flawless. When the Mustang ditched the solid axle in 2015 in favor of a 21st century Independent Rear Suspension, it transformed into a modern-day sports car with greatly improved ride quality and handling dynamics. Unfortunately, the new diff and subframe are mounted with soft, compliant rubber bushings that cause a significant wheel hop when launching the car and unwanted toe changes in corners. This affects drag and road racers alike. In order to eliminate these issues, we tested Steeda Autosport’s Ultimate ‘Stop the Hop’ Package and Adjustable Differential Bushing Insert System.

The S550 Mustang was introduced in 2015 and has a lot of soft rubber-mounted suspension components to reduce noise, vibration, and harshness (NVH) but is counter-productive for performance and handling. The differential is attached to the subframe with large, soft rubber bushings that have voids in the top and bottom. This causes the diff to have a significant amount of vertical movement even under moderate load. The subframe is then mounted to the chassis via more large, soft rubber bushings which cause the entire rear suspension to pivot and move under acceleration and cornering. This makes the chassis less responsive, consistent, and predictable. While our bone stock 2016 Mustang GT out-handled our 2009 Project E90 M3 in our Continental Tire ExtremeContact DW Tire Test, reducing this unwanted flex will further improve the Mustang’s already impressive capabilities.

We reached out to our friends at Steeda Autosports for their expertise on fixing this problem.  Steeda has been modifying Mustangs for nearly 30 years and is one of the world’s largest aftermarket parts manufacturers for Fords. They recommended their Ultimate IRS ‘Stop the Hop’ Package (p/n: 555-2129) which is available for all 2015-2017 Mustang GT, EcoBoost, or V6’s and is designed to reduce wheel hop, provide increased traction, and improve overall handling characteristics by stiffening the IRS subframe bushings.


Steeda boxOur Steeda ‘Stop the Hop Package’ came nicely boxed up and we were eager to get them on the car.
Steeda subframe isolatorsThe 'Stop the Hop' Package incorporates Steeda’s Bushing Support System which uses aluminum inserts to fill in the gaps of the rubber bushings. The bushing becomes fully encapsulated and movement is limited under heavy load. This effectively acts like a stiffer bushing but with minimal effect on NVH since the soft rubber is retained.
Steeda subframe alignment This package includes Steeda’s Subframe Alignment Kit which uses Delrin inserts to ensure the subframe is centered and aligned with the chassis. This is crucial for straight launches off the line and consistent handling right to left. In stock form, the inner diameter of the OEM bushing has half an inch of play which can allow the subframe, suspension components, and tires to be offset forward, aft, or side to side by as much as a quarter inch from center!
Steeda Vertical Link Integral linkAlso included in the kit are the Billet Aluminum Steeda Vertical Links (aka: Integral Link), which feature billet steel bushings that further reduce deflection over the factory rubber bushings in the stock links. 
Page 1 of 8 Next Page
Bookmark and Share
Tuesday, July 25, 2017 1:31 AM
I believe people see these types of mods as a waste, and they go for the more jee-whiz, techy or flashy stuff. But, if you actually want to drive something that feels like a race car, you really have to do mods like this.
Tuesday, July 25, 2017 8:22 AM
The spherical suspension bearing setup I have on Project S2000 is one of the best mods I've done to the car. Everything is nice and tight, the handling is more predictable, the chassis reactions to inputs is much closer to instantaneous.

I'm impressed with the ease of installation of this Steeda kit. I, like I'm sure many of our readers, have done the urethane bushing install jobs that require torches, presses, and sawzalls. I really dig the braces of the Steeda kit too.
Tuesday, July 25, 2017 2:24 PM
I remember swapping the clutch power spring on my 986 for a lighter one made the clutch 10 times better to operate!
Friday, July 28, 2017 4:08 AM
First thing I changed on my S550 was the clutch spring. It was bad on the S197 too. Makes a huge difference in clutch feel and if you find that too heavy you really need to hit the gym.
Friday, July 28, 2017 4:14 AM
I get the need for stiffer bushings, but those braces, really, how important are they once the bushings are done? This is a heavy car already and I'm not into adding more weight. If they lock the cradle solid that has to increase NVH and the probability something's going to break back there.
Monday, August 07, 2017 9:09 PM
Suspension bushings are definitely the first move for anyone wanting more feel in their car.

Will you also be doing the trans/engine mounts? I had great results stiffening them up in my E46.

Also, has Steeda studied how stiffening them up affects the sheet metal the suspension is bolted to? Having an E46 I'm sensitive to the common subframe tearing issues on the body.

Finally, I love how easy these reinforcements are to install. Makes it even easier than the DIY of injecting urethane sealant into the voids.
Tuesday, August 08, 2017 8:25 AM
@engineered - we are very familiar with the chassis issues with E36 & E46s. Thankfully the S197 & S550 Mustangs have fairly stout chassis' that have not had reported issues even with solid mounts in track and race cars over many years of abuse.

Because of this, we are extremely confident that the relatively mild (vs solid) Steeda bushing inserts will have virtually zero impact on the durability of the chassis.

We don't see the same urgency for engine and trans mounts in S197-S550 Mustangs that we have in E36-E46 BMWs (even M3s). The driveline does not seem to move as much in modern Mustangs and the increase in NVH would be higher than the reduction of engine/trans movement. By comparison, using a soft urethane engine or trans bushing in a E36-46 yields a big reduction in movement for a modest increase in NVH.
Tuesday, August 08, 2017 10:46 AM
@billyj, thanks for the response and that's good to hear about the Mustang's chassis and beefier eng/trans mounts.
Post Comment Login or register to post a comment.

MotoIQ Proudly Presents Our Partners:

© 2018 MotoIQ.com