Steeda’s Stop the Hop Street Starter Kit

Steeda's Stop The Hop Starter Suspension Kit


Steeda's Stop the Hop Street Starter Kit and Linear Drag Springs for the 2015-2024 Mustang GT


We brought our new 2024 Mustang GT to Steeda to get their Stop the Hop Street Starter kit and Linear Drag springs installed before we hit the track.




Like its S550 predecessor (and even the 03-04 SVT Cobra), the IRS system in the 2024 Mustang S650 is prone to wheel hop which in turn leads to broken axles and poor traction, two things any drag racer will never want.  While there are 100s of suspension options aimed at fixing this, for most people starting out, this Stop the Hop starter kit is a perfect option to begin with on your S550 or S650 Mustang. Paired with their Linear Drag lowering springs, this offers us an amazing lowered stance AND traction, which is a great combination.


Lethal Performance 2024 Mustang GT with Steeda Suspension

What is wheel hop?


Wheel hop is when the rear tires will basically "hop" up and down quickly under hard acceleration, for example launching at the drag strip. This is from the car basically rapidly gaining and losing acceleration as the suspension binds and releases. In an IRS car it is usually the entire rear subframe experiencing deflection, causing the rear end to experience a hard shudder. The 2015-up Mustang IRS comes from the factory with soft rubber bushings. While they are intended to provide excellent ride quality, super low NVH and great overall street manners, these soft bushings also welcome deflection with open arms and as a result: wheel hop.  We have broken axles on both our 2018 Mustang GT (which was bone stock) and our 2020 Shelby GT500 at the track due to wheel hop off the line.  Wheel hop is bad, mmkay?


How does the "Stop the Hop" kit help?


Steeda's "Stop the Hop" Street Starter Kit (SKU: SDA-555-4455) includes three essential components to help eliminate wheelhop:

Subframe Alignment Kit

Subframe Bushing Support System

IRS Subframe Support Braces


Steeda Stop The Hop Starter Kit Components


Let's go over each component and it's function, shall we?



Subframe Alignment Kit

From the factory, the bolt holes for the rear subframe bolts are rather large compared to the size of the bolts themselves (think hot dog in a hallway...). These large gaps result in your S550 or S650 rear subframe being out of alignment by up to 1/2 an inch. Steeda found the answer to these gaps by way of CNC-machined Delrin sleeves in their Steeda IRS Subframe Alignment Kit (SDA-555-4438). These dowels get inserted into your factory bolt holes and then your bolts will slide through them. The sleeves fill any gaps around the bolts and ensure a perfectly aligned installation every time, centering and squaring up your rear subframe to the chassis.


Steeda Subframe Alignment Kit


Product Benefits
Aligns subframe to chassis
No increase in NVH
Easy to install
No permanent modifications
Limited lifetime warranty
No additional hardware needed



Subframe Bushing Support System

Everyone needs a good support system and your subframe bushings are no exception. As mentioned earlier in the article, the factory bushings are made of soft, compliant rubber which gives way to deflection when under load. While you could certainly replace the bushings entirely with an aftermarket option, the process is not only labor intensive but can also lead to high NVH, more gear whine and more noises in general. Steeda's Subframe Bushing Support System (SDA-555-4437) basically envelops, aka supports, the factory bushings.  The bushing support system basically fills in the factory voids, eliminating any movement and, in turn, minimizing subframe deflection. These bushing inserts were the first of their kind on the market for the S550 and S650 and are made from CNC-machined, billet 6061 aluminum.


Steeda Subframe Bushing Support System Installed


Product Benefits
10 piece kit
Increases traction
No increase in NVH
Easy to install
No permanent modifications
Limited lifetime warranty



IRS Subframe Support Braces

The last piece of the puzzle in the Steeda Stop The Hop Starter Kit is their Steeda IRS Subframe Support Braces (SDA-555-5754). These braces are made in-house from 4130 chrome moly and finished with a silver powdercoat. These braces are STRONG and ultimately 'brace' together 3 important points on the rear of the Mustang, triangulating the subframe to the chassis. Steeda "utilized existing threaded holes in the rocker panel (the strongest part of the body) and connected that to the front mounting location of the IRS subframe and the rear mount of the lower control arm and toe link. Connecting these 3 points together not only adds rigidity that was lacking in the rear, but also more control of the whole car."  The subframe braces utilize all factory bolt locations so there is no need to drill or modify anything for installation AND does not add any NVH after install. 


Steeda IRS Subframe Braces


Product Benefits
Better handling for more stable cornering
Limits IRS subframe movement
No permanent modifications necessary
No added NVH
50% more connecting points
Reduces wheel hop
Limited lifetime warranty
Installation does not require removal of cradle



Steeda Linear Drag Springs

While still offering excellent street manners, Steeda's Linear Drag Springs (SKU: SDA-555-8231) were designed with the drag racer in mind. The rates on the springs were designed for the best weight transfer and most traction when launching a the drag strip. The Steeda Drag springs lower your S550 / S650 Mustang roughly 1" in the front and 0.75" in the rear while maintaining optimal rates of 150lb/in. in the front and 800lb/in. in the rear. 


Steeda Drag Linear Springs on 2024 Mustang GT - Before & After


Product Benefits:
Better weight transfer and traction on launch
Designed for competition racing but maintains outstanding street-able ride
Developed using advanced proprietary CAD data and exclusive 3D modeling
LIFETIME warranty



Huge thanks to Steeda for bringing us up to Georgia to get this awesome Stop The Hop suspension and Linear Drag Springs installed on our 2024 Mustang GT. Each piece of the Steeda Stop The Hop Street Starter kit is integral to minimizing movement in your S550 or S650 IRS rear subframe and getting you optimal performance for traction & handling. 


Lethal Performance 2024 Mustang GT and the Mustang King at Steeda


Need MORE traction? Steeda also offers a 'Stop the Hop' Street Enthusiast kit and a 'Stop the Hop' Drag Enthusiast kit that build on the Street Starter kit. 






Beyond these kits, they offer multiple other levels for Street, Handling and Drag racing applications. Here's a quick chart to show what is included in each package, so tha tyou can be sure to get the right Steeda Stop The Hop suspension kit for your S550 or S650 Mustang.


Steeda Stop The Hop Chart for the S550 and S650 Mustang





About the Author


Christy, better known as Cougs, has been part of #teamlethal since 2008. When she’s not with her better half, Alex, at a Drag & Drive racing event or posted up at a brewery, she’s enjoying a horror flick or crafting a new costume for the Mustang King.




Sources:  Everything To Know About The Stop The Hop Kits, Steeda ; Wheel Hop - Causes, Effects and Cures, SpeedNews; TESTED: Steeda Anti-Wheel Hop Package, MotoIQ