Steeda Mustang 'Stop the Hop' Street Ultimate Kit (2015-2022)

16 Review(s)
$52.00 (5%)
Give your 2015+ Mustang the proven performance of Steeda manufactured suspension parts. This Steeda Mustang Ultimate IRS 'Stop the Hop' Package for your 2015+ Mustang GT, EcoBoost, or V6 is designed to provide increased traction, stiffen the IRS subframe, and reduce wheel hop.

Part Number: 555 2129

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Give your 2015+ Mustang the proven performance of Steeda manufactured suspension parts. This Steeda Mustang Ultimate IRS 'Stop the Hop' Package for your 2015+ Mustang GT, EcoBoost, or V6 is designed to provide increased traction, stiffen the IRS subframe, reduce wheel hop, and improve overall handling characteristics.

Which "Stop the Hop" Kit is for you?

Reduces wheel hop Our IRS 'Stop the Hop' Package addresses wheel hop issues notorious with the new 2015 Mustang. The Steeda IRS Subframe Bushing Support System helps with rear subframe deflection which is a direct cause of wheel hop. These bushing supports stiffen the rear subframe allowing the car to increase traction to the rear wheels. In conjunction with the bushing we also include our IRS Subframe Alignment Kit, which ensures your subframe is directly aligned to your chassis, and results in straight launches off the line.

No added NVH Our Steeda Vertical Links are far superior to the stock vertical links on your S550 Mustang. They feature billet steel bushing sleeves and spacers, providing less deflection than the rubber bushings in the stock links, without increasing NVH. The strength of the billet that the Steeda Vertical Links are made of will provide a more solid feel to your suspension and will not flex under load.

Limits IRS sub frame movement Our Steeda Mustang IRS Subframe Support Braces tie this Steeda Stage 3 Handling package together. These quality 4120 chrome moly steel braces are engineered to connect 3 very important points on the S550 chassis. The result of this solid connection is added rigidity that lacks in the rear of the 2015+ Mustang. By stiffening the connections of the rear of the chassis, this one component is able to limit IRS subframe movement, reduce wheel hop, and improve handling during cornering.

Improves vehicle handling Our Steeda Adjustable Rear Toe Links improve the handling characteristics and improve your vehicle's overall handling response. These toe links have a large range of adjustability and adjustments can be made while they're installed on the car.

Package Includes
  • 555-4437 - 2015 Steeda Mustang IRS Subframe Bushing Support System
  • 555-4438 - 2015 Steeda Mustang IRS Subframe Alignment Kit
  • 555-4121 - 2015 Steeda Mustang Billet Aluminum Vertical Links
  • 555-5754 - 2015+ Steeda Mustang IRS Subframe Support Braces
  • 555-4120 - 2015+ Steeda Mustang Adjustable Rear Toe Links
Product Benefits
  • Improves vehicle handling
  • On-car toe adjustability
  • Improves suspension compliance
  • Increases traction
  • Aligns subframe to chassis
  • Limits IRS sub frame movement
  • Reduces wheel hop
  • No added NVH

NOTE: Steeda IRS Subframe Support Braces Will Not Fit Convertible

Add the Steeda S550 Mustang Rear Lower Control Arm Spherical Bearings to further control toe and reduce deflection under hard launches!

Purchase your Steeda Mustang Ultimate IRS 'Stop the Hop' Package for your 2015+ Mustang GT, EcoBoost, or V6 at Steeda Autosports today!

See this kit in action on our Steeda Q500!

Notice how composed our Q500 is throughout this turn at Palm Beach International Raceway.

Steeda S550 Stop The Hop InfographicFind out which Stop The Hop Kit is best for you!


CA Residents: Cancer and Reproductive Harm WARNING

Hey guys this is John from Steeda. I want to get guys a little more info today on our Stop the Hop Kits. We've got three available now including our new Stop the Hop Enthusiast package. Let me go through them all individually. We're gonna start with our Stop the Hop Starter Kit. Now this kit includes our Steeda Subframe Braces which are these right here. They help eliminate lateral movement in the subframe itself and they link it to the chassis more effectively. We've also got our Steeda Subframe Alignment Kit. Now these dowels right here they fill the voids between the stock bolts and subframe. As they're a little bit different size they can have up to a quarter inch of movement in most cases in any direction. This helps keep the rear end centered every time under the car and to close out the starter kit we've got the Subframe Bushing Support System. What these do is they fill the voids in stock bushings and that helps to control the deflection and the oscillation of the bushings under a hard launch. It leads to more consistency and less wheel hop. Now if you want to turn the starter kit into an enthusiast kit, move in and move towards our Steeda Lower Control Arm Spherical Bushings. We found that up two degrees of movement is found in the bushing under a hard launch and this doesn't allow that. It so it's going to lead again to more consistent launches and less wheel hop and we found our Steeda Stop the Hop Ultimate Kit. What this is is it builds on the starter kit and includes our new Steeda Toe Links and these help control the tow on the car. They're a lot stronger than a factory pieces. They don't have as much movement or flex to them and we got our CNC machine Steeda Vertical Links. These are one piece CNC design with a very large bushing in them. We offer it with urethane or delrin. Depending on how stiff you want them and what that means is, it helps to stop binding which we found in a stock intercoaling which is what Ford calls it and not binding actually creates an artificial spring rate which changes as the increased movement on the rear axles and that leads to a lot of wheel hop issues and inconsistence. These are going to eliminate that problem and if you want to add it the spherical bushings to this kit you've gotta drop-down on our web site. Just let our performance experts know. You can also add our Steeda differential bushing insert system to any of these kits and you really get the ultimate control over the rear end on your drag car. Now if you've got any questions about your project, need some tech advise we go by the motto of Speed Matters. It matters to us, it matters to you. We want to help you guys get on the track have fun turn some great results. It's what we've been doing for 30 years. Give our performance experts a call. We'll be more than happy to help you out. Thanks for watching I'll see you guys soon. Steeda S550 Mustang 'Stop the Hop' Starter Kit (2015-2019) Part Number: 555 4455 Steeda S550 Mustang 'Stop the Hop' Enthusiast Kit (2015-2019) Part Number: 555 4456 Steeda Mustang Ultimate IRS 'Stop the Hop' Package All (2015-2019) Part Number: 555 2129
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Fitment & Features


Manufacturer: Steeda Autosports
Made in USA: Yes

Installation Information:

Level of Difficulty: Difficult
Install Time: About 4 1/2 Hours
Tools Required: Basic Shop Tools

Vehicle Fitment:

Fits Model Year: 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022

Customer Reviews

Rating Snapshot

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Average Customer Ratings


All Hop Completely Gone
Works as promised. Put on performance half-shafts as well.
Did you find this helpful?  2 of 2 Found Helpful
I ordered this kit and the rear lower control arm spherical bearings. This has been the most significant mod for my mustang to date. I have had 0 wheel hop and with the spherical bearings I can launch hard and keep the car straight. I have several engine and performance mods and my car feels safe and secure now. The whole car feel straight and tight!
Did you find this helpful?  5 of 5 Found Helpful
Installed the entire stop the hop kit plus the differential bushing spacer kit on my 2019 Mustang GT. The kit works - no more wheel hop. Kit installed in stages so I can tell you that each piece helped but wheel hop not completely resolved until entire kit installed.
Did you find this helpful?  7 of 7 Found Helpful
I recommend this for any mustang that it'll fit. Words don't describe how good the difference from stock is. If you got the money for it, buy it. If you don't, then save for it.
Did you find this helpful?  8 of 8 Found Helpful
Verified Buyer  
Big change
The kit didn't completely stop the wheel hop specially when the tires are cold . I live in the indiana so hopefully it'll make a huge difference in the summertime . Wintertime It still wheel hops. Definitely stiffened everything up and made it a more solid ride . Shocks are next .
Did you find this helpful?  21 of 23 Found Helpful
Verified Buyer  
Almost stopped the hop.
Stock gave me terrible wheel hop even with the pp package on my car, I started adding these parts one at a time, each one has tremendously helped with my wheel hop. This package cured about 80% of my hop, worth the money if you asked me. Hop is tolerable at this time, but when I added my lower control arm spherical bushings the car was transformed, the car was planted to ground and drives beautiful now I also added the differential bushings as welll. My car is a blast to drive now, added the Whipple Supercharger and with these suspension upgrades the car was horrible with the wheel hop.
Did you find this helpful?  30 of 33 Found Helpful
I now have ZERO wheel hop!
I forgot to update this after installing the Steeda springs and wheel hop kit, I've had them on for a couple weeks now. I'm loving the look with the springs, and there is definitely a noticeable difference in handling. Ride quality suffers a little, but it's not terrible. The wheel hop kit (IRS subframe bushing support system) does exactly what it's advertised to do, I now have ZERO wheel hop!
Did you find this helpful?  21 of 22 Found Helpful
All in all I am very impress and would highly recommend this product to any mustang owner
I have been unhappy with my suspension on my 2015 Gt pp since adding additional Hp with my Tvs supercharger and my wife was not filling warm and fuzzy when riding in my car any more.She was complaining about the back end not feeling stable and to much body roll.So I did lots of research over last two months and decided to go with steeda product. Stop the hop wheel package Front and rear steeda sway bars Billet sway bar mounts Differential bushing (Black) I all ready installed ford 1in drop racing spring but would like to upgrade to some steeda spring,Shocks,struts when they all become available.So after having my local performance shop install everything 8 hours install and driving it for a few days around town,freeway and through some good turns.Me and my wife are so impressed the back end is solid planted to the ground. It just feels so much more stable and body roll wheel hop and car squat is gone.I have not notice any additional NVH and that was a concern being I have a one piece aluminum driveshaft.All in all I am very impress and would highly recommend this product to any mustang owner.I work with Chad he was very helpful on getting me all dialed in.
Did you find this helpful?  15 of 15 Found Helpful
Was well worth the investment
Mine feels very planted, no hop or stepping out when I give it the beans to pass (or just be a road hooligan - LOL). Was well worth the investment IMO.
Did you find this helpful?  9 of 9 Found Helpful
time to give props to Steeda
My car would not hook up at all. Basically if you gunned it in 1-3 you were burning rubber. The two kits I ordered were Stop the Hop and Differential Bushing Insert System. I opted for the metal bushing. I was worried about too much noise but it seems fine to me. Basically if you have loud exhaust I do know if you can even tell the difference. If anything the car sounds more connected to the transmission if that makes sense. It hooks up at least 70% better now and that's conservative. For those that are wondering about alignment, I had the car aligned at it's zeroed out perfect. Anyway it will still burn tires but it is night and day trying to manage. With this I do not have the feeling the car is going to do a 180 at any given time.
Did you find this helpful?  10 of 10 Found Helpful
Launch the car and you can notice a difference in deflection
Steeda IRS bushing inserts: Install is very easy and you don't notice any difference in ride comfort or noise. However, while I did these the same time as Eibach Sportlines, they stand out on their own. Launch the car and you can notice a difference in deflection. IRS subframe connectors: Obviously no noticeable NVH changes, but the car does feel better when you gas it hard out of a corner. I'm looking forward to testing this beefed rear at the track soon.
Did you find this helpful?  10 of 11 Found Helpful
Thanks Steeda
Steeda IRS braces installed. Very easy install, took about 30 mins (mostly because I had to put the car down and move adjust the lift since it was still kind of in the way). Combined with the diff bushing inserts and the subframe inserts, the car is a completely different vehicle. Super happy!
Did you find this helpful?  3 of 3 Found Helpful
wheel hop on my car is 100% eliminated
A couple of months ago, I started looking into overhauling the suspension of my 2015 GT PP. Up to that point, I had put about 7000 miles on my Mustang which allowed me to get a good sense of the issues with the IRS and overall suspension in stock form. Specifically, I wanted to stiffen up the entire rear end and eliminate the dreaded wheel hop while keeping NVH as close to the stock levels as possible. I also decided to replace the stock PP springs and sway bars in order to improve the overall handing, reduce body roll/brake dive and get rid of the bouncy ride. After going through a ton of feedback on the various solutions from the aftermarket (a lot of which came from fellow mustang6g members), I decided to go with Steeda. Below are the parts I chose to go with. Differential Bushings (Red/Street) Subframe Alignment Kit Subframe Bushing Support Vertical Links Rear Toe Link Subframe Suport Braces Linear Sport Springs Front and Rear Sway Bars and Billet Sway Bar Mounts Bumpsteer Kit I already had the Extreme G-Trak Brace installed. Now to the most important part...the results. The handling of the car is on a whole different level after the suspension upgrades. Minimal pitch and roll during braking, turns and transitions. Overall, the entire car is very tight with much better turn in. As expected, the biggest improvement is the rear end. The power delivery through the IRS is fantastic. The wheel hop on my car is 100% eliminated. The rear tires feel as if they are glued to the ground. Coming out of corners, I am able to get on the throttle earlier and more aggressively without any drama. In terms of NVH, I hear some gear whine in 6th gear under minimal throttle between 75 and 80mph (windows closed/stereo off) as a result of the differential bushing inserts. Apart from that, I can't tell a difference compared to stock. Even the ride quality feels great. My fiance couldn't tell that anything had been done to the car. Overall, I am very happy with the results. Props to Steeda for the excellent work they have done. In the near future, I am looking forward to adding a quality set of performance shocks/struts and hitting the road course.
Did you find this helpful?  12 of 12 Found Helpful
The handling of the car is just perfect
I am beyond please with everything that Jamie did for the installation and alignment. David was an absolute pleasure to deal with in buying and setting up the appointment for me. Everyone at Steeda has been a joy. The car has been completely transformed. The ride quality with the progressive springs is 3 times better vs. the stock GTPP springs. The handling of the car is just perfect. It is so, so flat now when pushing the car hard in any type of turn. Brake dive has been greatly reduced. I would say by 80-90%. I can mash the brake pedal and it just stops, so tried and true. The front-end barely dives at all. This is from 70-75mph and just mashing the pedal. It truly begs for more speed when entering turns. Of course, this only on roads and not a race track or autoX course. Wheel hop has been greatly reduced. I still have a couple more parts to order to virtually eliminate it all together and those will be ordered at a later date. Shifting hard to 2nd gear, I just now get wheel spin and no hop. Only time I get a little hop is via a hard launch. But again, it is greatly reduced and doesn't happen all the time. The car is so quiet, no increase in NVH in anyway. This has been some of the best money I have ever spent on any car mods, PERIOD. Their parts deliver what they promise and produce outstanding results. Anyone on the fence, I highly recommend you go ahead and purchase their stuff.
Did you find this helpful?  3 of 3 Found Helpful
Steeda got it right
I had my progressive springs and well, many other suspension goodies installed last Friday in Valdosta and I can tell the car rides like it is on rails now. Even with the rough roads here in South Carolina I haven't come close to bottoming out or needing the bump stops. Again all I can say is Steeda got it right.
Did you find this helpful?  2 of 2 Found Helpful
I'm officially a believer!
Ok. So I know everyone has already made threads about their Steeda stuff, but I'm officially a believer! Springs Sway bars Sway bar Billet Brackets Vertical Links Toe Arms Bump steer kit G-Track Brace IRS bushings MMR Camber Plates Performance wheel alignment The car is a go kart. Set the front sway bars to the center and rear to the lower settings, entry high speed turn is predictible, so much so I haven't learned the limits yet. The ass can be easily manuvered with throttle (Race mode/traction off). The body roll seems like it's gone (once the track wheels/tires come in I'll know for sure), it's unreal, I am in LOVE with the car now. This is the way it should've come from the factory for the PP cars. Really a learning curve, since now everything is souch more compossed. The IRS bushings and arms drastically changed the feel of the car on take off, the power actually goes to the tires (which I spin even easier now, even with camber still within factory specs.) There's not that feeling like the IRS wasn't properly fastened, it feels like it's built in to the body. Such a great mod. I'm ordering the IRS brackets as well, but I don't see how it can really improve further. It that good!! Steeda has my vote!
Did you find this helpful?  3 of 3 Found Helpful
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