Steeda S550 Mustang Rear IRS Subframe Support Braces (2015-2019 Coupe)

Steeda S550 Mustang Rear IRS Subframe Support Braces (2015-2019 Coupe)
$60.00 (20%)

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Product Install Instructions

With the release of the new 2015-2019 S550 Mustang, Steeda knew that addressing the IRS system would be a top priority. Being the first production Mustang with an IRS since the 03/04 Cobra's, we knew there would be a great opportunity to capitalize on Ford's new piece by giving it the Steeda advantage. As with any suspension system, deflection is an issue if it's present. Anytime a piece is moving, twisting or vibrating when it should be stationary is a major problem. One of the areas team Steeda wanted to focus on was the rear IRS subframe.

As you have seen with our IRS Subframe Bushing Support System, it limits the movement of the subframe by filling in the voids of the OE bushings. With Steeda's IRS Subframe Support Braces, we have taken the S550 rear suspension to another level!

Our Steeda S550 Mustang Rear IRS Subframe Braces for 2015-2019 Fastback coupe Mustang 5.0L GT, 5.2L GT350, 2.3L EcoBoost, and 3.7L V6 fastback coupe (non-convertible) is built in-house from 4130 chrome moly steel and powdercoated silver metal flake, this part isn't only strong - it also looks great under your new Mustang! What we did was tie together 3 very important points on the S550 chassis. We 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.

Also, unlike competitors kits that have not been released yet and only replace the factory bracket, our Steeda kit supports that bracket while connecting to 2 additional locations, therefore providing twice the support! Best part about this kit is it uses all existing holes in the chassis so the car doesn''t have to be modified in any way and adds no NVH whatsoever.

Product Benefits

  • Better handling for more stable cornering
  • Limits IRS sub frame movement
  • No permanent modifications necessary
  • No added NVH
  • 50% more connecting points
  • Reduces wheel hop
  • Lifetime warranty
  • Installation does not require removal of cradle

PATENT NO.: US D784,211 S

Purchase your Steeda S550 Mustang Rear IRS Subframe Braces for your Fastback coupe S550 2015,2016,2017,2018,2019 Mustang GT, GT350, EcoBoost, and V6 (non-convertible) at Steeda Autosports today!

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Fitment & Features


Manufacturer: Steeda Autosports
Made in USA: Yes

Installation Information:

Level of Difficulty: Easy
Install Time: About 5 Minutes
Tools Required: Basic Shop Tools
Print Instructions:
Install Video:

Vehicle Fitment:

Fits Model Year: 2015, 2016, 2017, 2018, 2019

Customer Reviews

Best thing to stop wheel hop
I bought mine before they had the “stop the hop kit” but the best thing I bought to get rid of wheel hop, and keep the tires planted down on the road or track. The “stop the hop” kit from steeda should be the second thing you buy for the mustang!!! (First being the jacking rails to make install of the kit easier)
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Reviewed by:  from Acworth. on 6/12/2018
Fantastic Product
I installed the braces in about 1hr using the list of tools provided in the instructions and it went smoothly with only 1 very minor issue! When doing this job I suggest that you tap the unused factory threaded holes prior to starting the installation they had some corrosion that didn’t allow the bolts to start properly. I took it out for a dirive after the installation and listened for any noises and drove easy . There were none . I then drove somewhat aggressively and the wheel hop was no longer there and the car felt much better as far as stiffness goes! This is a fantastic product and I highly recommend it to everyone!
Did you find this helpful?  6 of 6 Found Helpful
Reviewed by:  from Brooksville, FL. on 11/26/2017
Like these Support Braces
Installed these support braces a couple days ago using the easy to follow written instructions after viewing an installation video on u-tube. The install (driveway on jack stands) was easy and straight forward taking about two hours from start to finish. During post install test drive, the car felt much more planted on hard acceleration and definitely tracked straighter without getting sideways when shifting into second and third. No change to normal ride characteristics (harshness etc.) or change to NVH. Really like the planted feeling of the cars rear end when punching it. Recommend this item to help keep car straight when accelerating hard and banging a gear. No cons.
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Reviewed by:  from Gloucester Courthouse. on 11/25/2017
Quality Braces
Excellent pieces, worth the money. I was lucky enough to get a never-installed pair from a forum member for half the normal cost. I didn't buy them so much for wheel hop as rear end rigidity. I have a nonPP premium GT and have always noticed that there is quite a bit of movement in the rear end during tight cornering. It's not hugely noticeable but it bothered me. These braces completely fix that issue. They would've gone on in about 15 minutes with ramps but the middle bolt location on the car-side needed to be re-tapped from rust and road grime. If you have taps handy, just go ahead and ream out the hole with a 10-1.5mm before you start the install. I got the braces on and then had to remove them to get to the threads. Otherwise, no fitment issues as others have noticed. The rear end is a little stiffer ride than before now, but it's from parts not moving that aren't supposed to move, so I'll live. Exceptionally happy with the purchase!
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Reviewed by:  from Louisville. on 10/21/2017
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Reviewed by: (Verified Buyer)  from ORANGEBURG SC. on 8/3/2017
So much better
Put these braces on, and saw an immediate difference in the feel during a launch. Helps take the wheel hop out an tightens up the rear of the car. Thanks to Randy for all your advice.
Did you find this helpful?  7 of 7 Found Helpful
Reviewed by:  from Loganville, Ga.. on 7/10/2017
Review of subframe braces and vertical lengths
Recently had these parts installed at the Steeda facility in Valdosta, GA. and all I can say is WOW what a difference. First, let me start by saying my car is boosted and gets no traction on street tires and is an automatic. After, I picked the car up with my 7 year old son, of course we had to try it out. After, accelerating really hard at 25mph, my son looked at me and said, Daddy, it doesn't get sideways anymore. I looked at him and I said your rite. So, if your looking at any of these parts, I highly recommend them. You want be disappointed. Now, waiting to see what else Steeda may be releasing for the drag setup. Gonna have Steeda install the alignment kit and rear differential upgrade, next. Can't wait, one happy customer here. Thx. STEEDA.
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Reviewed by:  from Tifton, GA. on 5/25/2017
What a difference theses Steeda sub frame connectors made
Honestly, I did not think this suspension mod would do much for my slightly modded 2015 GT. The car has a CAI, GT350IM, long-tubes on back with 3.55 gearing from the factory. So not exactly a high horsepower car but enough to cause excessive wheel hop on throttle blips. What a difference theses Steeda sub frame connectors made, I was not expecting this. The car accelerate, within reason, without the back end jumping loose every time. Some better tires and it would really tie it all together in a very simple package. The coonectors are well made, high quality
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Reviewed by:  from . on 4/2/2017
you can add this subframe brace for not only extra wheel hop prevention, but also improved handing
There's always this debate as to whether S550 owners should get the competitors lockout kit or this for wheel hop. The most directly comparable solution from Steeda to the competition's lockout kit, IMO, is the IRS alignment inserts + IRS bushing supports. Then you can add this subframe brace for not only extra wheel hop prevention, but also improved handing and driver confidence on the street or road course. This brace also works in tandem with the aforementioned parts to keep the IRS straight and solid during launches at the drag strip and it does so from hard points on the IRS and using Ford factory subframe bracing locations, not with a bracket that slips into the IRS cradle bushing and with a steep angle connects to the vehicle frame with small 35 torque bolts going through slotted holes in the same direction as the movement its supposed to prevent. Look, they are two different approaches with a similar goal. I chose Steeda's solution because I road course my car and even a novice that's spoken to just a few seasoned road course vets knows that triangles make a subframe better.
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Reviewed by:  from . on 3/25/2017
no more wheel hop
I installed mine with the weight of the car on the tires (I have a 4 post lift). Everything lined up perfectly on the driver's side, the center hole was off just enough on the passenger side that I was concerned I would cross thread the fastener if I forced it but I was able to easily lever it into alignment with a screw driver.
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Reviewed by:  from Florida. on 12/10/2016
car should drive like this out of the factory!
I spend Sunday installing Steeda's front and rear sway bars (with billet aluminum sway bar bushings) on my 2015 GT PP. This is in addition to the progressive springs and sub frame bushing supports that are already installed. The installation of the rear parts were easy while the front was more tedious but not impossible for the average mechanically inclined person. I opted for maximum stiffness on the sway bars for the best handling performance. visibly there is a huge difference in the side and quality of the sway bars. Steeda's are much more stout and the bushing are significantly stiffer, the mounts are lighter (based on the standard mounts that come with the sway bars) but a much better design. The sub frame braces look like the perfect way to tie the IRS sub frame into the vehicle and "tighten things up". The brace connects near the jack points on each side to two points on the sub frame and one point in between creating a triangle for some serious stability. This is a tight fit so make sure you follow the instructions from Steeda and keep the bolts loose until things are set. I haven't had the car on the track yet, but there is a huge difference in just daily driving. I've hit a couple of curves hard and the car seems to dive into them and there is much more confidence in the car. I hit a pretty sharp curve the last 2 days on my way to work and I don't feel any understeer at all (at least I can't tell) I was doing between 60-70 mph through the turn it just felt nice! All in all I made a great choice. Steeda should have sold these to ford during manufacturing and the car should drive like this out of the factory!
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Reviewed by:  from Texas. on 11/9/2016
Completely different experience
I put the car to a slight test this morning on my way to work. I usually take this one turn at about 60mph and I can feel the car pulling, today I hit it at 70mph and the car felt like it dove into the turn. completely different experience in a very positive way.
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Reviewed by:  from Pennsylvania. on 10/14/2016
Totally happy
Installed this on my 2015 GT non PP in combination with Ford Racing Strut Tower Brace and G-Track Extreme. Car is exactly what I wanted. The car goes where I point it, and is very composed on rough roads. Went with 4 stars because one of the mounting locations just didn't line up. I had to again get the pry bar out to get the threads to start on the bolt. Not that big of a deal, but the install videos are not the norm. Used floor jack and jack stands and the install was just over 60 minutes. Totally happy.
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Reviewed by:  from Alabama. on 9/22/2016
the tires stay planted
I installed these braces on my EcoBoost recently and the difference was immediate! The rear is way more stable than before. I can push through sweeping corners and the tires stay planted. Now I gotta install my other Steeda parts and go back to the track to redeem myself.
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Reviewed by:  from Georgia. on 7/18/2016
Bye, bye wheel hop!
Today I added the Steeda Rear IRS Subframe Support Braces and Bushing Support system. It really made a difference stiffening up the suspension. I will install the Steeda Vertical Links next week. Bye, bye wheel hop!
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Reviewed by:  from Louisiana. on 6/10/2016
Tracks like a go kart now
On my previously stock GT non-PP i had a odd sensation while cornering that could best be described as a "rubber-band" feeling. I believe it was compliance of the subframe bushings. It was unnerving. Felt like the start of the tires breaking loose - but it wasn't. I installed the Steeda rear IRS bushing support kit and the IRS braces and the sensation went away. Much improved cornering afterward. I was inspired by the improvement so I added the Steeda springs and swaybars. Tracks like a go kart now.
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Reviewed by:  from Arkansas. on 5/1/2016
Car feels completely different now
Installed my Steeda G Trac Brace and Steeda IRS subframe brace. Car feels completely different now. Way more composed and even rides more smoothly over all the poorly paved roads and potholes in south east PA. The front end feels like it rides on rails now with the g trac and FRPP strut tower kit.
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Reviewed by:  from Pennsylvania. on 4/27/2016
Great item!!!!
Easy install, great item!!!!!
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Reviewed by:  from Louisiana. on 4/4/2016
Well worth it
The G-Trac brace and IRS braces areally both well worth it. G-Trac really helped tie my front end together and made a very noticeable difference going into the corners. Nice steering response gains. The IRS braces help tie the rear end to the rest of the car. Doesn't feel like the rear is walking out on you when you're getting into it and it seems to help with some of the deflection I was feeling, and made it tighter going into corners. You won't be disappointed with them!
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Reviewed by:  from Mississippi. on 3/30/2016
The car feels so much more planted to the road
This is the first time I've ever done anything suspension wise to my car, David @ Steeda helped out greatly with all my questions as well as getting me setup with an install at their Pompano location with a tour of some badass shop cars and their facility. Everyone @ Steeda - David, Patrick, Matt were great and made sure I was happy with everything. I can't recommend their shop enough to anyone in the area and Matt did an awesome job with everything on the install, even tack welded my Gibson exhaust and turned their clamps a bit to help out. I won't have a chance to do pics this weekend of my spot on the beach as that will give a good before/after comparison when I put them together. The car feels so much more planted to the road, even just turning out of their parking lot I could tell everything felt more connected and precise to what I was telling the car to do. It basically now goes where I want it instead of reacting to what I'm asking it to do if that makes any sense at all? I had some open highway and did a little bit of careful back and forth in my lane and I felt completely planted and not bouncing around back and forth in my seat. Almost found myself doing slalom in between some construction barrels but given how my morning went I decided against it. The springs give the car the look I wanted and make the Vossen wheels look that much better. Nice tighter rebound than stock PP springs and reduces the overall bouncy ness on some of those highway stretches where it feels like you're hitting hydraulics for a half a mile. Also any bridges or overpasses with rough spots where you enter/leave them were solid. The MT-82 bushing insert is noticeable and I had much easier downshifts for highway passes on the way home, feels like a much more solid shift that I had to get a bit used to in a good way. I didn't do any hard launches or try to break the rear end loose at all since I was just getting used to it, will report back later on that. I can't really report on some of the individual IRS components since they all went in at the same time, but I am noticing a slight (and I mean slight) gear wine from the rear with the Black bushings. It's only really noticeable if you try to make it happen and barely push the gas at cruising speed. Nothing I'm worried about and after 4 hours of driving it home windows down and up for a few sprinkles it does not bother at me all. It's not all the time either or in any specific gear so no biggie as far as I'm concerned.
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Reviewed by:  from Florida. on 3/27/2016
One of the biggest improvements to the handling of the car
One of the biggest improvements to the handling of the car is definitely the Steeda goodies all thanks to David here on the forum. He helped me so much picking out everything I should upgrade for all of the suspension parts to make this a great daily driver but also be able to take turns comfortably at high speeds and put the power to the ground. One of the first Steeda upgrades Slammered threw on for me was the Front/Rear Sway Bars and the IRS Support Brace and damn did it make a pretty damn noticeable difference in turning. No I don't track this car as of right now but the closest I get to taking turns and curves is off ramps from the highways and I've done decent speeds coming through those turns. The sway bars help keep the car planted and definitely boost the handling capability that the IRS already provides. I also installed the billet mounts and they look damn good with the blue sway bars and definitely are top notch quality over the stock mounts from Ford. Wheel hop has been one of the most notorious things the S550 platform has encountered with the new IRS system. Wheel hop is a "No no" and Steeda's IRS bushings are definitely the first step to knock out way more than 50% of the notorious wheel hop. When taking the bushing out of the box and taking a peek at my new goodies, I was amazed of the quality that is put into the manufacturing of the parts Steeda offers. IRS Bushing from Steeda is a must if you're looking to eliminate more the 50% of the wheel hop. It's great quality and definitely helps put the power to ground. When hitting it and shifting from 2nd to 3rd it's a whole new feel and it just takes off.
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Reviewed by:  from Florida. on 3/5/2016
Great job Steeda!
The rear sub frame braces are a great start to improving the IRS suspension. The rear end feels much tighter and there is no increase in NVH as stated by Steeda. Wheel hop has diminished when compared to stock and made a big difference. I feel that the braces joined with the Steeda G-Trac K brace up front will give the whole car a different feeling compared to the stock Performance Pack. Going around corners the car is well planted and makes a big difference in handling. I definitely recommend as an upgrade to the S550 Mustangs. Great job Steeda!
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Reviewed by:  from New Mexico. on 2/4/2016
Best suspension mod
The rear subframe braces are the best suspension modification next to the lowering springs. The rear is much more planted! Now I need the g trac k brace to tighten up the front end.
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Reviewed by:  from California. on 12/3/2015
No noticeable NVH
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.
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Reviewed by:  from Oklahoma. on 11/28/2015
I am a Steeda believer
The car is a totally different handling car. Took the wife for a ride today and she said it is smoother than before. Much less bouncy. That is good news to me. Cause if the wife is happy I am happy. But I will say that these mods have really changed my confidence in the car. I had one little 30mile spirited section with S curves on my way home that normally when they say 45mph.. you can take them at 55mph... I took them at 70mph and the car was just planted solid. No roll, no rebound and no breaking loose on the rear when I accelerated from the apex. It just transitioned smoothly and predictably. Now the only thing the wife did notice was the gear whine. Yes the Red differential bushing will cause some gear whine, but I have been told that replacing the stock gear oil in the rear end will help quiet that noise down. We will see as I will most likely change mine out here in the next week. Amsoil or Royal Purple is what a lot of people recommended. So, all in all, if someone is on the fence about these suspension upgrades, just do it. The guys at Steeda are top notch and know their stuff. Almost all of them have Mustangs and the owner even races them. A final shout out to [email protected] What a great help he was. He made sure everything was ready and there, his recommendations were spot on. David, again, Thank you man. I can hardly wait for the next batch of Steeda goodies come out.. Count me in already. I am a Steeda believer.
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Reviewed by:  from California. on 11/13/2015
There are no reviews for this product!

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