[Unclesams_svt]

I made a small list of items that I wanted to do to right off the bat to my new-ish Shelby.

I ordered the following items:

Jacking rails -- Steeda 555 5212 Mustang Coupe Full-Length Jacking Rails (15-22)

IRS alignment kit -- Steeda 555 4438 Mustang IRS Subframe Alignment Kit (15-22)

IRS Brace -- Steeda 555 5754 Mustang Coupe Rear IRS Subframe Support Braces (15-22)

Install for all of these parts is easy and pretty straight forward. Install the alignment kit before the IRS brace to prevent you from installing the braces twice.

I installed the jack rails first by getting creative with my quick-jack and jack stands.

I then was able to loft the car back up and installed the bushings and IRS brace.

Be sure you double check the bushing orientation as there is a relief cut on one side for the bolts (the picture shows the difference)

Wrong way

Correct way

The rest of the install is easy using the instructions from Steeda below

This is the reason I did this, you can really see the difference one the bushing is inserted.

loosey goosey

good and snug

 

[AZ21GT500]

I made a small list of items that I wanted to do to right off the bat to my new-ish Shelby.

I ordered the following items:

Jacking rails -- Steeda 555 5212 Mustang Coupe Full-Length Jacking Rails (15-22)

IRS alignment kit -- Steeda 555 4438 Mustang IRS Subframe Alignment Kit (15-22)

IRS Brace -- Steeda 555 5754 Mustang Coupe Rear IRS Subframe Support Braces (15-22)

Install for all of these parts is easy and pretty straight forward. Install the alignment kit before the IRS brace to prevent you from installing the braces twice.

I installed the jack rails first by getting creative with my quick-jack and jack stands.

View attachment 242577
View attachment 242576

I then was able to loft the car back up and installed the bushings and IRS brace.

Be sure you double check the bushing orientation as there is a relief cut on one side for the bolts (the picture shows the difference)

Wrong way
View attachment 242580

Correct way
View attachment 242579

The rest of the install is easy using the instructions from Steeda below

View attachment 242581

This is the reason I did this, you can really see the difference one the bushing is inserted.

loosey goosey

View attachment 242582

good and snug

View attachment 242583

I’ve done exactly that, my question how did you like those absolutely planted launches after 😂😂😂

 

[Unclesams_svt]

The IRS brace was also a simple install (unless you do what I did the positioned the quick jack to far aft so it covers up the 2 forward bolts 🙄

I loosely installed all the bolts before running anything down tight. The rest was just as the instructions below stated.

Everything loosely installed and checked for fitment.

Do not be this guy 🤪

The only bolts that do not use a factory location.

 

[Unclesams_svt]

I’ve done exactly that, my question how did you like those absolutely planted launches after 😂😂😂

I only drove around the block to make sure all was good, I am going to get the car aligned this week and then I will "test" to make sure it passes the "heck yeah" reason for spending the money.

 

[AZ21GT500]

I only drove around the block to make sure all was good, I am going to get the car aligned this week and then I will "test" to make sure it passes the "heck yeah" reason for spending the money.

Mine absolutely launches like a bat out of Hell on fire being chased by people from Covid town. 😂

 

[mavisky]

Nice work. Basically the same setup I have on my GT350 and the rear feels so securely attached to the car, but the change in the alignment from the dowel pin correction was shocking.

 

[AllShelbysAntimatter]

im shocked this would happen on a car like this from factory. does the car actually feel better with the braces and alignment kit? you wouldnt think a gt500 would need one

 

[AZ21GT500]

im shocked this would happen on a car like this from factory. does the car actually feel better with the braces and alignment kit? you wouldnt think a gt500 would need one

The IRS system in the S550 Mustang lends itself to a comfortable driving experience until you are putting the power down hard. That’s when it becomes hoppy and loose. These help button everything up and removes the negative effects of the IRS system.

 

[Unclesams_svt]

Nice work. Basically the same setup I have on my GT350 and the rear feels so securely attached to the car, but the change in the alignment from the dowel pin correction was shocking.

The next drive will be straight to an alignment shop for this reason.

 

[Unclesams_svt]

im shocked this would happen on a car like this from factory. does the car actually feel better with the braces and alignment kit? you wouldnt think a gt500 would need one

The IRS subframe and bushings looked just like my buddies 15' GT, heck the control arms even looked the same.....so I do not think Ford looked into bracing or new bushings for either cost savings or for the ride comfort.

 

[mavisky]

im shocked this would happen on a car like this from factory. does the car actually feel better with the braces and alignment kit? you wouldnt think a gt500 would need one

It depends on how sensitive you are and how hard you're pushing the car. I noticed the slop in the rear the most with mid-corner corrections or some of the mountain roads up our way where the corners can sometimes decrease in radius mid-corner. When making that secondary steering input I could sense a shift/delay/pause in how the rear of the car would be gripped up, then take a split second to adjust to the new steering input.

I noticed it again in transitions, but here it was masked more than the mid-corner incidents. To me it felt like the chassis was riding "on top" of the rear IRS and it was clear that they were two separate units. The dowels correct any alignment (but also require a rear suspension re-alignment) and the bracing helps solidify the ability for the IRS to move separate from the unibody by triangulating the attachment points. They're cheap mods, don't increase NVH, and in my opinion are a win/win solution.

 

[bent98]

I’ve done exactly that, my question how did you like those absolutely planted launches after 😂😂😂

You should also consider doing this as well

Steeda 555 4437 Mustang IRS Subframe Bushing Support System (15-22)

Steeda S550 mustang IRS subframe bushing support system for your 2015+ Mustang GT, EcoBoost, and V6 gives the rear end a solid feel with no increase to NVH. The Steeda IRS subframe bushings eliminate rear subframe bushings eliminate subframe movement.

www.steeda.com

 

[AZ21GT500]

You should also consider doing this as well

Steeda 555 4437 Mustang IRS Subframe Bushing Support System (15-22)

Steeda S550 mustang IRS subframe bushing support system for your 2015+ Mustang GT, EcoBoost, and V6 gives the rear end a solid feel with no increase to NVH. The Steeda IRS subframe bushings eliminate rear subframe bushings eliminate subframe movement.

www.steeda.com

I looked at that kit because one of my buddies has it. We did some driving with a go pro watching the IRS and it didn’t seem to make that much of a difference so I held off on adding it.

 

[bent98]

I looked at that kit because one of my buddies has it. We did some driving with a go pro watching the IRS and it didn’t seem to make that much of a difference so I held off on adding it.

It helps if you plan on dragging the car. Reduces subframe flex by 1/2”

 

[mavisky]

It helps if you plan on dragging the car. Reduces subframe flex by 1/2”

I've seen that on a GT, but the Shelby cars use bushings of different durometers. Was that measured on a GT350 or GT500?

 

[AZ21GT500]

It helps if you plan on dragging the car. Reduces subframe flex by 1/2”

I don’t intended on dragging it. It’s not a bad idea to add them. I just pushed it back to my maybe list 😂

 

[bent98]

I've seen that on a GT, but the Shelby cars use bushings of different durometers. Was that measured on a GT350 or GT500?

On 500 there is no issues and it takes up the slack of the IRS. On the 350 you can’t use all the bushing

 

[rxsamg]

So I’m not buying a GT500 to ride like a Lincoln but I’m curious if any of you notice any harsher ride at all when you’re out cruising. If you take out some of the chassis flex would that be a bit of a side effect?

 

[bent98]

So I’m not buying a GT500 to ride like a Lincoln but I’m curious if any of you notice any harsher ride at all when you’re out cruising. If you take out some of the chassis flex would that be a bit of a side effect?

No, it doesn’t add any NVH, however if you do the differential bushing, it will make the ride harsher . I don’t suggest you do these below.

https://www.cjponyparts.com/steeda-rear-differential-adjustable-bushing-insert-system-urethane-mustang-ecoboost-gt-2015-2022/p/5554439/?year=2019&gclid=EAIaIQobChMIyNCEypSo-QIVncmUCR2S-wo1EAQYASABEgLQ6vD_BwE

 

[mavisky]

So I’m not buying a GT500 to ride like a Lincoln but I’m curious if any of you notice any harsher ride at all when you’re out cruising. If you take out some of the chassis flex would that be a bit of a side effect?

I haven't noticed any additional harshness.