IRS Install in a fox-body Mustang
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- เผยแพร่เมื่อ 9 ม.ค. 2025
- This video is about the installation of a 2003 SVT Cobra's independent rear suspension into a 1991 Mustang LX. Muscle Mustangs & Fast Fords magazine followed the process and wrote up a tech article for their June 2013 issue...titled, "Declaration of Independence".
That's crazy, and it only took 9 and a half minutes! I'm gonna do this on my lunch break!
Y'all made this video much more complicated than an IRS really is. I took less time putting mine in than taking the old one out. I only welded the rear brackets for strength after bolting it right in. 90LX 5.0 with 04 IRS = no hassles.
How much time did you have in the swap said and done?
For those of you who want an IRS, RideTech is just about to release an IRS utilizing S550 parts. We'll see how good it is but it looks like a better design.
Me and a friend did this IRS swap back in 2008 to his 86 saleen..... Should've called FF and MM magazine then about it if we new you guys were gonna cover it like this, and we did it without a lift( that was fun)! The swap isn't that hard but more tedious than anything.
Thanks for the simple way to share your skills. From Hermosillo, Sonora, Mexico.
LOVE IT! I have the magazine and the video helped confirm the decision of this conversion for my fox Mustangs! Thanks!
There are many reasons to want an IRS. For daily driving it gives a much better ride quality. For racing you can get better handling, add more camber and it will also add rear disc brakes a new cat-back and gear ratio.
Great video. I might be building a foxbody for road racing one day soon, will most likely be doing this.
Getting ready to document an IRS and brake swap from a 2001 SVT Cobra to a Foxbody Coupe project.
Really nice job. I want to do this in a Foxbody hatchback. Seems the way to go.
The drivers side tire looks like it is further in under the fender than the right side. That is more outward. I notice this on. A lot of these installs.
Yes, it did...a big improvement. Not only because of it being an IRS. But now, camber & caster can be adjusted in the rear. This is not possible on a SRA.
It's about a full day install, granted no other projects...just an install. And ride comfort greatly improved with better handling overall.
this should be very similar for 94-98 mustangs right?
They are the clear lenses from LRS or American Muscle. But the I installed LED panels made from this guy. I have a write up on my Blog. The site is in the video
Watching in 2023!
Cool vid and nice to have IRS in a fox body!
do you remember the "after" weights?
As always great work from real speed.
You guys should sell the custom brackets that you fabricated in order to mount the IRS subframe.
I think I remember a company made a tubular subframe and arms for the IRS swap that was a lot lighter and used stock holes. Anyone remember who it was?
Chris Madsen kenny Brown
Did the IRS improve the handling over the TA/Panhard bar setup?
I think it's funny how they say "have all the parts" but they don't go into depth about what parts specifically like a parts list, you know for the novices and such...
ill be taking all those old MMsports parts of your hands :P nice video!
It was better than the IRS they installed...!
they made it look simple, done right!
and did it improve the handling of the car? What are the pros and cons in your opinion? I've heard that it gets heavier and tends to pull on the back precisely.
Correct. It's not an improvement, it's just a heavy piece of jewelry.
So I've got the IRS rear end and shocks. I am missing the brackets and springs. Springs are easy, and I see I can get the brackets online, but at $150-250 I feel like there should be another option. That stamped steel seems weak and could be fabricated better?
Yes, rear track width. And yes, a much improved ride comfort. Sorry, not familiar with the 4-eyes foxes to give you an answer.
Nice job guys!!! How much will a job like this cost on a 95 cobra???? Is the ride confort affected and how????...great video!!!:-)
Instead of modifying the bolt holes to work could I just weld that bracket on to my car
I dig it. Just don't dig IRS and "Convertible" lol. Still a pretty sweet ride.
Yes, I answered that question below. Sorry, I don't haven exact price.
This is great, I wonder if It can be done with a Thunderbird IRS?
Junkyard Doggs I've been trying to find information on it but I can't find it anywhere
Will the TBird IRS fit in a Mustang??
That looked like it was a complete nightmare to install. I wouldn't do it in my garage on the ground .
I did this with a buddy in his garage, was quite easy actually. We had a jack and that was about it.
When you said wheelbase, did you mean to say rear track width?
Nice video, was the ride, as in ride comfort, much better with the IRS? And, any thoughts on a pre- '85 fox body, as the pick-up points for the control arms were changed slightly in "85.
Good job!
NICE, but Has this suspension sway bar? i didn´t saw it, You should not wear?
Instead of doing all that cutting and welding, wouldn't it be possible to make new custom brackets that utilize the stock foxbody holes?
You still have to cut & weld. The IRS requires 3 holes and the fox body only has 1 that lines up. No matter what, you have to drill 2 extra holes. There are a few ways of doing this. This was Real Speed's solution.
Buy a junked 90's thunderbird and put a Cobra engine in it. IRS problem solved.
Just did last week
My car has IRS, can I put springs that don’t fit cause of it?
i have a 91 vert GT i might be interested in doing this,problem i see is people here are talking about 2003 cobras like they grow on trees,are 2003 cobras the only place to get a irs like that and did they make that many of them that are wrecked?
Ford installed IRSs on all 2001-2004 SVT Cobras
ReelSpeedProductions 99 svt cobras had IRS as well
Alex Lester same with 2000 cobra r's and the rare aussie right hand drive 2002 cobra
+ReelSpeedProductions and lmr sells the kit
I noticed the Anderson bumper sticker on the box back there. That's from my hometown of 1500 people..where did you get that?
I believe that is from Anderson Ford, they were a huge factor in fox body racing back in the day.
ReelSpeedProductions That he was...his son races a coyote fox now. small world
John Smith Smaller...Realspeed's friend/customer Mike Washington also competes in Coyote Stock. LOL
ReelSpeedProductions Nice! I would have never thought somebody on the East coast would know about Ron during those early days. A family friend was a big engine builder back then with Anderson, and now he works for Roush building engines. I keep bugging him about being on a pit crew.
For street driving, how do you compare the irs to the mm ta&pb?
I know the this video is old but will an IRS 8.8 form an 1989 to 1996 cougar or thunderbird work instead of useing a cobra IRS since I all ready have one from a 91 cougar.
Good question...but sorry I do not have the answer.
I bet it rides alot smoother
can you still use the rear springs off the fox or do you have to get some cobra ones ?
Sam Lockman they are the same
Did you have to do anything to the driveshaft, I’m doing an irs in a foxbody and the only thing I’ve ran Into is that the driveshaft seems slightly to long now.
Yes, IRS driveshaft has to be cut down a bit shorter. Rob measured it out and had a shop cut & balance it.
Yes it does. It's great.
Hi there. Hey ReelSpeedProductions guy, Is this rear exactly the SAME PARTS from the 03 cobra rear or did you upgrade the half shafts and internals inside the pumpkin? What size gear are inside as well as the posi unit and all that good stuff? Also is the independent pumpkin the same size as the 8.8 solid axle rear that was pulled out and swapped? Meaning the same internals can fit from either rear? For example if you want to buy a aftermarket posi unit with 33 or 35 spline axles, are there 33/35 spline half shafts to match?
I wanna figure out how to put an irs in my foxbody and I get a cheap metal song stuck in my head thanks guys
I don't have an exact price on the install...sorry. I had other work done, plus I traded my old parts in and with the mag covering the project...I got a nice discount. But, it's about a full day to install without any rebuilding of the IRS.
only on fox platform cars, not on s197 (05-14)
So how does the Cobra IRS handle compared to the torque arm/panhard bar setup?
The IRS is better all around. Biggest difference in daily driving, for sure. With a bit of work and bushings the IRS is all-around better...except for drag racing of course! Just look at the Mustang today, Ford went as far as it could with the SRA in the Boss 302, and now the 2015 has the IRS. Watch how far they go now, if they only switched over sooner. They're behind now, thats why the new Camaro always gets better reviews for handling.
+ReelSpeedProductions
mustangs is not a pickup any more this is a good new way the go for it mustang now not a muscle car it is a pure sport car and i hope they lunch the fox body again
Hi guys, what about Mustang 5th Gen ???
is there a website i can buy kit all in one???
Can you do a coil over kit on the foxbody irs swap?
I did. I installed single adjustable Koni coil-overs.
@@ReelSpeedProductions did you make a video of it?
Graigory Gilbert no sorry, the coil-overs were installed during the video but not shown. It’s simple bolt-in procedure, nothing special.
what brand coilover did yall use?
Yes it is.
you have to upgrade the bushing to eliminate wheel hop. too soft from factory.
what was the point of putting it in a convertable
to enjoy the ride my friend.
plus you dont put irs system in a car, unless you drive that shit everyday. he probably drives it on nice scenic routes or something...those irs systems cant handle more then around 450hp anyway without being upgraded or changed out. So I dont think he's looking for big power, a nice daily driver...I might put on into my 00' sixxer. direct fit...and why not lol
Do you guys have a link for that T fitting i cant find it anywhere. Thanks
That t-fitting for the brake line is found at any auto parts store. Not a hard item to get.
Hi I was thinking about doing an IRS swap for my 04 mach 1. I can't find any proper custom shops in my area. Could I hire you guys to do this for me?
Jack stereoclock I'm actually a customer...you should go to their website and contact them. I'm sure they would. They have done a ton of them since. Even out-of-towers. Www.realspeedautomotive.com.
Those of you that are actually looking for information on how to do this......the "how to" starts at 4:00.
So where does the gas tank get relocated to?
Gas tank does NOT get re-located. Only removed for IRS installation for more room. Gas tank gets installed with stock straps in stock location.
Did it help your weight distribution?
Yes, very much so. If your going to add additional weight, the rear is the place for these cars. At the same time, the IRS also saved significant unstrung weight.
ReelSpeedProductions
So what is the before and after weightdistribution?
Did you guys use Sn-95 axles or spindles?
Yes, upgraded to SN95 spindles. Pushed the wheel out a tiny bit. I still have 17x8's so no rubbing.
I want to upgrade my 1990 Foxbody to 5 lug and the track width on your mustang before the IRS install is what I want on my fox. I really like the project and how it turned out. Thank you guys!
How do u keep the rear tires from rubing on rear panels
Easy, have rear wheels with proper offset & backspacing. Front wheel Bullits are from a SN95 and the rear Bullits are from S197 Mustang...they have a +45mm offset and 6.295" backspacing. These had no rubbing issues.
Roll the lips, Eastwood tool
Im doing an irs swap in my fox in a couple of weeks just got my irs off a 2003 cobra..
How much did the IRS cost you?
Jeremy Kline
Can usually get them for under 1500. There not great for launching or drag racing and will slow the car down. If you want a road course car get the IRS. Best of both worlds is a watts link or panhard par with a solid axle like the new Boss302
id love to do this on my 93 fox...how much?
i really love those wheels
How much was the install and parts?
What is the weight difference?
It's approximately 150 lbs heavier.
they said 48 [punds at the end
Can this be done with a 2012 gt?!?!
I was lucky and got a 04 cobra IRS for $1,900 and if I want to send it to Kenny Brown for carriage alterations so it doesn't have bump steering problems $1,300 then you want to get a bushing kit $1,300 want to make sure it has no overheating issues $1,300 for the kit. With new brake pads and lines your in at $6,000 and it's not even on the car..🤯🎉
That was awesome!
i just bought a 2003 cobra instead of doing this to my fox the IRS is somewhat noticeable.
oh and if Tire sticks out further on the left side then it does the right to so you ain't got it in their Center
I already answered that in a previous comment
are you able to fit wider tires on this car now?
..... Now let's see if they can install this IRS into a Fox Lincoln????
How does it feel on the road???? How much better is it???? How much did you pay for the install and man hours??????
Big difference over stock, and a much better ride overall.
Beautiful car
Why would this be needed?
I doubt there was any increase at all in performance going from a Panhardbar/torque arm setup to the lack luster IRS from the cobra mustangs. All the car gained was ride quality and a less stable straight line performance.
They are building it for autocross not drag racing. Hence the license plate.
Obviously i didnt think they would be drag racing with an IRS The COBRA irs has little to no performance improvement in autocross over a fully supported live rear axle.
+H1shman Then why did they go to IRS in 2015. Many people have said it hooks better than the SRA
i'm up for the challenge ^_^
was it really better?
Nope
dude, IRS is not intended for drag racing especially competitive racing so obiviously it would suck
I wish I could install one of these in my '93 Cobra, but my replica five lug wheels would stick out too far. No way around that.
buddy did it and said it sucked for drag racing
too much wheel hop
That's so cool
Well its not in the previous comments the time you wasted by not telling me you, could've done it by now...
Kinda off topic but what's the name of the song towards the end? I tried looking it up but the results give me the molested version by Ernest Vogue which contains his shitty voice-overs.
Never mind seen it.
I dont think so.
oh
Sorry, not an installer.
what is the point there is none.
#mute
looks like a lot of unnecessary work if the car is that mint underneath, watched a video on TKO RESTO's page the other day and his made a lot more sense and quite a bit better quality of work didn't have to use a single dead blow hammer or he at least didn't film that... if i was spending the money on an IRS i definitely wouldn't want all that cutting and welding on my ca. Definitely wouldn't have them install mine like that.
5:34 makes me cringe...... You can do better my friend! At least make it symmetrical.
Hacking up a good fox, waste