Club Cobra - Independant Rear Suspension

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Independant Rear Suspension

I have read some articles about installing a Mustang Cobra independant rear suspension in place of the standard Ford 8.8 straight axle. The articles seemed to say that the Mustang Cobra IRS subframe/carrier would bolt to the same mounts as the standard rear end. It seems like the only modification might be a drive shaft length adjustment and a different differential spline to drive shaft adapter. I also see a couple of brackets on the IRS subframe that might need to be bolted to the car frame

My question is has anyone done this on their CR Cobra? Is it that easy?

Thanks

Rick Neilsen
Early CR with 302 5 speed

No, it's not that easy. The big issue is width. Kits made to bolt in to a Mustang are a bit wider than a Cobra kit. To solve that problem, FFR designed shorter arms and shorter axles.

Also, the Mustang is a Unibody. Although the pick and mounting points are the same, the design of the frame is very different.

FFR has a bolt in kit for their cars, but it's very different than what fits in a Mustang

It can be done, of course. But it won't be a simple bolt in operation.

Doesn't the CR kit use a standard length axle that is out of a Mustang? I didn't build my car so I don't know. Maybe the newer Mustang Cobras are wider. If I buy a IRS out of a Mustang Cobra wouldn't that be the same width? There are a bunch of these becoming available on E-Bay for around $2,000 as these cars get older. They also like the straight axle swap because strait axle is supposed to be better for drag racing. In the photos of these IRS assemblies one pair of mounting points looks like it might need a adapter but again I don't know. Just asking.

Thanks

Rick Neilsen

Rick,
If I may.. I saw your post when you immediately posted it. Didn't say a thing because I figured they would let you know soon enough.

To keep things in the family FFR and CR are two complete different animals, both Cobras but that is about it.

Listen to these guys. it CAN be done but by gawd you better be really good at suspension Geometry, fabricating and certainly have your check book out!

My 2 cents ....

DV

$2000 is way too much for the IRS unit. A buddy sold a 28 spline version a few months ago for $500....complete.

Geesh! I get more than that for a lincoln 9" posi!

I'm still thinking about a Independent Rear Suspension (IRS) for my Cobra. I talked to DV about this again. He said he wanted to see the articles I was talking about. I don't have DV's E-Mail address yet so....

The following link is a You Tube video of a 2003 SVT Cobra (Mustang) IRS being swapped into a 1991 Mustang LX that had a straight axle. The mustang IRS is attached to a carrier that bolts to the lower straight axle mount in the front and shock mounts in the rear. The video shows a small modification needed to the uni-body on the 91 mustang. It would seem that a similar mod or a bracket could be made to attach the rear of the carrier to the "frame" of a CR Cobra. Note! there are no modifications to the width (wheel base) of the IRS in this video. Also there are no geometry changes. There might be a need to change the wheels with a different off set but that isn't clear. My CR Cobra has a axle from a 89 mustang. [ame]https://www.youtube.com/watch?v=VOhGkCe5rDw[/ame]

The following link is a write up of the instructions for installing a Ford Mustang Cobra IRS into a Mustang that had a straight axle. https://www.v6mustang.com/threads/ir...ite-up.243265/

I don't have the knowledge you guys have with Cobras and that is why I'm asking.

Take a close look at that picture, and then take a close look at your car. Bolting all that in to a Mustang is actually pretty easy. Most of the mounting points are already there, and the one's that are not are fairly easy to add. It's not quite a "simple bolt on", but close.

In your Cobra, though........

Buy a another Cobra with IRS.