I have one on my Project SuperCobra, but mine is made by BilletFlow.
Highly recommended by the 03 Cobra crowd.

It fits with some grinding !

avoids scenes like this:

[ May 10, 2005, 02:38 AM: Message edited by: SuperCobra4Me ]

 

Technical Foul!! Sergio is penalized 10 posts for scaring the $hi+ out of another forum member and causing him to spend additional money .

That is a very frightening shot. I'll be calling Steeda today. And I thought the irs was, at least, one part of my build that was complete . Thanks for the heads-up guys.

Matt

 

I'm not saying it can't happen in our cars... but, I suspect that the rubber mounting arrangement has a lot to do with this failure in other cars. If the front and rear are solid mounted, I think it is less likely to happen. I can see this happening to builders that use the stock rubber mounts in the front with a solid mounted rear, though...

Brian

 

Here we go again. I have a solid front mount. What the hell, I am ordering one, based on the premise that I am defenseless when it comes to adding just one more thing to make it better. Car is coming today. Why install after the fact......

Axiom: Those of us who worship at the feet of the forum shall go over budget.....

 

I guess I'll be calling Steeda this week.

 

Ok we have had 0 problems with the IRS. I have customers running 10s (10.87) and 11s (11.34) with no problems. The only problems I have heard of is the occasional shaft breaking. There is another replica using the same housing and they were breaking axles and not the centers. Remember, the car is almost half the weight of an 03 Mustang. HTH, Cheers Richard.

 

One thing about the rear center section reinforcement if used on a FFR chassis, the "ears" on the chassis that bolt to the rear end cover are spaced apart just enough to allow the casting to be captured. By adding the steel support, you will have to bend the ears further apart to allow for the thickness of the support. It may also induce stress in the casting from the steel support, if everything is not lined up exactly. It will probably work on a Mustang, but they use a different rear mount design.

 

I trust there's a hole punched in that brace so you can get to the filler plug on the rear cover.
Frank

 

The hole is there.

 

I think the reinforcement goes on the outside of the ears. No bending is necesary.

 

I would take Richard's practical experience over a company trying to sell yet another part.

 

as many here had said, I don't think it can happen in our cars being so light, it was just another part that fits in the "What if I end up with a 700 HP engine in the future" Category, which I intend at some point in the future (If funds allow) to accomplish... 700 HP that is....

By looking at the image from Steeda, that part would be more dificcult to grind, the part from Billetflow that I have is more sturdy and has quite some meat to remove while grinding. unfortunately seems Billetflow is making another batch and are out of them right now....

 

boB - before you buy, you may want to have a look at this thread to see what I had to do to make the Steeda cover brace fit the T-bird IRS.

 

what Paddles had to do to the Steeda brace illustrates my point, the Billetflow piece I got fits with only some grinding on the face that meets the 2 rear mounting bolts to the FFR frame.

 

Seems like a waste to me as well. I don't care if you have 700 HP or 7000 HP; if you can only get 350 HP to the ground, that's the stress limit of the rearend. I'll take a guess that these things get broken from popping the clutch and drag racing more often than simply driving the car.

 

2 Questions and one comment.

Who has broken a center section that WE know?

Is the brace an excuse not to drive your FFR or merely another $ignture line item?

Comment. I spent 30 minutes Saturday in a new 392 stroker, aluminum center section FFR on new Hoosier slicks. Nothing broke and I got tired.

Roger

 

Roger I feel the same way about all these people purchasing scattershields. how many of us have ever lost a clutch?

 

I see it as different Michael. A clutch goes and it can be EXTREMELY nasty. A diff goes and while expensive....not the end of the world.

 

$165.00 + shipping

That is more than half the price of my entire IRS

 

The pic of that busted diff could be from a driver side axle hit. The rear cage mount appears bent. Who knows?

 

I started thinking about this last week. I was up in Denver talking to Carl Wade, a Cobra racer from way back. His son owns S&S Automitve www.coloradocobras.com They work on a lot of Cobras, and build and race Unique Cobras.

We were looking at an SPF (very nice), and I asked him what he thought of them. His only negative comment was the rear diff. He said he's replaced 3-4 of them in the last year, beacuse the housing breaks. The Superformance uses the same alum T-Bird diff that we do. Since I was thinking about it, the ad caught my eye.

So I sent an e-mail to Steeda asking if they thought this would fit. Amazingly enough, I got an answer back the next morning! Anyway, here's the exchange:

My letter to them:

I was looking at this part, and I am wondering if this will fit my application

I am building a Factory Five Racing Cobra replica. I have installed an IRS. The IRS uses a T-bird 8.8 differential center section, 1989-1997. I understand this differential is the same as the Cobra. I look at the picture on the web site, and my differential, and they appear to be the same rear cover. My only concern is the frame mount. On mine, there is a frame bracket that sandwiches the two bolt mount on the differential cover.
In the picture on your web site, it appears there is a spacer plate between the bracket itself, and the mounting boss of the cover. If that is true, I believe it will fit. If the bracket is mounted flush to the mounting boss, then it probably will not.


Answer from Steeda:

The spacer plate you ask about that is used in the installation of the Steeda IRS brace is 0.188” thick. We have never attempted to fit this brace to a Thunderbird IRS. Although it is commonly believed that the two unit are identical, this is not true. Still they are very similar, especially at the rear cover.

---------------------------------------

So, where does that leave me? My engine will make pretty close to 550hp. I used a cast iron center section, because it is probably a little stronger. I also used solid alum front mounts, because I wanted to match the solid mount of the rear.

If I decide to hit the drag strip a few times and really hammer it, am I going to break the rear cover? One expert voice says yes, and one says no. I guess I'll just wait and see.

 

The part has it's merits and is mainly needed in heavier cars such as the Mustang, T-Bird, and MK VIII. These last two do weigh double what a complete FFR weighs. The FFR might still benefit from it, but it doesn't need it. As said before, these cars are so light that they'll spin the wheels and lose all traction before they're likely to do the sort of damage shown above.

 

boB, if you decide to buy one, you could always swap the rear cover for a Cobra one. That is a direct bolt-on. I have a couple of different aluminum pumpkins, and they are both slightly different externally (different ribs on the housings, and covers). On the inside, they are the same. One is a '99 Cobra, and the other is from a Lincoln Mark?. So, if you buy it, and it doesn't fit, at least there is an easy solution.

Personally, I could see the halfshafts letting go long before the center section...

Brian

 

Who is smart enough to tell us the forces applied on this? Maybe one of the lb/ft ft/lb guys could take a look at this for us. Maybe it's not that much and the cases break because they are cast poorly or something?

 

Someone who has one and is a cad/fea expert could figure it out easily. I dont think the brace is necessary if you solidly mount the front of the pumpkin. if the front is rubber mounted and rear is solid most of the force is going to be on the rear.