"THE" Cobra IRS thread

ac427cobra

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I've always tried to give good solid advice regarding the Cobra IRS. It unfortunately was more than a bit compromised as delivered from the factory which has caused many people to dislike it. But there are fixes for it.

Recently, Ford Racing came out with a reinforced differential cover for the IRS. It's a much improved design compared to the egg shell thin OEM cover and I believe this will be the standard for the future.

There is no issue installing this cover with the OEM rear diff support bracket. However, I would not recommend retaining the OEM rubber or even an aftermarket poly bushing. Delrin is the only choice of material if you want to use the rear OEM mounting bracket.

If you have a driveline vibe in your car you are going to want to use a lowering rear diff mount so you can fully optimize your driveline angles. Something you can't do with the OEM rear diff mount.

If you want to combine the lowering rear diff mount AND the new Ford Racing IRS diff cover, you WILL run into clearance issues with the inner toe link mounts on the subframe. We have an answer for you if you plan on combining those parts. We are now offering a Ford Racing IRS cover that is milled for clearance so all you have to do is bolt your parts in place with no worries.

Here is a photo of us making some chips last night on the milling machine:

MillDiffCover.jpg


This is what the clearance looks like on the right side:

MillDiffCoverRightSide.jpg


and on the left side:

leftmilling.jpg


As you can see, the left side needs considerably more clearance which can be seen in the photo of the milled cover we now offer:

milled%20cover.jpg


Here are a couple of photos so you can see how the inner toe link mounting brackets on the subframe interfere with the lowered cover:

MilledDiffRightSideClearance.jpg


MilledDiffCoverLeftSideClearance.jpg


Four machined covers being shipped today to four happy FTBR customers:

CompletedDiffCovers.jpg


Machined Ford Racing covers part number FT 1350M can be found on our order page:

Full Tilt Boogie Racing Shopping Cart

I'd be glad to answer any questions anyone might have.

:thumbsup::coolman::beer:
 
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mach1033

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looks excellent Bruce. I have your full IRS kit installed in my car so I assume I need this done when I plan to upgrade the rear diff?
 

shb5007

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I don't plan on ordering the FTBR bushing kit (5001) until this fall/winter...but I want to upgrade my rear diff cover now...so you will be getting a call from me about a milled Ford Racing diff cover real soon.
 

ac427cobra

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looks excellent Bruce. I have your full IRS kit installed in my car so I assume I need this done when I plan to upgrade the rear diff?

It depends on whether you have the FT 5000 or the FT 5001 kit? If you have the FT 5000 you are fine. You won't need the milling done to your cover if and when you upgrade your cover. But, if you have the FT 5001 kit with our Delrin isolated rear diff lowering mount then yes, you will need a milled cover for it to bolt in place without issue.

I don't plan on ordering the FTBR bushing kit (5001) until this fall/winter...but I want to upgrade my rear diff cover now...so you will be getting a call from me about a milled Ford Racing diff cover real soon.

Just as a heads up, the Ford Racing covers are on back order right now. We are sold out of all of our covers at the moment. We are being told the end of January is when we will see our next shipment. So plan ahead!!!

:thumbsup::coolman::beer:
 

TRBO VNM

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Very nice Bruce. I should be paying for those 2 kits this weekend or Monday at the latest. But these two guys opted to stick with their current setup(IRS Brace) for now.

BTW, looking at the second to last pic, is there any clearance room between the cover and rear support bushing? Appears they are touching?
 

mach1033

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It depends on whether you have the FT 5000 or the FT 5001 kit? If you have the FT 5000 you are fine. You won't need the milling done to your cover if and when you upgrade your cover. But, if you have the FT 5001 kit with our Delrin isolated rear diff lowering mount then yes, you will need a milled cover for it to bolt in place without issue.



Just as a heads up, the Ford Racing covers are on back order right now. We are sold out of all of our covers at the moment. We are being told the end of January is when we will see our next shipment. So plan ahead!!!

:thumbsup::coolman::beer:

I ordered your kit back in the spring of 09 did you have the 5001 kit then?
 

oldmodman

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Hi Bruce!

I have the FORE Billet Diff Cover. Haven't tried to install it yet.
Will I have any problems using it with your bushing kit.
I have the complete FT5000 kit (the one with the FT1300 rear diff support)
From the appearance of the FORE cover I can't use your FT1401 :cryying:, sure looks like a nice part though. :thumbsup:
 

ac427cobra

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.

BTW, looking at the second to last pic, is there any clearance room between the cover and rear support bushing? Appears they are touching?

That photo may be somewhat deceiving. There is a minimum of 1/8" of an inch clearance everywhere.

I ordered your kit back in the spring of 09 did you have the 5001 kit then?

We've only been doing the FT 5001 kits for less than a year. Before that we had the rear lowering diff mount but it was not compatible with the Ford Racing diff cover because it had not come out yet. The part number for the Delrin isolated rear diff lowering mount at that time was FT 1400.

Hope that answers your question.

:thumbsup::coolman::beer:
 

ac427cobra

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Hi Bruce!

I have the FORE Billet Diff Cover. Haven't tried to install it yet.
Will I have any problems using it with your bushing kit.
I have the complete FT5000 kit (the one with the FT1300 rear diff support)
From the appearance of the FORE cover I can't use your FT1401 :cryying:, sure looks like a nice part though. :thumbsup:

If you have the FT 5000 bushing kit, your Fore cover will fit with no problem. If you don't have a driveline vibe you should not have any concern regarding the lowering rear diff mount.

However.... IF you have a Fore cover AND you want to run a rear diff lowering mount you are going to need to do extensive milling on the cover AND on the rear lowering bracket to get them to all fit together.

Here's only part of the milling required on the Fore cover:

foremilling.jpg


Here is the milling required on our Delrin isolated rear diff lowering mount:

forerearbracket.jpg


BTW, there is additional milling required to get the assembled parts to fit in the subframe but I unfortunately did not get photos of that.

FWIW

:thumbsup::coolman::beer:
 

*SVT*

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Thanks for taking the time to call and talk with me. I'm one of the lucky 4 getting one of these and the FT5001 kit.
 

ac427cobra

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Very nice Bruce. I should be paying for those 2 kits this weekend or Monday at the latest. But these two guys opted to stick with their current setup(IRS Brace) for now.

BTW, looking at the second to last pic, is there any clearance room between the cover and rear support bushing? Appears they are touching?

Here is a photo I took today at the shop to show the clearance of the Delrin isolated rear diff lowering bracket to the Ford Racing cover:

FT%201401%20on%20Cover.jpg


:thumbsup::coolman::beer:
 

ac427cobra

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I'm in for the next round of covers and bracket combo

The good news is our Delrin isolated rear diff lowering mounts already fit the Ford Racing cover.

The bad news is the Ford Racing covers are on back order with expected delivery being at the end of January.

We will continue to take orders on a first come, first served basis.


:thumbsup::coolman::beer:
 

N/Angel

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Is it possible to upgrade from FT5000 to FT5001 with your milled cover without lowering/removing the IRS out of the car?
or is there a way to get exact measurements on where/how to mill the cover I have sitting here?
 

ac427cobra

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Is it possible to upgrade from FT5000 to FT5001 with your milled cover without lowering/removing the IRS out of the car?
or is there a way to get exact measurements on where/how to mill the cover I have sitting here?

The basic differences between the FT 5000 and the FT 5001 is the FT 5001 kit contains our Delrin isolated rear diff lowering mount. Changing the rear diff mount only requires removing the differential housing from the subframe. The subframe can say attached to the chassis.

:thumbsup::coolman::beer:
 

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