Fox Thunderbird Cobra IRS install

Topic: Fox Thunderbird Cobra IRS install (Read 2124 times) previous topic - next topic

Fox Thunderbird Cobra IRS install

May 13, 2018, 12:35:53 PM

I started an IRS install into my 87-88 Fox Thunderbird and shot some video of what hits and what doesn't. Obviously I'm not the first do do this but having done this on a fox mustang in the past the process is not the same for the Tbird. I also have not seen any pictures of how the IRS subframe interferes with the passenger fuel tank mount, but here is some video.

https://www.youtube.com/watch?v=Y265ePThnJA

Phil

Fox Thunderbird Cobra IRS install

Reply #1 – May 13, 2018, 09:55:45 PM

Before drilling any holes for the rear mounting brackets, you WILL need to lengthen the front mounting arms 3/4".

I don't have any pictures of the lengthening process but if you look close at the front arms, you can see the spacer I made.
I will take some pictures of a couple things I did to the re-useable parts from the control arms. Or check out some of the videos on full tilt boogie's website. They show a comparison between a stock bushed irs and an irs with their bushings. I didn't get their kit but I did take some of their tips and used them.

Fox Thunderbird Cobra IRS install

Reply #2 – May 16, 2018, 10:26:09 PM

I can place the irs anyplace I need in my car since I'm cutting the rear mounts off the subframe and if you look carefully the entire rear trunk is cut out of this car. Its just sitting there for the pictures. I may still lengthen the subframe as you did to better line up the spring.

Fox Thunderbird Cobra IRS install

Reply #3 – May 18, 2018, 11:13:45 PM

Here are a couple of pics I said I'd post

Fox Thunderbird Cobra IRS install

Reply #4 – May 18, 2018, 11:36:29 PM

Here's a good example of why you should lengthen the front mounting points, besides the spring, it puts the tire/wheels back in it's proper position in the wheel opening.

Fox Thunderbird Cobra IRS install

Reply #5 – May 19, 2018, 10:41:04 AM

amazing,,, so many smart people around on this board !!!

Fox Thunderbird Cobra IRS install

Reply #6 – May 19, 2018, 12:31:04 PM

I guess I dont my the position in the wheel well so much but if you wanted to use the 99-04 cobra rear anchor I dont like that you would need to cut it up. Mathis has a good thread on that floppy bracket over on corner carvers.

Fox Thunderbird Cobra IRS install

Reply #7 – May 20, 2018, 06:26:16 PM

I didn't have to cut up the rear mounting brackets at all. They fit very good as they are.

Fox Thunderbird Cobra IRS install

Reply #8 – May 26, 2018, 12:58:40 AM

Quote from: 1BadBird;465861

I didn't have to cut up the rear mounting brackets at all. They fit very good as they are.

Correct. But that is because you lengthened the subframe. If you choose not to lengthen it, you would need to modify the rear anchor bracket or the shock reinforcement.

Fox Thunderbird Cobra IRS install

Reply #9 – May 26, 2018, 08:11:55 AM

I am doing the very same thing right now, adding 3/4" to my IRS cradle arms to fit my '88 Bird properly (as I am also running it lowered with 18" wheels and need every bit of wheel well real estate acreage I can get!).

Fox Thunderbird Cobra IRS install

Reply #10 – May 26, 2018, 07:21:58 PM

Quote from: phils88gt;465922

Correct. But that is because you lengthened the subframe. If you choose not to lengthen it, you would need to modify the rear anchor bracket or the shock reinforcement.

That's true, I did have to make some spacers but I knew I would have to do the modification at some point because of how the tire looked.

Quote from: 88Boostedbird;465923

I am doing the very same thing right now, adding 3/4" to my IRS cradle arms to fit my '88 Bird properly (as I am also running it lowered with 18" wheels and need every bit of wheel well real estate acreage I can get!).

I believe I used your picture as an example as I couldn't get mine to upload.