Don't forget the bolt mismatch for the front bushings. The fox uses 12mm and new edge Cobras use 14mm. Maximum Motorsports has the proper bushing available.
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MKVIII IRS fit question.
- Thread starter 86GT2go
- Start date
There is a detailed post on here about the swap I will try to find it.
I found it, its under the suspension section, I just brought it back to life for you guys. 87_notch fox is the original poster, really detailed with lots of pics.
David
Active Member
Thanks
Read that post just a short time ago!
Trying to get back in touch with the guy who had the 03 IRS for sale, and am trying to get a salvage yard to come down on what they want for theirs (as it has been out of the car for 7 years and the car itself has been crushed for 6 years). Maximum Motorsports will be getting a call when I get the rear, and the lathe at work will be put to use making the bolt bushings (anti-crush sleeves) for the rear mounts (that have to be drilled through the trunk/frame). Still trying to locate a MKVIII that someone just wants gone (or will get rid of cheap.....under $1000)
Thanks for the discussion guys, it helps a LOT when it comes time to make the swap happen.
Trying to get back in touch with the guy who had the 03 IRS for sale, and am trying to get a salvage yard to come down on what they want for theirs (as it has been out of the car for 7 years and the car itself has been crushed for 6 years). Maximum Motorsports will be getting a call when I get the rear, and the lathe at work will be put to use making the bolt bushings (anti-crush sleeves) for the rear mounts (that have to be drilled through the trunk/frame). Still trying to locate a MKVIII that someone just wants gone (or will get rid of cheap.....under $1000)
Thanks for the discussion guys, it helps a LOT when it comes time to make the swap happen.
Been doing a lot of reading as of late. The only thing I will be taking (rear-wise) out of the Lincoln will be the carrier. It will get swapped for the Iron unit in the 99 Cobra unit I am hoping to get soon. Hope I can get the 03 unit instead, but so far the seller hasn't contacted me yet. If so, I will just keep the Lincoln unit for trade material.
Thank you sir I can't figure out how to copy and paste on this tablet.
More researching has led me to find that the 99 Cobra did in fact have the aluminum carrier as well. Looks like the big difference in the 03-04 units versus the 99-01 units is the control arms and the pinion cross brace of the 03-04. Considering the aftermarket has the pinion brace and rebuild kits for the earlier rears, I will more than likely take what I can get when it comes to Cobra IRS units and just part-out the Lincoln affair!
The hubs, half shafts and differential are all stronger on the 03/04. They changed the spline count to accept more torque. With that being said, the 99/01 is plenty strong enough to handle a Mark VIII engine with a few upgrades to stop wheel hop. Wheel hop is the big killer on the IRS units. MM or FTBR both have the parts to stop it. I was an MM dealer for years, but the FTBR kit has had better product development from my perspective.
FTBR? I will have to look into them, as I was going to grab the street-track kit from MM and the 03-04 pinion bar to upgrade the 99-01 unit. But if they make just as nice of parts, I will consider that option as well. Thank you. So the 03/04 units got the 31 spline while the 99-01 had the 28 spline (like the MKVIII)? Interesting. never broke a 28 spline solid axle at the splines, always at the neckdown before the flange. 28-spline would be great for my purposes!
The thing that causes the 28 spline to break is wheel hop. The pinion bar helps that more than a little. The best one we've used was the Kenny Brown piece. The bushing set from FTBR will take care a bunch of it as well. Don't get me wrong. We install a lot of MM stuff too. They make good stuff. On the street, MM, Kenny Brown and FTBR are all good.
Was reading up on FTBR stuff, including their own page. Looks like I have two very good options when it comes time to do some IRS work. I also came to a few conclusions on my own while reading/studying the merits/workings of the IRS. I am glad that I posed the fit question to begin with, and even though the Lincoln unit was found to not fit the Fox, it did bring up some good info and sources for parts/tech on the IRS set-up!
Depending on what your budget it, you might like to visit Kenny Brown Performance.
http://store.kennybrown.com/category/catalog/99-04-cobra-irs/suspension
The front torque brace (aka dif cross brace) is top notch. I may eventually go to his IRS control arms as well on my vert, but they are a bit pricey. What I don't like about them is that they require coilovers.
http://store.kennybrown.com/category/catalog/99-04-cobra-irs/suspension
The front torque brace (aka dif cross brace) is top notch. I may eventually go to his IRS control arms as well on my vert, but they are a bit pricey. What I don't like about them is that they require coilovers.
- I was contemplating 4-corner coil-overs for a later date. Just to get everything mocked up/roughed in, I will be using conventional springs.
- At a later date, I myself may delve into making my own arms with revised geometry/pick-up points and front a-arms with Mathis-mod type relocation in the k-member. That way I can tuck the arm pick-up points in tighter/work more anti-dive in and get my control arm length right where I need/want it.
If you are considering modifying you geometry, you really need to talk to the guys ad Kenny Brown and FTBR. They have both experimented with the geometry of the IRS both on and off track. KBP used to offer a modification service for the IRS cradle. Finding one now is like hen's teeth...very expensive. FTBR equipped cars tend to beat MM cars on the track (wheel to wheel). There are those on Corner Carver that would disagree, but trophies are tough to argue with. I do occasionally see KBP IRS arms on ebay, but rarely. I'm a big fan of used parts when you can find them.
This entire car is being pieced together with used parts. It will eventually make it to having new/upgrade parts installed, but for the time being is a salvage-yard/Craigslist/Ebay/Forum classifieds build! I have started to document what I am doing to it (here and elsewhere) and will continue to do so as parts/time/money become available.
Be sure to keep a copy of your blog and info. Most of mine was lost. I used to own Atlantic Coast Mustang (acmustang.com). When we sold it, the new owner agreed to keep the forum and email live for five years. Both were gone in less than a year. When the server crashed, we found out that he had stopped backing up to save money. He did save some of the pictures. Here is one I like:
http://www.acmustang.com/gallery/main.php?g2_itemId=1038
That is Kenny Brown...and me leaning against his prototype car. We were a top ten dealer back in the day. The new guy doesn't even own a Mustang now...bummer.
http://www.acmustang.com/gallery/main.php?g2_itemId=1038
That is Kenny Brown...and me leaning against his prototype car. We were a top ten dealer back in the day. The new guy doesn't even own a Mustang now...bummer.
Being that I am too 'stupid' (my own words here, so I am not offended by anyone else who might agree!) for blog, I am sticking to a build thread-type format (for both places) and have the pics both on my computer and in an online photo-hosting site. Not much to report right now, as I just got the car everything will find its way into and it still needs some sheetmetal repair before I can really start even mocking the drivetrain/suspension up. I am still trying to find used parts reasonably priced and local to me (harder than it first appeared).
Nice pic you linked to, and sad to hear about the forum/site/new owners really not caring. To see something you invested so much time and care in destroyed can not be an easy thing. My dad had his own repair shop with customers (sometimes) on a waiting-list (when I was a kid). The local zoning board shut him down and even placed him in jail at one time. He finally said 'screw it', closed shop and moved us to Florida. A few short years later, the zoning board was disbanded by a popular-vote, but it was too late for dad. He was already getting established at the dealership he was working at, and had no intent of moving back to colder climates. Watching him lose what he started and seeing the hurt it inflicted on him only gives me a slight idea of what it must be like.
I will keep the build thread here going as I make 'progress', and will continue to learn from what has been done before and contributed to here (and elsewhere). Knowledge and guidance are two thing never to be taken lightly!
Nice pic you linked to, and sad to hear about the forum/site/new owners really not caring. To see something you invested so much time and care in destroyed can not be an easy thing. My dad had his own repair shop with customers (sometimes) on a waiting-list (when I was a kid). The local zoning board shut him down and even placed him in jail at one time. He finally said 'screw it', closed shop and moved us to Florida. A few short years later, the zoning board was disbanded by a popular-vote, but it was too late for dad. He was already getting established at the dealership he was working at, and had no intent of moving back to colder climates. Watching him lose what he started and seeing the hurt it inflicted on him only gives me a slight idea of what it must be like.
I will keep the build thread here going as I make 'progress', and will continue to learn from what has been done before and contributed to here (and elsewhere). Knowledge and guidance are two thing never to be taken lightly!
I will start again in about two years. Don't feel bad about your project taking a long time. The patience you are showing will see you through to the end. I gave up on my first few projects and now wish I hadn't. My last project was an 85 vert that I eventually finished and gave to my father in law. The current toy is an 86 vert and was a mess. I'm looking forward to watching your progress.