IRS - pondering......

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Joined
Jan 9, 2015
Messages
584
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Location
Texas
My Car
'72 "mach" and a bunch of other stuff.
So pondering........

My car has gone through a rough life.  18 year old self went through a parking lot at way greater than parking lot speed and folded the car at the passenger window (Mach 1 fastback).

I drove it until the engine died and parked it in the garage.

About 10 yrs passed and I started working on it.  Frame shop got everything straight, but said it might do it again with the engine I was planning.  So we put Chris Alston sub frame connectors in it.  These are the cut the pan and weld them in units.  They did this, but in doing it they blocked the front leaf spring bolts.

Sooooo I have original springs in the car.  I plan on starting up again soon, selling my lighting to get funds.

Now you know why.......

So pondering.  How are the new mustang IRS's connected to the unibody?  Anyone heard of someone adapting to the 71-3 mustangs?

A while back I was looking at three link and moving the lower links inboard to the subframe connectors as they are 2x4 tubing.

As you can tell this will not be a concourse restoration, just me reliving high school hot rodding.....the car deserves it.

Thoughts?

Thanks,

RCA

 
Love it mate! I have looked at all the Chris Alston goodies and they look amazing.

That and the TCP stuff.

Sent from my iPhone using Tapatalk

 
Personally, (if you have the money) You cant go wrong with this set up.



its a schwartz performance G machine chassis. Its a bolt in full frame chassis built for 64-73 mustangs. It bolts in where the front and rear subframes bolt in and in a few other places. Some minor welding may be required along with removing the shock towers and welding in a flat panel.

They also offer Heidts IRS



you can see all the details here.... and price it out.

http://www.schwartzperformance.com/1964-1973-mustang-chassis-full-frame/

It has full Hotchkis type suspension and each wheel is adjustable.

They will build it to fit any engine transmission combination you want, including the coyote and 6 speed or T5.



upload full resolution photos



 
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Wow!

Cha ching!

I stopped adding upgrades at $25k

To rich for my blood.  Wish there was a kit to add a current mustang IRS in.  Might just need to start fab'ing.  

Hopefully they will be in wrecking yards for reasonable prices soon.

 
Rod and Custom makes a 4-link for around $1,700.

You might check this guy out, you'll have to contact him to see if he does one for our years. $8,500 for an IRS, if you have a 31spline 9 inch.

Possible donor vehicles include Explorers with IRS, SN95 Cobras and 2015, and up, Mustangs.

 
Rod and Custom makes a 4-link for around $1,700.

You might check this guy out, you'll have to contact him to see if he does one for our years. $8,500 for an IRS, if you have a 31spline 9 inch.

Possible donor vehicles include Explorers with IRS, SN95 Cobras and 2015, and up, Mustangs.
I have a Lincoln Versailles 9" in pieces.

How much torque can an 8.8 handle?

I see a lot of interesting kits for 8.8

 
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Hey to make your own frame it is only tubes and welds. Yes you have to find someone that can do the bends for you. You can also make some big gains by going up instead of down and add a 6 or 8 point roll cage which also adds to your life insurance. Look at how simple Shelby made the Cobra frames, huge round tubes. Rounds give you least weight to strength ratio, box gives you opportunity to give more up and down strength. A space frame is what you make it. An 8 point roll cage will shock you how strong the chassis then.

All the floor pan does is keep the water and dust out, well sometimes.

Just some food for thought. I worked in product and process design for many years. As a rule of thumb in a mfg. atmosphere it costs about $1.00 a lb. to mfg. weld and paint metal parts. So $500 lbs. cost $500 dollars out the door. I worked on reducing the weight of the John Deere combine harvester to allow increasing the size. When done it weighed less than the original and was 10 feet wider and was also stronger. Materials you select are a key factor. You can get yield strengths 4 times what was in these cars originally by using the latest UHSS of today and use same thickness.

A friend use to make quarter panels for Petty racing out of HSS so they held up better when they brushed the wall.

 
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Explorer 8.8 inch rear ends have a larger diameter pinion shaft than the 9" rears. They also have 31 spline axles, which actually make them stronger than the 9-inch/28 spline axles in our cars.

The older Thunderbirds and Cougars with 8.8-inch IRS have 28 spline axles.

Another interesting feature about the 2011 and up Explorers is that they are more of a unibody design and have a separate sub frame for the rear suspension.

 
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I have the 8.8 axle in my Bronco.  Its a 5000 lb truck and its 25 years old, still going strong with 250k miles.  SO I would say they are pretty tough.  Ford used to drop the 9" into broncos up until the mid 80's when they switched over to the 8.8.  The advantage being the pinion support.  The 9" has a pretty flimsy pinion support and is usually the failure point.  That can be avoided by getting a beefier aftermarket 3rd member like a strange nodular iron pro series 3rd member and if your axle assembly is in need up upgrading the Currie F9 is a very fine axle.  One of my buddies runs one in his bronco with a 408 stroker.







Beefy!







Save

Save

 
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All,

My lottery millions dream, would be to have a very very nice fab shop where you could take rotisserie attached mustangs, flip it over and design cost effective products for the 71- 73 mustangs. The chassis is very nice. Anybody got a cool $25K laying around?

mustang7173

 
I wish I had the coin to just go hog wild.

Thanks for all the info.

On the 9" the axles are held on by flanges on the bearings.  Are there "C" clips on the 8.8 or are they flange held, too?

 
I know for drag racing you have to have clip eliminators. How much of a deal is it for 5-600hp street?

351C C6 B&M 174 supercharger, also have a fogger system that was going to be staged injection when I bought it all 20 yrs ago.

 
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