IRS in a 66

I personally believe a multi-link or torque-arm rear suspension would work just as well if not better. My '99 Cobra was plagued with wheel-hop even after switching to DA Koni's, aftermarket bushings, and heavier springs. Essentially, you would be trading one set of problems with another.

trading one problem for another? I understand that...I have a wife. I don't need another. by the way with Irs you also reduce the unsprung weight {the car thinks that the wheel is lighter}

Marshall from here used a Jaguar IRS on his 66 stang... pretty sweet setup considering it had inboard disc brakes. OTher than DVS, not much info out there

there is a web site out there that someone has that re-creates the factory '66 irs just search more!

usedtobe 67p51d said:

trading one problem for another? I understand that...I have a wife. I don't need another. by the way with Irs you also reduce the unsprung weight {the car thinks that the wheel is lighter}

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Agreed. Hence the problem with wheel hop. The IRS did provide a civilized ride on the streets and was much more stable in bumpy corners than the live axle. Overall weight is considerably more however, around 80 pounds. That's roughly half a tenth in the 1/4.

If you are running a high horsepower and more of a straight line pilot, keep the live axle. If you like the twisties and are more of a road-racer type then consider the IRS. All said and done, it would only be marginally better on the track than a well set up solid axle.

$.02

DVS is still working on adapting the latemodel Cobra IRS to the early (65-66) cars. The later cars are bigger so everything fits within the stock sheetmetal with little hacking. Interestingly, some Toyota Supra stuff actually fits.

I have seen a website discussing a very early IRS system built by Shelby/Ford around the time that the GT 350 was developed. As far as I know, this is complete unobtainium. The parts just don't seem to exist, and no cars are know to exist with the setup installed. I also can't find the site now. My thoughts are that it may have been developed but probably was scapped due to cost. Plus, Shelby was beating everyone with the stock style setup anyway.

A better, easier alternative would be to adapt a trailing arm/coilover setup with a panhard bar. This would be a great improvement over the stock style leafs. The downside is this may be illegal in most of the vintage racing series.

In the latest issue of Mustangs and Fords, there is a 66 fastback that a father and daughter built using a irs from a 99 cobra and 03 cobra engine. The artical said the father had the rear frame section of the 99 cobra welded into the 66. It also has the mustang II front suspension to fit the fat 4.6 in there. Very nice car, done in the black and gold of the hertz rental car. There was also a better write up and pictures in the june 2004 issue of super rod magazine. They didn't say if they had to modify the sheet metal but looking at the pictures it appears that the tire is slightly out side of the fender. I think the car may of also been in a popular hotrodding magazine a couple of issues ago also.