sahlomonic

Does anyone know of anyone who's put a Corvette IRS into a 3rd gen? What are the pro's and con's of it? Would it be worth doing if you found one at a junkyard?

MRZ28HO

It wouldn't be worth it for a street car, unless you do it for bragging rights only. The rear suspension on F-bodies are very good, so much so that GM did not change it when they went to the 4th gen. Parts interchange from 1982-2002. If you are a serious road racer, that needs every little edge and rules allow for such, then yes it's do-able. Be forwarned, it is a cost consuming project. You will need to reinforce the subframe of the F-body to support the extra loads imposed by an IRS (which it was not designed to support). Plus you are increasing the chances of being out of alignment, since now you must worry about the rear wheels as well as the fronts.

86 IROC

It is possible, it has been done. There was a car in the Car Craft shoot out one year - 88' GTA I think. It had a 6 speed swap & a Vette IRS IIRC. If I had to guess... I would say the article was done in the early 90's. Good luck finding it.

badassT/A

Believe it or not, I think someone is in the process of this on www.thirdgen.org Do a search there and you will probably come accross it. Here's a generic link that doesn't show much at all http://www.rareautodesign.com/ManIRS.htm You may want to edit the link and go their home page to get more info.

dnovotny

I've been looking into this mod for a long time, so I've tracked down many leads and finally got a "real/helpfull" scoop. First, rare auto design, probably real that an IRS was installed, but its a "one-off" and the place that did it has no interest telling you or I how. Second, many people come out of the woodwork claiming to be working on a kit. Don't believe this either, nothing's ever come from it, never seen any pictures or real progress. Last, there are one or two sites that make custom IRS setups for Cobra's and Mustangs. This was and is a real possibility, but too many hoops to clear to make it fit.

So, for the scoop. Within the last year, someone posted about his brother installing a C4 IRS on his 3rd gen. Definitely real. So, I recently contacted his brother, and asked lots of questions, also he sent me lots of photos of the setup. Attachment points: no significant reinforcement was needed since the dog bones attach right beside the lower control arm frame mounts (I believe they added a reinforcement plate under the carpet), the IRS hanger is attached where the panhard rod brackets are, the stock shock location is re-used. Only part that looked less than ideal is the axle-to-transmission attachment, which I hope to improve on. Cost: 5K for parts/labor.

How well does it work. Well, they own the 3rd gen, and a C4 to boot, apparently it handles as well as the C4. No squeeks/rattles/problems to report.

As for myself, I have two '91 T/A 3rd gens (one I'm trying to sell if anyone's interested), and an '01 T/A. I'll be installing a Dana44 C4 IRS soon on my '01, probably use the same shop, but I won't be able to drop off the car until spring (when the snow melts). My '91 GTA will retain the stock setup, but be modded similar to my '91 T/A which has amazing handling.

Later, Dave