My question is can it be done? I just found a heck of a deal on a C5 IRS rear assembly - minus the tranny/differential and axles. Obviously this would require an insane amount of planning and work, but do you guys think it is possible? Anybody have the measurements for the C5 rear? Besides the measuring and re-mearsuring, and custom mounting points, what else might pose a problem? Thanks.

its def doable, someone has pictures of it done from some corvette. IF you can weld and are good with measurements then you should be able to attempt it. I think you will have to cut the floor out where the gas tank is and then built a frame for the rear end and then weld that to the car . It would be cool . Buy it and go for it.
i had fun when doing the chrysler rear end in my trans am .

Do you know where I can get ahold of those pictures? They would definitely help.

I've never heard of the C5 IRS suspension in a thirdgen, however there have been numerous posts of the C4 IRS suspension in a thirdgen. If you start from there, you may find some links to the C5 stuff.

To get around the problem of having less than 3 letters in a post when you use C4 or C5 in the search, put an asertisk (*) behind the 2 letter work. eg. "C5* IRS".

I don't think your going to fit a C5 IRS in a thirdgen because the transmission would probably cause a huge clearance problem. C5’s are transaxles with the transmission in the rear.

Having a rear mounted transmission in a camaro is the whole coolness factor of this suspension swap. I'm 98% sure that the transmission won't clear. This isn't that big of a deal compared to actually mounting the rear assmebly. The worst would be that I'd have to removed the back seats and enlarge the tunnel.

My main concern is the length of the torque tube. Any body know the length of the thing? If it's too long do you think I could get it shortened?

The other concern I have is the size of the rear wheels. They run 18s on the vette. Is this because they have to or just because they want to? I don't really like 18s on 3rd gen camaros - i think they're too big. 17s are perfect.

This is why I'm worried about wheel size - see how tall the knuckles are?

They run 17's on the front, and the spindles are the same ones used on the rear.

http://www.badassride.com/images/Scr...s/Tyler_50-50/
is a 1st gen camaro with a c5 suspension stuffed under it. You might have to relocate the gas tank. since you're not going to have a back seat anyway, you might as well use the Corvette tanks.

The torque tube and propshaft both appear to be aluminum, but if you have to change the length of them, you have to get the alignment perfect. The propshaft is supported by bearings in the torque tube, and any misalingment will tear the bearings up.

Thanks for the link and the info. Those pictures will definitely be useful. I just wish that he had some captions or something.

I figured I probalby would have to move the gas tank. Using a vette tank is a good idea. I'm not sure if that's what I want to do though. Maybe.

For the torque tube, the outer tube is definitely aluminum. However, the inner shaft, I do believe, is steel. This is where I have the most concern of getting the tube shorten if necessary. Do you think a shop would be able to machine down the inner shaft? I'm not talking about cutting a chunk out and welding it back up - that is a big no-no.

Here's some shots of the corvette torque tube from... http://97vette.com/events/Museum2002/

http://97vette.com/events/Museum2002/dscf1143.jpg
http://97vette.com/events/Museum2002/dscf1144.jpg

Thanks for the pictures. I'd never seen the guts of the torque tube before. I get it now. Thanks.

yes it can and has been done.

Not my car.. just once I got a link for.

http://www.quarter-mile.net/IROC_index.htm

click on the individual pic's for info/pic's of them mods.

That's a C4 rear, not a C5

dohhhh, my bad. i didnt even read the title. I just seen IRS in a 3rdGen. sorry..

the 18" wheels are not required. 17s work just fine, there are lots of C5s road racing with 17" rears due to lack of 18" race tires.

Good luck, this would be badass.

That green 1st gen is my car. I can answer any questions you have about the tube chassis and the C5 stuff on it.
Tyler

Anything is possible, but I think installing the C5 IRS would be way more trouble that what its worth.

What are you going to do for a bellhousing? How are you going to mount the torque tube to the back of a gen 1 small block? How are you going to support the back of the engine with the trans mount missing? How are you going to fit the IRS under the car? Mount it to the car?


There are a host of problems that you will face, none of them will be easy or cheap to overcome. You would be better off, if you are really set on an IRS, looking into a C4 IRS. Or even a 99-up Mustang Cobra IRS. The Cobra IRS is modular. It has it's own frame, and all the control arm mounting points are based off that. It's completey self contained, and can be installed into any car with only 4 mounting points. Unlike the corvette IRS, which has a 4 link setup requiring 8 (or possibly 10) different mounting points.

Holy blerting schnit, that car is ****ing sick

Would an independent rear in a 3rd Gen hold up under Race conditions?
True racing that is, the kind where you turn the wheel left AND right.
I ask because the mounting locations do not seem to line up with the stonger areas of the unit body.

What's the going rate for an C4 IRS???

It's sick alright...I watched it get toasted by a plain IROC with a 383 and a TH700R4 at Indy Raceway Park back in June.

Sorry for resurrecting this thread but the quarter mile page is dead, does anyone have the pics of the car w/ the C4 IRS? I have a couple of C4 Dana 44s and some C3 Dana 44s lying around, might make a nice project

no one has these pics?

I do....But they are on my external HD, which it out on loan right now so....

To the best of my memory about it...The C4 was the easiest/best fit.

The C4 and C3 differentials don't differ a lot in size, in fact the C4 D44 is even larger. The C3 one has a pinion mount, the C4 is set up for a c beam.

This is a C4 Dana44 in my 82 vette w/ custom built double a arm coil over irs





Granted, the C4 Dana44 is a whole lot stronger than the C3 one (C3 one has a poor support for the caps, caps are also cast and mating surface between cap and case is not machined but as cast too) but when properly built it should handle reasonable power without many issues. If you check out some of boyds old rods, he liked to use these. The 80-82 C3 Dana44 is easily recognized by the pinion mount, all earlier diffs are either eaton or auburn (very early) cast iron units. The cast iron units are stronger than the 80-82 unit and even bolt up to the aluminum batwing, so you can run one of those too if desired. There's even a 12 bolt upgrade for those, making it near bulletproof for most anything.

C4 (left) and C3 D44

C3 D44


C4 D44


This is a sort of copy of the C4 system that I built years ago, using the 82 Dana44. Similar idea with 2 forward links (dogbones in the C4). It was built using stock C3 (steel) hubs, would be even easier with C4 hubs, all you'd need is the forward rods and
drill and tap the batwing for a mounting plate for the camber control pivot in the center (easily done, there are already bosses in the batwing, I ahve adapted a toe control setup to one before, it drills and taps for M12 bolts easily, the pic of the diff/batwing has the 4 M12 allen heads in it already)



I should have better pics showing the entire thing but I think it's quite clear how it works like the C4 stuff.

The C3 D44 w/ batwing & M12 allen bolts for toe control center pivot



The length of these forward rods can easily be changed, what matters most is the virtual swing arm these 2 make, with their intersection point being the instantaneous center, determining anti squat characteristics as well as hub yaw and some other things. Shorter links are a disadvantage but it beats cutting up the floor. I'm not sure how much too long the stock C4 dog bones are but I wouldn't mind shortening them a bit (using adjsutable rods like these above)

using a C4 diff requires fabrication of a pinion mount, or you could use the C beam pad to fix it rigidly to the transmission tailshaft, this is how the C4 beam also works.

This is a pinion mount I built for my 82, the pump is a single stage scavenge section for the rear end cooler.





It hangs off a poly bushing (easily shimmed for pinion angle)


Both the C4 Dana 44 and the 80, 81 manual and 82 automatic diff use 1350 U joints on the halfshafts and 1310s on the pinion yoke..

Another difference is a slightly larger width on the 80-82 batwing, it's exactly 2cm wider than the C4 unit.

So, apart from a C4 unit, one could use an earlier eaton diff (cast iron) which has 12 bolt upgrades available, many gear sets available and it has a pinion mount, or use a C3 8-82 D44. Another possibility would be the Viper SuperDana44 which is the same internally as the C4 unit, the case is jsut a biyt meatier and has a set of forward mounting ears.

Why not try using the rear suspension out of a vehicle that has its own complete rear subframe?

Would make it so all you need to do is fabricate bracketry to hold it into the car.

Something like a Nissan Skyline or Nissan Silvia Subframe:



Just have to fabricate the brackets, since their near the same width as a thirdgen rear end.

Pumpkin bolts into the middle, and then its pretty straight forward from there.

5 x 114.3 blot pattern isnt far off a 5 x 4.75"

What about GTO or G8 rearends? They are on subframes, and the G8 subframe is held in by 4 mounting bosses. Not too sure on their width though, may be a bit too wide

I've wondered this for quite some time now. Now while the GTO diff is weak, they do have the 8.8 upgrade for it which would be plenty for most of us. Two others to look at would the the thunderbird and jaguar setups. All of them can be had for around 300 (and all 3 mount the same...4 bolt cradle).