Anyone out there done the C4 rear suspension conversion on they're 69 Camaro??? I'de like to know how it went. I'm going to do it on mine soon. Chime in.

Thanks,
Dave

Here is a 67 that has C4 rear suspension.
http://www.angelfire.com/il/cormaro/

I'm not trying to tell you what to do, but...

The C4 rear is aweful. There are much better alternatives out there, and a solid axle is one of them w/ a 3-link or a triangulated 4-bar.

what is so "aweful" about the Corvette rear suspension?
isn't it one of the best engineered oem setups on the planet?

I dunno about the C4 being the best "OEM" engineered setups, but IMO, it's one of the worst IRS units out there. Now, the C5 is a different story.

Huge camber issues through the bump curve, enough to only allow less than two inches of bump travel, that's it. While it is light weight, it can only handle about 350HP reliably. Also, they are increadibly hard to modify the width.

IMO, if you want IRS, go with a Mustang Cobra setup or something (I don't know much about those, but they appear to be good). Other than that, a 3-link on a solid axle would be the way to go. It just doesn't have the BLING factor.

Too much camber change is a problem with C3 and C4 rear suspensions. I believe Guldstrand sells some parts to help this problem. I hear the C4 is an inch or so too wide for a Camaro, don't know what they do to get them to fit, probably they do it with wheel offsets.

A solid rear axle isn't a bad alternative for a Camaro, just not as impressive.

The 1984 through 1987 is the right width for the rear end of a camaro. The Dana 44 can handle the 400 hp. I like the idea of having independant rear suspension for cornering and handling reasons. Plus I do like to be different. I don't see the c5 as working at all. Transmission in the rear system isn't for me.

Please look at TSM's set-up if you want a strong IRS!!

http://www.tsmmfg.com/

It's based off the 9" and to me is good value.....

pdq67

Paul, I don't see a rear suspension on that page. ???

David,

I don't know what's going on, but I have onna their old 1989 cats, (or thereabouts), that list's an 8" and 9" IRS!

Please contact them and ask if they still sell it??

pdq67

I dunno about the C4 being the best "OEM" engineered setups, but IMO, it's one of the worst IRS units out there. Now, the C5 is a different story.


I beg to differ. I have a C3. That is by far the worst engineered IRS setup. But, very good for its time. ;) The halfshafts support a lot of the wheel weight, and have terrible camber issues. I think the C4 Corvette IRS is a great setup. It's not perfect, but it can be easily improved. Plus, they can usually be found for about a 1/3 of what one of these aftermarket IRS setups would cost! If you're going for an all out autocross car, a C4 setup might not be ideal, but if it's a daily/weekend driver with spirited driving or occasional track use, I think it's probably the best bet. Unique Performance has an interesting rear coilover setup that you should check out, if you can drop $5K on your rearend that is...

The effectiveness of the C3 is often lumped with the C4. C4 really isn't that much better than C3, honestly. They aren't easy to change either, you'd often have to rebuild the entire thing and make your own brackets.

And I disagree about it being the "best bet" for a daily driver. If that's the case, the Cobra IRS would be better IMO. It doesn't have as much anti-squat as I'd like to see, but the camber curve is much better.

For me, if I absolutely had to do an IRS, it would be C5 the way, no question. Otherwise, solid axles work great!

When I said best bet, I'm also throwing cost into the mix. I would assume that the IRS setup from a C4 would be much cheaper then that from a Cobra. No doubt a Cobra IRS will outperform the C4 IRS in just about every way. If a person considering the C4 IRS swap had fabrication/welding skills (Which they should when attempting this!) they could turn the C4 setup into an affordable and well performing setup. I do agree that the C5 is lightyears ahead of just about all IRS setups out there, but, my opinions are biased, I love Corvettes. ;) Also, the 2nd generation RX7's have a really good IRS setup. Silver, I see you're from Renton... I used to live in Renton/Fairwood, before moving to Federal Way. Washington is home, Texas is where the Air Force put me. ;)

Gotcha! I just now moved to Auburn.

Cost involved, I agree it's probably the best setup to use. They're widely available nowdays.

Wayne Due makes a bracket kit for installing C4 IRS into first gen Camaros.
http://www.waynedue.com/

Mike

David,

Were you able to get any info out of TSM about their IRS unit they have made that is based on the 8" and 9" rearend center sections??

pdq67

I'm trying top contact Wayne Due and there's no answer??? Left an e-mail also and no responce??? What's up with that???

David,

Were you able to get any info out of TSM about their IRS unit they have made that is based on the 8" and 9" rearend center sections??

pdq67

pdq67,
Nope, I'm not really interested in what they have, and I'm too buisy, - but if you would like to follow up on it, please post the info back here.

Maybe Wayne's on vacation? He's a good guy, don't worry about it.

He can be tough to catch sometimes. I never have had any luck emailing him. Just keep calling and you will eventually catch him.

Mike

Got a hold of Due. Ordered the IRS SYSTEM and received it. Had the C4 rear powder coated and built with a 354 gear. Looks fantastic! Stay tuned for the install.....

it can only handle about 350HP reliably.

Where exactly are you getting this from, now of corse it depends on your definition of reliable. http://forums.corvetteforum.com/showthread.php?t=1326283&highlight=dana+44+power&forum_id=48

Given where the dog bones mount it would be real tough to run anything more than a 285 tire, as well as it probably being a low profile tire since anyone doing this conversion is looking for handling, id say most people are very very safe with a undammaged dana 44 due to the lack of traction with any really high power setups.

Also you are certainly right about the c5 being a superior setup, and they can be set up as a rear end not only a transaxle. 21st century street machines does build a setup, however given the extremely close tolerences they will only install their kits and at the end of the day about 10k to have it in the car, not to mention the unit itself... http://www.21stcenturystreetmachines.com/

Now i am doing the swap myself and the biggest reason for it was price. I was planning on the dse quadra link, moser 12 bolt and new baers.
quadra link-$2100
12 bolt -$1800
brakes- $900
so roughly $4800 without install and misc parts needed

For the d44 irs,
dana 44 irs-$1800
Coilpvers-$400
Wayne due irs install kit-$700
now im installing it myself so for about $3k having a complete irs setup.

It may not be perfect but its got more than enough for my car at the moment, and its extremely upgradeable as every vette made for over a decade had them.

Does any one know if there is a bolt on coil over 4 link like the one air ride has. and does anyone know how the bolt on 4 link from air ride performs at the track while drag racing?

Where exactly are you getting this from, now of corse it depends on your definition of reliable. http://forums.corvetteforum.com/showthread.php?t=1326283&highlight=dana+44+power&forum_id=48

I'm talking about street tires, not drag. Once you throw slicks into the mix for street suspensions, all bets are off! We used to carry the C4 IRS and I've dealt with so many I care not to think about it. We ended up dropping it due to the complications.

I know there are people out there who will say "Well I know a guy who's putting out 2000HP through is C4 IRS and it's fine." It all depends on on the resistive force between the tire and the ground and the guy who's modulating the pedal.

Sorry I haven't posted in a while. The C4 rear install went surprisingly well. Measure 5 times, weld once is the motto. This was my first time and it went very well. Wayne Due was a great help and without tubbing the car I have 11 inch low-pro tires on 18 inch rims. The stance is great! The install is definatetly doable at home!

That sounds good! What size tire did you stuff in there?