lone73

I bought a kit from a guy in BC Canada that adds upper control arms to the C3 rear IRS. He sent a copy of a Corvette Fever article that spoke very highly of the setup as tested on a '79 vette. Looks like it was originally designed and built by somebody named Giovanni <sp> with VERY good track results. This kit totally eliminates the halfshafts from acting as a suspension component reducing differential, stub axle,tire and u-joint stress and wear. The really big advantage though is in handling improvement. :cool:

The original designer built these for a while sometime around 1990 and, I assume, had a detailed setup procedure on how to get the most out of it on the track. If anybody has any info on this I would appreciate it. I would like all the expert info I can get on how to adjust it.

I would also like to get the original mag article on it if someone can tell me the month/year.

PS
If anyones interested, a Street & Performance MPFI "tunnel ram" intake WILL fit under a '73 up Cowl induction hood. Looks pretty cool too. Looking at it in their brochure gives the impression that its too tall. Fits on my car with about 3/8" clearance under the hood.
F/I conversion is slowly progressing. Mine is not a kit but rather a piece-meal conglomeration with DFI computer and Ford 24# injectors. The car is running but I wanted to get this suspension mod on it before reinstalling the exhaust.


thanks
dr

Lohkay

I'm very interested in your rear suspension kit...I always found the corvette IRS to be flimsy and any idea would be welcomed. Do you know where someone could buy this kit?

71roadster

Yes, please tell us all more. What does the kit consist of? Can you scan and post the article? Where did you buy the kit? And if you're not shy, how much $$$ ???

lone73

Lokhay, 71 roadster:

The kit is chrome molly <sp?> upper control arms with Heim jointed ends and the 3 aluminum attaching brackets plus one below the diff to lower the attachment point of the lower control arms. Cost me $330 plus shipping. I had him throw in a set of used VB smart struts for $100 extra.
The guy is in Penticton BC Canada and makes them in his garage. Stingy74 has some very good pics of his install he has sent me. He may be able to post them here. I could snail mail the article if someone wants to post it.
dr

Chuck Harmon

David,

I know I have the original article stored. I will try to find it and e mail it to you. It is a great design. One of the best features as you have said is unloading the half shafts from the side to side forces in the stock setup. The other is making the lower control arm parallel to the half shaft and the new upper control arms. The wheel remains virtually perpendicular to the ground throughout its arc of travel. I think this is what made for the greatest amount of handling improvement.
Chuck

As I recall, the upper bracket mounts need to be welded to the top of the differential at the one end and welded to the trailing arm at the other. A very trick looking setup when done!

Chuck

BubbaJJ

This is cool, kinda like it shoulda been designed in the first place. Post whatever info you all can come up with, sounds like a mod every C3 should have.

Stingy74

Here is what the setup looks like installed on my car. I have posted these pictures before but I sure everybody didn't get to see them.

This is a shot of how the upper arms connect to the differential cover.


This is a shot of how the arms connect to the top of the trailing arm via the heim end joints.


Here's a shot of the complete install. Look, there's the upper arms! Very trick!


Here's what this kit eliminates!! Yah, I think there's camber change happening here!

lone73

Thanks Chuck,

The original design did weld on according to the article I think. This version is all bolt on. No welding required.

dr

74vetteman

I would be very interested in getting that fellows name, phone number, and address in BC. I have looked at Tom's Differentials 6 link setup and don't like the way it is welded to the differential carrier. It would mean taking off my Vette Brakes adjustable dual mount spring.

NHRA rules call for all IRS cars to have a six link setup if you run better than 12's, meaning any C3 would have to be modified.
One advantage that Tom's differentials kit has is a mount for half shaft loops (same as drive shaft loops) which is also a requirement for running under 12 seconds. I guess that maybe one could fabricate a loop that would attach to the diff carrier.

71roadster

That is a very interesting setup. I wonder tho if elimating camber change means that the half shaft yoke needs to be able to slide (if only a little bit) within the rear housing. Do you have to remove the C clips that keep the half shaft in place in the rear end? Stingy 74, did you check the full swing of the installation without the leaf spring attached to check for binding anywhere?

I too am interested in some contact info. Please post. Also, whomever has the e version of the article could you please post it or mail it to me at ccherri@yahoo.com.

Thanks,
Chris

Stingy74

71Roadster

Since there is basically no camber change the stub axles don't move anymore which means the c-clips do get removed. In the scheme of things I guess it means they won't be floating around in the gear oil anymore!! Some people suggest you shorten the stubs to the point where the clips are retained. This allows for further toe adjustment, but I left mine at stock length with no problems. Interesting you should talk about the assembly prior to the spring install. I didn't check but was also not worried because a friend had at the time just finished the same install on his 76 with the same spring/shock setup. He never encountered any problems and neither did I in the year mine had been in service. The only problem I had was a wheel rubbing situation which is my own fault really. I lowered my car with 10" end bolts which brought the end of the spring very very close to my 5" backspace wheels. I did minor damage to the inner lip of the wheel. How does this tie in with the 6 link? Well, the kit is designed to eliminate camber change so I immediatly reduced my 1.5 degrees of negetive camber to near zero. I didn't realize that I had just brought the bottom of the wheel closer to the end of the spring. So I did what I didn't want to do and set it up at 1 degree negetive. Made me feel silly since it's totally against what the kit does. That means I have 1 degree negetive at the top and bottom of my suspension travel. Not exactly what I wanted, but it still works well. Actully, the guy who makes the kit was recently at an event our club hosted up here in Saskatchewan. He actully suggested 1.5 degrees negetive!! He went on so say that you'd get a better roll on the tire but my master plan was to have 0 degrees for maximum traction at the drag strip and i'm still going to acheive that when I order my custom shortened spring from Vette brakes.

SteveG75

Can anybody post or send me contact info for this setup?

Since I plan on rebuilding my suspension this summer anyway, this would be great. Sounds like a real bargain at $330 (CDN?).

Thanks.

ZD75blue

for 330 what ever I would by that kit because toms diffs kit is what 2,000 dollars and its a 4 link

Does the fellow have a website?

ZD

Frank75

David/Chuck:

Please try to post the article somewhere or let us know if you'd be willing to email. This sounds like a wonderful upgrade. I'm assuming that contact info is in the article?

thanks

MikeC

I'd love to take a look at the article and get some info on the setup.

Mike

stinky

DavidR-as with several others here, would you please provide some contact info for the supplier. The only link systems I've seen are those by Tom's Diff and that offered by Guldstrand.com/5bar.htm (very different setup), but both of them are pricey. My only real question is does it work and work well? Thanks

stinky

Chuck - could you either post the article's location or email to me as well. Thanks

PatsLs1vette

im also very interested in the setup ive been thinking of making up my own brackets and adjustable rods and doing it myself....any pics would be helpful.

lone73

I bought the upper arms from an individual not a business and was hesitant to post someone elses personal info on the net. I just called him and got his permission to do so.

His name is Rick Taylor, Phone # 250-770-1965

I have been tinkering with my scanner trying to get my copy of the article scanned and sent to somebody to post. In order to get readable scans the resolution required is such that the file for one page is 128Meg. There is probably a better way to do it and keep it reasonably sized, I'm not a computer nerd by any means. I'll snail mail it to anyone who would like to try.

later
dr

Chuck Harmon

Hope this comes through ok. My first picture post. I used a block of aluminum for a spacer under the differential to make my lower control arms parallel to the half shafts. The no side load on the half shafts is a great arrangement, but my camber change is all but gone too. The cost was very minimal. My idea won't work as well if you are running pipes under the car. My sidepipes avoided this clearance problem.

Chuck


Lohkay,

Nice x's huh? I hope a ricer blows your doors off tonight! :smash:





[Modified by Chuck Harmon, 3:12 PM 9/10/2001]