C4 Rear suspension.

[Bow tie downunder]

I have a 57 convertible and I could not mount the stabiliser to the top of the suspension as it interferes with the body mount and I did not like the forward bottom mount position. I have made some spacers and would like to use it in the bottom of the original position.
The bar itself will be about 1 1/2 inches longer. I have made a bar out of PVC pipe and everything clears. Not sure of mechanical dynamics in this position. Any input appreciated. Thanks, Mick

[NickP]

With the weight of the car on the suspension, what is the position of the horizontal arms of the bar? Longer means less also so considter tube size and wall thickness.

[chevynut]

Hi Mick,

We built a C4 frame for a convertible and ran into the same problem. I discussed it with the builder and we decided the easiest solution would be to move the body mount to the inboard side of the frame. However, it looks like your frame is already painted.

Is your swaybar mounted above or below the frame? It looks like it's above it. Some people have tried to mount it below the frame but that causes it's own problems.

A swaybar will work the same whether you're pushing or pulling on the arm. The only issue I see with your design is that the bottom of the link will move fore and aft a lot with suspension travel. You have a large angle on the arm from the pivot point to the link attachment. As the suspension compresses, the link will move forward and as it extends, it will move aft. That will change the direction of the loads on the link mounting bracket so you need to make sure it's strong enough to support them. If it was me I'd probably make the link longer and the spacers shorter. I typically get about 2" up and 2" down travel on my suspensions which is plenty. Since I don't know your arm length and angle I can't tell how much your link will move.

Your installation looks good. Got any more pics of your chassis?

[Bow tie downunder]

Thanks for the advice. I can't make the spacers any shorter as it interferes with the knuckle brace. The stabiliser
bar arm is 10 3/4 inch and 4 3/8 and the angle is approx 45 degrees and will be solid. Probably 1 inch.

[Bow tie downunder]

More photos. Also it's a Chevy Citation steering rack.

[chevynut]

More photos. Also it's a Chevy Citation steering rack.

Looks good Mick. In fact it looks a lot like my C4 conversions right down to the LS mounts .

I was wondering why you used the Citation rack then it occurred to me that you must be building a RHD convertible. Cool. Is the rack the same length as the C4 rack at the pivots?

[chevynut]

Have you thought about using the spring bolt hole instead of the stock swaybar mounting location?

[Bow tie downunder]

The steering rack was extended about 1 1/2 inches each side .I thought of using the spring hole but decided it would not be strong enough .I will use the bottom original position as it has the angled web between the spacers .Chevynut advised me on setting up the suspension early in the frame construction I am gratefull for his help .Rick Roush Supplied templates for the front arms. Thanks for your help. Mick

[chevynut]

Mick, what ever happened to Rick Roush? He used to have a website with his C4 conversion but it's gone. I think it was the first one I ever saw.

I personally think the spring bolt hole is plenty strong. Heck, it holds up half the rear of the car.

[Bow tie downunder]

I think Rick Roush went into top end car sales then sold that business .His was the first c4 into a 57 frame that I saw .I had photos from that build ..'I had thought of the spacers and the spring hole with a link somewhere in the centre.Ill see how that looks .Have you thought of reinforcing the bottom coilover mount, Mick