C4 suspension LCA mounting method change?

BBShark

Garage Monkey
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Had to refresh my memory of the C4 rear suspension. I think this is the stock LCA setup right?

008

Borrowing your picture, and hijacking my own thread here. I've been pondering shortening the strut rods to reduce the camber gain. My main concern at the moment is if it's an unwise move to modify an aluminum suspension component, and just go with steel tubing and Heim joints. I might entertain installing a Heim setup to dial in the handling, but that one non-engineer molecule in my brain likes the stock look of the aluminum struts. FWIW, I cut and narrowed the outer batwing area on my setup to fit inside the C3 frame with no problems seen, or any sleep lost, but active suspension components cause me a little more discomfort.

So, any comments/advice on the safety aspects of rewelding and gusseting the stock aluminum struts? Or should I just hope that the tube/Heim setup is lighter, and let the weight issue trump the appearance issue?

Thanks for any and all input.

I'm guessing these are adjusted with cams (like a C3)? I'm no expert on welding but aren't those forgings? Any issue with welding forgings? OK, I think I have reached my allotment of questions.

Oh, one more, what is the benefit of reducing camber gain?
 

phantomjock

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Oh, one more, what is the benefit of reducing camber gain?
Just a guess:
Make up for very soft springs?
Or, is there a steering issue?​
What is the current gain? How much do you want to reduce it?
Inquiring minds want to know.
Cheers - Jim
 

69427

The Artist formerly known as Turbo84
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.........................
I'm guessing these are adjusted with cams (like a C3)? I'm no expert on welding but aren't those forgings? Any issue with welding forgings? OK, I think I have reached my allotment of questions.

Oh, one more, what is the benefit of reducing camber gain?

First two questions, I am unqualified to answer.

Third question: If there's too much camber gain, there will be excess wear on the inner portions of the tire/tread. I currently have too much camber gain.

In addition to reducing tire wear, the reduction of (excess) camber gain should help cornering capability and stability. Also, during low speed acceleration or high speed deceleration, the reduction of excess camber gain should keep the tread flatter, resulting in better traction for both acceleration and rear wheel braking.

When I put this narrowed C4 suspension in years ago, I kept the strut rods the stock length (because of cutting/welding concerns), and positioned the inner pivot points such that the rear suspension would act like an SLA (Short/Long Arm) front suspension. It does that, but the fixed placement of the halfshafts does not allow a lot of geometry options. So, I need to shorten the camber strut rod.
 

69427

The Artist formerly known as Turbo84
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Oh, one more, what is the benefit of reducing camber gain?
Just a guess:
Make up for very soft springs?
Or, is there a steering issue?
What is the current gain? How much do you want to reduce it?
Inquiring minds want to know.
Cheers - Jim

I've bounced back and forth between the two '84 rear springs, neither of them known for being soft, but I haven't been able to package a rear sway bar with this suspension/frame combo, so all my rear roll stiffness is coming from the spring. Not ideal.

I've also gotten rid of most of the rear roll (under)steer built into C4 suspensions, so I want to make sure that I'm "maximizing" what rear traction I can get with the limited width tires that fit under my stock fenders.

I don't have any numbers on the camber gain. I just have observed that my tires are wearing unacceptably, and that it's too often a bit too "exciting" keeping the rear end going straight under hard braking.
 

rtj

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“ So, any comments/advice on the safety aspects of rewelding and gusseting the stock aluminum struts? Or should I just hope that the tube/Heim setup is lighter, and let the weight issue trump the appearance issue?”

You can buy chrome moly tubing kits with the heims, threaded inserts, and tubing. I’ve bought a few from S&W which were sold as engine limiter kits.

Or, buy some 6061 and machine some new ones.

After my experience welding cast aluminum, I’d say bad idea on safety related part. But, you’ve had good luck on the batwing.

Just a suggestion.
 
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