C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Suspension question - Poly in trailing arms with Heim camber and toe rods - binding?

Old 12-03-2016, 12:18 PM
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Rob31
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Originally Posted by 69_427_SBC
Agreed on all points. I'm picturing this: if the batwing bushings have 1/4" compliance off center in both directions, then as I transition left to right doing a slalom, the whole rear suspension is "sloshing" 1/2" total back and forth under the chassis. Not as big a deal as uncontrolled camber change, but still unwanted.
Correct ! you will lose camber when its loaded , ths may also reduce stress off the U-joints

Last edited by Rob31; 12-03-2016 at 12:18 PM.
Old 12-03-2016, 12:20 PM
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BOOT77
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The Banski camber rods deletes the cam bolts n replace them with regular and square plates. I have a smart strut kit, but I bought some plates form Banski(cheap so not worth my hassle) to delete my cam bolts and adjust camber with the rods. I would use Banski but my use is drag.

I bought some poly batwing bushings with intention to use them as a template for delrin or solid alum, a local guy should be able to make me some this winter.
Old 12-03-2016, 12:31 PM
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MatthewMiller
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Originally Posted by Rob31
Correct ! you will lose camber when its loaded , ths may also reduce stress off the U-joints
The control arms (camber rods and halfshafts) are both mounted to the center section (batwing subframe). So if the whole batwing assembly moves laterally under the unibody, the mounting points for the arms move with it. No loss of camber occurs. The only way loss of camber can occur is if the mounting points for the control arms move relative to the subframe. That is where the Banski camber rods help a lot.
Old 12-03-2016, 01:25 PM
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Rob31
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Originally Posted by MatthewMiller
The control arms (camber rods and halfshafts) are both mounted to the center section (batwing subframe). So if the whole batwing assembly moves laterally under the unibody, the mounting points for the arms move with it. No loss of camber occurs. The only way loss of camber can occur is if the mounting points for the control arms move relative to the subframe. That is where the Banski camber rods help a lot.
I can agree with this . When the car was on jacks I ran the wheel through its travel noted the camber .(.spring out ) It had lots of camber .
Then after seeing pics of the car in a corner I noticed the camber was (looked almost Zero )Im still trying to explain this
Old 12-03-2016, 01:54 PM
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Originally Posted by Rob31
I can agree with this . When the car was on jacks I ran the wheel through its travel noted the camber .(.spring out ) It had lots of camber .
Then after seeing pics of the car in a corner I noticed the camber was (looked almost Zero )Im still trying to explain this
On jacks, as the wheel goes upward into compression, you should be seeing negative camber, right? That's called "camber gain" (or more correctly "negative camber gain"). That's with no actual loads on the car and the frame remaining parallel to the ground - i.e. no lean angle. When you are actually cornering, the frame/body has significant lean angle toward the outside of the corner. If there were no camber gain built into the suspension geometry (equal-length control arms set parallel to each other), then the wheels would lean the same amount as the body rolled. For example, if the body rolled 5* then the outside wheel would get 5* positive camber relative to the ground and the inside tire would get 5* negative camber relative to the ground (top of both tires leaning toward outside of the turn). The purpose of the camber gain in the suspension geometry is to counteract that lean-induced camber on the outside tire. The goal is to keep the wheel vertical or a bit negative in camber relative to the ground, regardless lean angle. The inside wheel is less important.

So that's why if you see pics of your car cornering, and the pic is showing the outside wheels, you'll see them having little or no negative camber (if you're lucky! or positive camber if the geometry isn't compensating fully for the lean angle). If you see a pic of the inside wheels you'll probably see a fair amount of negative camber relative to the ground, though. Just keep in mind that even if your suspension and subframe have zero play in the bushings, this will still happen. It's a function of body roll, not compliance. In a fully stock suspension compliance with rubber in all bushings, compliance is an addition factor making it worse.
Old 12-03-2016, 02:01 PM
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Rob31
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I figured what I was seeing was the effect of body roll . . But the gain in static ride height(from new batwing bushing ) and the tires rubbing in a corner told me something was moving around . the batwing bushings were the only untouched part in my car .


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