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Actually, when it comes to handling balance - they can have a LOT to do with each other in this situation where you have a PHB in combination with the OE triangulated 4-link. It will define how stiff (soft, actually) of a bar you can run . . . if you end up running a rear bar at all. Unlike with the S197 and its 3-link + PHB arrangement, details like LCA and (particularly) UCA bushing stiffness, PHB bushing stiffness, and PHB height matter a whole lot.

You have to consider how these components interact with each other in the full 3-D geometric sense. Technically, a tri-4-link plus PHB is overconstrained, meaning that something has to give or else the suspension won't move without offering resistance that can behave very much like adding a huge drag racing "anti-roll bar" along with the relatively soft OE rear bar and trying to take corners at least 'briskly'.

While it may be possible to come up with an overall configuration that feels more linear over most of the range, it will have a built-in tendency for abrupt changes in behavior around peak cornering as the competing definitions of geometric roll center heights move away from each other vertically because of suspension bump or rebound travel.


Norm
 

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If your using a panhard bar with the 4 link setup, it might be worthwhile to look into a PM3L (poor mans 3 link).
 

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Discussion Starter #6
Not doing that. Take off one upper and the axle cranks to the one side out of alignment. Sounds dangerous to me. I don't care whos done it. I'll wait and do it right.
 

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Not doing that. Take off one upper and the axle cranks to the one side out of alignment. Sounds dangerous to me. I don't care whos done it. I'll wait and do it right.
How's it going to do that with a panhard bar attached?
 

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Not doing that. Take off one upper and the axle cranks to the one side out of alignment. Sounds dangerous to me. I don't care whos done it. I'll wait and do it right.
It won't. I ran a PM3L at least three seasons with not a single shift because the PHB controls lateral movement; PM3L controls rotation. Incredible handling improvement with very little investment. You do have to increase rear spring rates just as one would when going to a T/A. Ride quality even improves. But believe what you like.
 

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Not doing that. Take off one upper and the axle cranks to the one side out of alignment. Sounds dangerous to me. I don't care whos done it. I'll wait and do it right.
Once you remove one of the uppers, one of the definitions of geometric roll center disappears along with it. So does the induced roll stiffness (most of it anyway). You probably want to retain compliant bushings in that remaining upper though.

Mathematically, a stick axle needs to have exactly four of the six possible degrees of freedom (3 rotations and 3 translations) under control. That takes exactly four suspension links as long as you aren't asking any of them to do any resistance in bending. Two LCAs, a PHB, and one UCA meets that definition, more or less. Two lowers, two uppers, and a PHB is 5, which clearly does not. All that said, there could be a little crosstalk between the remaining (skewed) UCA and the PHB that I suspect results in a little pinion angle change in side view as the car rolls in a corner. But you wouldn't be looking for max launch bite or max U-joint power transfer efficiency at that instant, as too much of the available tire grip is being used up for the cornering.


Norm
 

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For those of you still running the 4-Link... Do you run a RSB with your Panhard Bar?
I know you are set against running the PM3L. Your call.
To answer your original question: Yes.

I also went from the 5 link Norm describes (MM lowers and PHB with stock uppers, including a rear RSB) to swapping out the rubber bushed uppers to one Heim joint upper. The rear end is smoother, more responsive, more predictable, and overall more controllable.
 

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Discussion Starter #11
I'll wait and just do a TA. But I will say this; the 4-Link definitely binds up.

When I tried to remove my Tailpipes recently with my homemade PHB on the car, I disconnected the left Upper CA to get some wiggle room. In doing so, I could let the axle down far enough to rip the Brake Line off the Axle. Now that I'm installing a real PHB, I can hang the Axle in the air on all 4 CA's and the brake line doesn't even get taught..
 
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