panhard vs wattlink vs wishbone?

[SuperB70]

Hey all!

First,have to apologize my english.

I'm new in here on this forum.

I'm not new in fabricating cars and chassis.

Here I've been watching car porn at project update almost year now and now I have to ask this:

Without putting anyone or they skills down

I am blown away with stuff seen in here.

Why do guy's built they rear ends with panhard and wattlinks

when there is much easyer and stronger way to do it with wishbone like in a drag chassis?

I know that panhard is not possible to make accurate if you have lot vertical axle travel like in 4-link.

It'll allow sideway axle movement and you have to make horrible brakets to your frame and axle.

When the wattlink is accurate but involves more fab than wishbone. And you have again those bracket...

I've know Wattlink from group II rallycars in Europe into '70 and '80.

It is excellent system but it is so much fabrication and it is not pretty (Read: simple design)

You can built wishbone anywhere around your rearend. Only that it's have to be along your chassis, not sideways like panhard.

And when you get it right, it stay's right regardless how much suspension travel you have.

I use to run with panhard on my blown pro street/touring Swinger, used 4 link,panhard and 30x13.5" Mickey rad Et's.

Had many problems with panhard, then I chance it to wishbone, had none sence and have to say that I really did drive it,

a lot, I did make trips to foreign countrys and so on.

[Bryce]

I will take a stab at this.

I think the wishbone would limit suspension articulation, it would bind in body roll. At what degree of body roll does it bind? I dont know off the top of my head. So that would be the main reason. It would be like ladder bar for the street, it can work but not ideal.

Second, I think watts look amazing. Here is my solution to a watts link, I have not seen this design yet.

[exwestracer]

Actually, if constructed correctly, the wishbone is about as bind free as you can get.

There are 2 definitions of a wishbone...

The off-road guys refer to triangulated upper links with a single pivot on the axle housing (basically a trinagulated 4 link design). No real problems with that, except you have a relatively high, non-adjustable roll center (the axle pivot).

Drag racers refer to a Y shaped assembly that mounts between the lower links of a straight 4 link suspension. This design won't allow quite as much roll, and offers a very low, non-adjustable roll center. Either type should perform well enough, as long as the link angles are at least 60deg to each other.

[exwestracer]

Originally Posted by 5280/4

I will take a stab at this.

I think the wishbone would limit suspension articulation, it would bind in body roll. At what degree of body roll does it bind? I dont know off the top of my head. So that would be the main reason. It would be like ladder bar for the street, it can work but not ideal.

Second, I think watts look amazing. Here is my solution to a watts link, I have not seen this design yet.

You don't really need the adjustment holes out at the ends of the axle housing. Those points can be at any height (within reason), as long as the relative height difference is the same as the center to center distance on the bellcrank. Adjustment out there only puts the Watts in a different point in it's natural travel.

We've built a number of those "reversed" Watts links. The only issue with them is the roll center height moves with suspension travel (fixed roll moment). If the bellcrank is fixed to the axle housing, then the roll center is fixed in relation to the ground (roll moment changes with travel).

[Bryce]

Ray I agree about the adjustments on the axle end. Those are not needed. The bars only need to be horizontal at one point during the suspension travel. Those were there as an adjsutment tool to dial everthing in. I may go another route.

As for roll center migration. I want to keep the roll center at a fixed length compared to the the CG height. Therefore you would have the same swaybar at all suspension heights/ roll center heights. You would end up with a stiffer sway bar as the CG of the car lowers, during a bump and vis-a-versa. Also think about the front suspension you have a roll center that typically changes height with ride height changes. So why not match that with the rear suspension.

[exwestracer]

Guess I shouldn't have said "issue", more like "difference".

That design definitely lends itself to use with an anti-roll bar.

[LILBuzzy]

What about if you triangulated the the lower control arms? What would that do with the fixed watts link? Would that even work? Would it work better? I am trying to figure out how I could make something like this work on my impala. It has a single upper link RT side, and two triangulated lower likes. All are adjustable as it was a "sleepy" street car. I had a diagonal bar on it, but now that I am changing games, I need a different device. I really like the watts look over the panhard bar. It may win out in the end though. Any ideas?

Richie

[Bryce]

Originally Posted by exwestracer

Guess I shouldn't have said "issue", more like "difference".

That design definitely lends itself to use with an anti-roll bar.

Yep, that was the plan another tuning device.

[exwestracer]

Originally Posted by LILBuzzy

What about if you triangulated the the lower control arms? What would that do with the fixed watts link? Would that even work? Would it work better? I am trying to figure out how I could make something like this work on my impala. It has a single upper link RT side, and two triangulated lower likes. All are adjustable as it was a "sleepy" street car. I had a diagonal bar on it, but now that I am changing games, I need a different device. I really like the watts look over the panhard bar. It may win out in the end though. Any ideas?

Richie

The lowers aren't really "triangulated" in the sense that they are the lateral locating device. You only need (and can use) 1 lateral locating device. The triangulated lowers with straight uppers are called a "Satchell" link setup.

I would avoid that type of system in a high-horsepwer, big tire car for one reason. Under acceleration, the thrust force from the rear tires is ALL running through the lower links. In that case, it is a good idea to have them parallel to the chassis centerline, and tied directly into the frame.

A Watts link, panhard, etc. should really only be used if all the links run straight.

[Bryce]

Originally Posted by LILBuzzy

What about if you triangulated the the lower control arms? What would that do with the fixed watts link? Would that even work? Would it work better? I am trying to figure out how I could make something like this work on my impala. It has a single upper link RT side, and two triangulated lower likes. All are adjustable as it was a "sleepy" street car. I had a diagonal bar on it, but now that I am changing games, I need a different device. I really like the watts look over the panhard bar. It may win out in the end though. Any ideas?

Richie

Lateral-dynaimcs 3 link uses triangulated lower links with a center upper link and a watts. With triangulated lower links part of the roll center is defined by the intersection point.