Panhard bars...how is yours mounted?

I've been looking at Panhard bars for a while and I've noticed that some are anchored to the chassis on the passenger side and the axle on the driver's side while others are the opposite. The Burban's bar is anchored to the axle on the driver's side.

This is a Kenny Brown set up on an '04 Mustang:

This is a hand built set up on a Mark VII:

Here's a Griggs unit:

Here's a Maximum Motorsports set up:

I'm sure each arrangement has it's advantages and drawbacks, but is there a wrong way to build/mount one?

I assume "no" is the answer, but I don't like to ASSume!

I can't remember if it was an article I read or a t.v. show I watched but I do remember a mention of Nascar teams using opposing anchoring strategies for oval and road course cars; one was anchored to the driver's side of the axle and the other was on the passenger's side but I don't remember which was which.

in both my rwd Corollas the bar mounts to the chassis on the passenger side, and to the axle on the driverside.

My Corolla All-Trac uses a similar solid axle set up in the rear as the rwd cars, with the difference being the panhard bar mounts are reversed

If the bar is level like it should be, the difference is miniscule. Mount it in the direction that makes it easiest to fabricate and clear the exhaust.

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The one I fabbed up for my Fox Mustang was a close mirror copy to the MM design. I just flipped the axle side mount to the passenger side instead of the driver's side. It was a fair amount of work as I recall. I couldn't afford to buy the whole MM kit so I decided to make/modify my own parts. It's surprising what a motivated person can make out of old bed frames and scrap steel.

Yeah, I remember reading something about mounting the bar one way being "better" than the other but if you want to get that picky, do a watts link instead.

In reply to Moving_Target:

I had considered snagging a watts from a Panther at the bone yard and trying to adapt it to the Lincoln, but a panhard bar would be much simpler and easier to install.

Why did you move the axle mount to the passenger side? Clearance issues?

Do you have a build thread for that '86?

Our Busch car was set up to mount the chassis end on the right side for ovals and the left side for road courses as they mostly turned right. Moving it from one side to the other seemed to make no difference though.

The issue is that under roll, a panhard bar shifts the axle laterally. The higher your roll rate, the less important its positioning is going to be.

Back when I was thinking about this a lot more, my idea was that the best setup would be to have the axle-side mount higher than the chassis mount. What that should do is "push" the body more to the inside of the corner.

I've never created an opportunity to test that idea, though.

I can't see where putting the pivot on one side or the other would make any real difference. The big things about a Panhard are: it needs to be level with the car at ride height, it needs to be as long as possible to minimize side to side axle movement and it needs to not bind.

The mounts need to be STRONG. A Panhard has a LOT of stress put on it, don't skimp on triangulating the mounts on both the body and the axle. Use good quality rod ends or urethane bushing eyes, if you can't weld well then swallow your pride and find someone who knows what they are doing.

As mentioned in my message to you, I mounted the chassis bracket to the passenger side as it is larger and heavier. Offsetting some of the driver's weight.

Curmudgeon wrote: big things about a Panhard are: it needs to be level with the car at ride height, it needs to be as long as possible to minimize side to side axle movement and it needs to not bind.

Number one in your list seems to be the "common knowledge" but is it really the best setup? Being level just means that any change in relative ride height between the the mounts will cause the axle to shift towards the chassis-side mount. Is that really ideal? If you have a bar that rests at an angle, then jounce and droop will shift the axle in different directions. It seems to me that if you have to have some lateral axle motion tied to vertical/roll motion, you'd want that motion to be different for rolling left and rolling right.

Not my diagram

I could see how, according to this diagram, the bar could be moved to different frame mounting points to change the handling of the vehicle for a left-turn oval track application. Put it in mount A and it will transmit thrust down into the right rear and plant it, lifting the left front. Mount C would cause a slight upward thrust to be imparted to the right rear. All things being equal and ideal, that would cause understeer and oversteer, respectively.

Handy for tuning on a roundy-round car, but I assume for my intentions I want long and level. Like Aussie's.

To get super-pedantic about it, a LHD car will corner better towards the left. You could find out which mounting arrangement gives better cornering to the right and mount it that way.

I crewed for three years on a live-axle car with a Panhard bar setup and we learned a number of things.

First, it is important that the bar be parallel to the ground when the car is at static ride height. Otherwise the axle will be forced to move diagonally. A Panhard bar will always generate some lateral movement of the axle just by it's very nature but you want to minimize it. The longer the bar, the less displacement. If you want to eliminate this, use a Watts linkage. Also make sure there is no preload on the bar.

Second, it DOES make a difference which way the bar is mounted (left-side frame vs. right-side frame). On the street you won't notice it, but if you are racing, it matters. Attaching the bar to the frame on the left will work better on right-hand corners and vice versa.

This is not just theory. The original builder of our car had figured this out and built mirror-imaged mounts, since the tracks here in the NW run both clockwise (Portland) and counterclockwise (Seattle). The mirrored mounts allowed the car to be optimized for the particular track. One time we forgot to change the bar after Portland and absolutely could not get the car to come out of 3B at Seattle. We finally realized what had happened, swapped the bar, and it completely transformed the car.

Finally, the height of the Panhard bar affects the rear roll center. The center will be at the point where the bar crosses the centerline of the car.

Like I said, you probably won't feel any of this if you are just street driving.

ReverendDexter wrote: The issue is that under roll, a panhard bar shifts the axle laterally.

Not so much as some would have you believe.

And really, it's not roll that shifts the axle, it's just plain vertical movement. But a 36" long bar has how much sine error over 5-6 inches of travel? The bushings could flex more than that.

Heck, the stock Watts on an RX-7 has more lateral motion than that. It's asymmetrical so they could fit it in front of the axle. If they had room behind the axle, they would have used a Panhard in the first place.

Good post SAKEPWR...so for this car it would be best to put the frame mount on the left side to improve cornering to the right, which will compensate for rather than increase the cornering bias created by having more weight on the left (being a LHD car).

Knurled wrote:

ReverendDexter wrote: The issue is that under roll, a panhard bar shifts the axle laterally.

Not so much as some would have you believe. And really, it's not roll that shifts the axle, it's just plain vertical movement. But a 36" long bar has how much sine error over 5-6 inches of travel? The bushings could flex more than that. Heck, the stock Watts on an RX-7 has more lateral motion than that. It's asymmetrical so they could fit it in front of the axle. If they had room behind the axle, they would have used a Panhard in the first place.

Well, it's not directly coupled to roll, but that roll causes vertical motion of the location of the axle-side mount.

I wasn't aware of how much lateral travel there would be, I was just thinking in terms of moving vs fixed.

Every panhard bar car I've ever owned has the driver's side mounted to the axle and the passenger side to the chassis.

I don't think it really matters, though.

If I'm thinking about this correctly (long odds on that!) I believe which side of the bar is anchored to the chassis determines which side of the rear will have the lower dynamic roll center.

ASSuming a perfectly level bar at static ride height:

With a driver's side chassis mount the rear roll center will be lower when turning right due to body roll placing the chassis mount below the axle mount. When the same car turns left the body roll will bring the chassis mount above the axle mount creating a higher roll center. So that would be a tendency to understeer when turning right and oversteer when turning left. The opposite would be true for the opposite arrangement. But, then again the lateral force transmitted through the bar would somewhat counteract the effect of the body roll by planting the outside tire with a downward thrust angle.

I guess it could all boil down to what I'm willing to deal with and/or try to tune around...

I ASSume the changes are very subtle and there are so many other variables they may not be noticeable at all, at least not at my level of "car prep".

The_Jed wrote: I ASSume the changes are very subtle and there are so many other variables they may not be noticeable at all, at least not at my level of "car prep".

That's really what it boils down to. Worrying how the Panhard is mounted is such an ultra-fine detail compared to, say, worrying about what height it's mounted... which has much more drastic effects on handling, especially if you're using it in a stock four-linked car where you really need the Panhard mounted in concert with the chassis' existing roll center.

The_Jed wrote: In reply to Moving_Target: I had considered snagging a watts from a Panther at the bone yard and trying to adapt it to the Lincoln, but a panhard bar would be much simpler and easier to install. Why did you move the axle mount to the passenger side? Clearance issues? Do you have a build thread for that '86?

I chose doing it the reverse way of the MM bar because I'm an oddball (ask anyone who knows me like streetwiseguy). Most of what I've done is scattered here and there on the 'net. Modified stock k-member, torque arm and panhard bar are the highlights.

http://members.shaw.ca/rlemke/panhard_bar/

The bar was sourced from a circle track place in the states ,the spherical rod ends were sourced locally as was the scrap steel I used.

This discussion has come in the past and I'm not smart enough to regurgitate it accurately so...

http://forums.corral.net/forums/road-racing-auto-x/1197270-panhard-bars-experts-step.html

http://www.corner-carvers.com/forums/showthread.php?t=2806&highlight=ehren

There is a couple of pictures of my attempt at a panhard bar in the first thread link.

In reply to Moving_Target:

Good stuff! What did you do to the K-member?

The stuff outlined in chapter 5?

I've been considering picking up a boneyard K-member and doing that before swapping it in.

About the lateral movement: by making the rod as long as possible the side to side can be minimized. In the case of my car, the total side to side is approximately 5/16" and that's over approximately 6" of travel in a straight line. Since the body rolls in turns, the lateral movement is not really noticeable, or at least I can't feel it. The car is stable and predictable in the rear and since in AX etc we turn both ways I'd have to be able to jump out and swap it side to side between turns. Even NA$CAR ain't that fast.

I considered building a Watt's link using RX7 parts, but on the stock RX2/RX7 axle it's offset to one side and centering it is a big part of a successful Watt's build. (Yeah, the stock RX7 setup is a pretty big compromise.) Making the center mounting strong enough to handle the loads put into it would have meant I wouldn't have clearance between the axle and body, so I went the Panhard route. So far, so good.

About binding: the rod eyes are not the only place where the setup can bind. On a 3 or 4 link, it can bind in the link eyes as the axle moves side to side. On a leaf spring, the springs try to resist the bending forces fed into them and can cause the Panhard to bind. In the average street car this isn't a big deal but in a race car oh yes it can become a big problem in a hurry.

Hey Jed, what's your plan for the rest of the suspension; you're adding a Panhard, what are you doing to the factory upper and lower control arms?