The Stovebolt Site Forums The Shop Area The HiPo Shop Watt's linkage vs. Panhard

Has anyone fabed up or instaleed a Watt's linkage system for the rear end of their street ride? If so, how did you make up the transfer bar sitting on the center line of the driveshaft? I looked into the engineering of a Panhard bar and don't like the inherent error generated by the arc it travels through as the axel moves up and down. thanks

Put the linkage behind the differential with the tranfer bar vertical or on top or below the differential with the transfer bar mounted horizontally, it works either way. The Panhard bar will work adequately on most trucks be cause it can be long enough and the suspension range is limited with heavy duty springs. Also look at the WOB link and Mumford link for other ideas.

BELTFED, I THINK BALDY'S RIGHT, AS LONG AS THE
PANHARD BAR IS LONG, AND VERY CLOSE TO HARIZONTAL
THERE IS'NT MUCH OF AN ARC TO BE CONCERNED
ABOUT.......GOOD LUCK.

I've had a couplke of street rods with watts links and maybe it's just the one I bought, but they seemed pretty fragile. Maybe okay for something that never sees bad pavement. The single pan hard bars are my choice. I know alot has to do with the quality of the install, but the panhards seem stronger overall IMO..
mv

Beltfed,

What are your goals with your truck? That is always my first question as your goals will determain what is best.

IE something that is bagged that needs 5-6" of suspension travel, even a long PH can affect the axle centerline causing issues with tire rubbage and u-joints.

But a PHB can work well on a road course and auto cross if set up right. Well enough where most drivers won't notice the difference in feel to a Watts link.

If it's for bling factor, the Watts link will win hands down.

The other consideration would be interference by the panhard bar with mufflers and/or gastanks.

If you're running one of the popular 4-link kits with the panhard bar that runs from the bottom of the driver's side chassis 4-link mount to the passenger side axle mount, then you'll have a hell of a time getting am exhaust system through without lots of bending. That's a voice of experience. The Watts link won't give you this hassle.

Conversely if you've put a gastank behind your axle, the Watts link is going to make things mighty tight back there.

I'll see if I can dig up a little animation I had of Watts vs Panhard. It was geared towards bagged vehicles but explained and showed the differences well. I think it was done by the same guy who had done the animation showing the differences between forward and rear facing 4-links, 2 links etc.

Robin

I would think the PHB might make make running the exhaust easier if the brackets were made right. I need to do mine for my 63 and I am planing on making the frame mount sit on the bottom of the drivers frame rail as close to the tire as possible. For the rearend bracket, I'll get it as close to the stock LCA mounting point with it being level with the axle line and only a few inches from the rear cover on the diff.

I currently have a 3" X-pipe going to dual mufflers in front of the axle (Warlocks, built like a flow but you can uncork them). I will then neck down to 2 1/2" go over the axle and PHB to a 3rd dual 2 1/2" to single 3" out muffler. I also have a fuel cell that is currenlty mounted behind the axle which I will move up so the bottom of it is almost level with the floor of the bed. The 3rd muffler will sit bellow that with a heat shield.

There is no way I would be able to do that with a Watts link. I feel there is even less obstruction with a properly laid out PHB than a Watts link.

Unfortunately my bed is on and I realize mine is 53 not a 63 so differences obviously apply, but there is little to no room to run any kind of pipe much further back than maybe 6" behind the cab with the php setup you get with a 4-link from people like TCI. That's just my experience installing one.

This is an edited photo to give you an idea:

http://i16.photobucket.com/albums/b8/robin58/illustration.jpg

Obviously a different 4-link and a different php will result in different needs/problems. However I was specifically referring to the one that comes with the most popular kits sold by retailers dealing with our older model trucks.

Robin,

That is not a Pan Hard Bar. That is a Z-bar (Z-link). This picture represtens what a Pan Hard Bar set up would look like.

http://73-ls1.com/misc/illustration.jpg

This might give you an idea of how I ran my exhaust.

http://73-ls1.com/misc/illustration2.JPG

I'd beg to differ on whether or not that is a panhard bar or not under the strict interpretations of a php being a bar that prevents side to side movement of the axle.

However, the point which I'll make for the THIRD time is that the most commonly sold kit for these trucks includes that bar. The installation of that bar makes it hard as heck to install an exhaust.

Call it whatever you want. All I was trying to point out was the various pitfalls of options that are out there.

Robin,

We can agree to disagree on that that bar is called, however, if you go to companies such as Art Morrison, Chris Alston and many other chassis shop's websites, they clearly call the diagnal bar either a "diagnal bar" "Z-bar/Z-link" not a Pan Hard Bar. Where they do call it a Pan Hard Bar, it is as I have described.

To add to that if you picked up books such as Suspension Engineering by Herb Adams, he explains the different rear locators such as a PHB, Watts link and Z-link (diagnal bar). I'm not sure why the company you purchased your suspension from calls it that, but they are calling it a PHB in error.

One of the differences with a diagnal bar and a PHB is what happens with the rear centering when the suspension is compressed. With a diagnal bar, if you compressed one tire with a sway bar attached the other would go up as well and both tires would stay centered. With a PHB, once the one side is compressed the other side compresses as well but, the bar changes its length based on how far it is compressed shifting the rear to one side slightly.

The problem with a diagnal bar is the bending force that comes in to play in hard cornering with a bump (road racing ect). As the passanger tire is compressed it want to push/pull the front link on the front driver side. Under the same cornering force, the PHB doesn't see the same bending force as its connecting points allow it to move the rear to one side or the other based on it's level with axle centerline.

As far as mounting the exhaust, you are probably right about it being dificult, I was not there to see the angles ect you were dealing with.

Please don't take what I am saying as an insult, I'm just trying to correct the term you are using based on the rear suspension research I have done.

A French guy named Panhard (prounounced pan-ard), invented that particular suspension piece. Lots of people call it pan-hard but they are mispronouncing it. Whatever you choose to call it, a Watts (invented by a guy named Watts) linkage does the same thing, but does not follow the arc of the one piece Panhard bar, so is probably better if built properly, but only a minimal difference in handling. Formula 1 cars use the Watts, since they are dealing with small portions of seconds per lap so a little is a lot, and the money is HUGE so cost is not a consideration, since the Watts costs a bit more than the Panhard bar (O.K. call it a Z bar or whatever), on a street driven car it would be hardly noticeable.

As long as we are gaining an education with respect to origins of the term panhard, check this link for additional information.
http://en.wikipedia.org/wiki/Panhard

So does this mean we can drive our Panhard to the bar?