Opinions on a panhard rod

[blackZ]

I'm getting ready to take the rear end out of the Vega to paint everything. If a panhard rod is absolutely necessary I'll try to figure out how to put one in now before I take it out. Seems to me that if I put one in the rear would move side to side as the suspension moves up and down. I don't think I need one. What do you guys think?

[Barry Donovan]

it is entertaining way to gain a seat.

left front up right rear down..

being a vega, I'd follow mustang success.. all kinds of different ideas.

my subaru for example.. i keep it 100% animal. 1 little sway up front, IFS+IRS.. it just stays animal and seated.

[mike343sharpstick]

Vega has a torque arm suspension, so yes. It needs a torque arm to manage lateral movement.
It will move slightly in a lateral direction when the suspension cycles through it's movement, but that will be minimal based on the stock design with the long panhard rod.

[DanStokes]

The one on my Mustang completely changed it's handling - for the better. I won't go into the details but there are lots of "how-tos" on line to tell you about proper design.

Dan

[Loren]

You have to use something, with your ladder-bar setup. Diagonal links are popular also and a simple install.

[blackZ]

I just wanted to add that the stock suspension had been removed and it now has a 9" with coil overs and ladder bars.
One more question, what will happen if I don't add one right now? I suppose I could always add one later, right?

[Loren]

?! This is 3,000 lbs of metal that can go fast enough to kill you or other people. Might be a good idea to investigate suspension design and use a little further, before trying to drive a car with no solid means of side-to-side axle movement control.

[blackZ]

I'm not a suspension expert but after looking at where and how I would mount a panhard rod it looks to me as though as the suspension travels up the rear would move to the passenger side, and to the drivers side as the suspension moves down. A diagonal link is something I've thought about but I don't know how that would work on the street.

[Loren]

A Panhard rod if used should be mounted level, becomes the roll center normally so height-wise should be around the axle c/l except that a ladder bar deal has no roll, should be as long as possible so that lateral motion through it's arc is minimized, that movement (ideally and inch or so being limited by travel stops or straps up-and-down) should be accommodated in the rest of the suspension (the ladder bars will flex enough). A rigid mount on one side of the frame, cross-braced to the other side, goes on one end and of-course a bracket on the other side to the axle. For tire changes if the axle must drop much there should be an easy release of the bar on one side so the axle is not pulled sideways too much. A Watts link won't have the side-to-side issue but adds a bunch of parts, if the OEM's think a Panhard bar is good enough then I'm with them on that.

All that complication makes a better street suspension than a diagonal link but the latter is much simpler. If your preference would otherwise be to do nothing, at-least use a diagonal link. 4130 is best for stiffness in compression but anything will do if it's big enough, we have a sponsor here that would surely have a kit or something.

[DanStokes]

If you want to get exotic(er) you may want to look into a Watt's link. They prevent side-to-side movement and cause the axle to travel straight up and down - no arc. More fabrication is required but it IS an option.

Dan

[blackZ]

http://chassisengineering.com/index.php?route=product/product&product_id=301

This doesn't seem so bad. I need to see how tall of a bracket I need so I can get the bar as level as possible. I guess the longer the bar the better?

[blackZ]

The $20 must be a miss print unless it's just the bar itself.

[Loren]

Listed as an "(Option)", I'm imagining the $20 is, if your buying a complete suspension system from them that would normally include a diagonal link, for the extra 20 you can substitute the slightly-more-expensive panhard rod instead. That wouldn't be the price for either item on it's own.

[cstmwgn]

Not sure what the intended usage is but if any aggressive cornering is in the program then you need something BEFORE you drive it. If this is going to be a canyon racer or track car (as opposed to a strip car) - the Watts link would be the best solution. With a 9" in the car, mounting the pivot point to the center of the housing is pretty easy.
I run a panhard bar on my car - it goes from the frame rail on the drivers side to the four link bracket on the rear end on the passenger side. The rear end does not move that much in the normal travel of the rear end.

[Huskinhano]

I have a good suspension book I bought a few years back. it goes into a little detail on them. Very interesting. Everyone looks at them in a static condition and pretty much think it holds the rear axle moving sideways. It's also counteracting drive line torque very much like a torque tube The chassis wants to roll one way and the axle wants to roll another. The Panhard fights this and keeps the axle planted better. In turns depending which way you're tuning it's helping keep the tires evenly loaded.

The other thing interesting in the book the author states the Panhard should not be level to the road but split between the travel. The reason is the Panhard will apply forces on the outside tire away from the body and to the road and the inside will try to lift the wheel to help level the car. When you make the bar level to the ground it bias the weight too much one way and can unload the suspension. I can't say that from experience.