Panhard bar
 

I know this will seem like a Noob question but, can anyone explain to me what a panhard bar is? How it works? why its so bad for a streetcar? or provide a link to such information?

Think of it this way. When your car turns, what stops your rear axle from moving side to side? On a stock RX7, it is the Watts Link.

On most cars with a solid rear axle and coil springs, a panhard rod (or panhard bar - same thing) is used. A panhard rod runs parallel to the rear axle. One end is attached to the axle housing on one side, as far as possible to the outer end of the axle. The other end attached to the "frame" or unibody of the vehicle, as far as possible to the outside of the car.

Visualize your rear axle and tires planted to the ground and the body of the car leaning to the right or left. The Panhard rod is what keeps the rear axle (and tires) in proper relation to the rest of the car.

It is not bad at all, per se, for a street car. With the first gen RX7, it is usually criticized because the aftermarket panhard bars availavble have metal bushings which equates to noise for day to day driving.

Purchase "How to Make Your Car Handle" by Fred Puhn for details.

is noise the only major complaint when on the street - i am familar with panhards on other cars such as my firebird - does anyone have a pic of the setup on a first gen. ie, where the welding takes place?

http://www.rpmnet.com/techart/panhard.shtml

Its the noise, and wear/maintenance of rod end bearings.

i just had an idea, why not take one of the watts links and make it a panhard bar with that? does anybody tried it before? maibe is not a bad idea after all

You mean using the long link from the watts? Its too short. But you might be able to scavange something from the junkyard. Like off an F body chevrolet. They used panhard bars.

RX7 Carl is right; maintenance of the rod ends is also an issue.

I would be curious to know if anybody has successfully used a panhard bar on a street car.

What exactly makes all the noise?

The spherical ends are metal bushed and don't "give" like a rubber bushing. That's the major complaint. Handling-wise, a panhard rod makes the rearend really solid with respect to lateral movement. Sometimes this isn't exactly what you want in a street car as the oversteer comes on VERY quickly.

so for a street car your better off just sticking with the watts, how hard is it to replace the stock bushings? what would you look for as far as knowing if they need to be replaced.

I love my panhard for the street! One thing I did do, which pratically eliminated all the noises, was to get super high quality teflon rod ends and used rubber rod end seals. The teflon rod ends have a lot less play...you can barely move them with your hands...it really eliminated the slapping and clunking it had with the regular rod ends that came with the kit. The rubber rod end seals not only keep the dirt and grime out of the rod end, they also eliminate the metal-to-metal contact (slapping noise) that occurs when the bar moves around. Heres a pic of the panhard...check out the seals:
https://www.rx7club.com/attachment.p...postid=2610482


the only other noise that i could see people complaining about is the the gear whine since the trilink mount is on the top of the rear end and the lack of rubber transmits the noise into the cabin...but it's not bad if you ask me. this ain't no caddillac though!

I totally disagree. Just the opposite.

with the disire for a streetcar? or the fact that the oversteer comes on quickly?


if that is true, then why is the panhard supposed to be an improvemet upon the watts link? (besides the fact that the oversteer isn't "snap" oversteer)

Actually, that's not the problem. Tie-rod ends and ball joints, after all, have zero give to them, they are just fancy rod-ends. However, toe-rod ends and ball joints are spring loaded to take up the wear that occurs with any sliding metal-on-metal (or as in the case nowadays, metal-on-plastic for less friction) motion. Rod-ends do not have this. ANY little bit of wear on rod-ends and they start rattling and making a ruckus.

Remember, 90% of NVH is noise. If a car has a very stiff suspension but it makes no noise at all over bumps, the mind often makes it seem much less harsh than a soft suspension that rattles and clunks a lot.

Not true. The Panhard bar's purpose is to lower the rear roll center, which can't be done with a Watts linkage without making the links so low they pose a ground clearance problem. Lowering the rear roll center with no other changes has the effect of reducing the rear suspension's roll stiffness, which REDUCES oversteer. Sometimes to the point where you're plowing mercilessly and picking the inside front tire off the ground. :) Which is why they recommend much stiffer rear springs with the Panhard. The lower roll center also makes the handling more predictable because the roll stiffness doesn't change as drastically with suspension travel. A swingaxle Corvair is an excellent example of what happens when your rear roll center goes too high with respect to center of gravity!

Tell you what, just disregard my post entirely.
Obviously I know absolutely nothing about rotary cars.

both.

peejay just explained it beatifully.

jeeze... you guys make these sound awsome! maybe ill have to make a stop at the junkyard soon. I could have a friend make me some mounts (he has access to a machine shop) and have someone weld them onto my axle and frame.

anyone have suggestons for where to mount the brackets?

I don't have a pahard but I do have full metal bushings on my WATTS. The noice is substantial, as is the vibration and more inportantly, the jarring impacts from bumps. The flip side though, is correcting the rear geometry is the best thing you can possible do for these cars. Be it a modified WATTS or a pahnard bar, it's probably the best thing you can do. If anyone watched the drift video I posted a few days ago, you know what my car handles like. It's amazing how easy the car is to control with some work to the back end.