I'm curious about something. Has anyone considered running a track bar, panhard rod, or similar lateral limiting device? I was thinking about the fact that the twist beam and trailing links behave similar to a live axle. I realize that these pieces flex quite a bit, but with a rear sway bar and tie bar it might not, correct? I'm just curious if anyone has tried this and what the effects are.
Don't think I'm a guru, but since nobody else has responded maybe I can get something started.
My experience with Panhard rods is that they are/were used on rear wheel drive cars.
Rear wheel drive cars generally have a huge heavy drive axle and a huge heavy differential.
It seems to me that the Panhard rod setup was used to control body roll, i.e. it is more of a way to locate the body than it is to locate the rear axle. More of a ride improver than a handling improver.
Anybody else?
just use for location because most live axle setups would twist up and move side to side if no panhard bar was used other then triangulated systems
I miss my Cavalier, even if it made 100 hp on a cold day and had more suspension then it deserved.
seraph wrote:I'm curious about something. Has anyone considered running a track bar, panhard rod, or similar lateral limiting device? I was thinking about the fact that the twist beam and trailing links behave similar to a live axle. I realize that these pieces flex quite a bit, but with a rear sway bar and tie bar it might not, correct? I'm just curious if anyone has tried this and what the effects are.
You really don't want a Panhard Bar at all. Go over a bump and the body will shift to the side that the rod is attached on. A better design is Watt's linkage, Watts Linkage does the same thing as a Panhard Bar (controls the sideways movement of the rear end) but it moves the rear end straight up and down instead of in an arc like a Panhard Bar. It is on the PT Cruiser and current Mustang, if you want to see/feel. GM finally did a update in nearly 30 years on the twist-beam rear suspension with the upcoming Chevrolet Cruze here in the states. This is what it looks like, as it shares the plaform with the Opel Astra and really does not look like a bad idea to adapt.
Or you can just upgrade to a IRS and call it a day.
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-----The orginal Mr.Goodwrench on the JBO since 11/99-----
Believe me, I had thought of upgrading to irs. I'm also familiar with the watts link from my mini truck days. A lot of guys used them with air ride to keep the axle centered without too much lateral travel. I hadn't thought of using something like that on my car though. Not sure why. Adapting the Cruze rear links (they kinda look and behave like a watts link) sounds like a good idea. But, I was just wondering what kind of effects a lateral limiter would have on this chasis. Would it increase stability or just be too much hassle? I appreciate you guys helping out.
Short answer: panhard bar/watts linkage is not appropriate for our twist-beam, as its designed pivot point does not allow for lateral travel (outside of flex, and a tie rod is more appropriate for that).
Long answer:
The panhard or watts linkage is really primarily useful in solid rear axle suspension setups where the only way the axle is "attached" to the body/frame is through the springs (leaf springs in fairly old cars and lots of trucks even now and coil springs in newer RWD live axle cars, e.g. pre '10 Camaro, and older Mustangs).
Adding a panhard or watts linkage would be pretty hard to even accomplish, and I think you would end up with suspension binding because of it (at least with a panhard you likely would).
Really...lateral shift in the rear suspension of a j-body really isn't a problem, and if it is for you, I want to know what tires you're running because those would have to be seriously sticky...
Now, if you're worried about flex in the ends (out where the wheel bearing is), a tie bar between the ends would help that tremendously. A sway bar just stiffens the whole works (not generally a bad thing for a j-body).
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Sleeper style, they don't see it coming that way.
Thanks!! That is exactly what i wanted to know. I didn't think a panhard would have helped much because of the design of the rear suspension. Still, the idea that was applied to the Astra looks interesting. I had also considered the tie bar. I don't really have a problem with lateral movement, I was just looking for more ideas for stability. Thanks guys!
If you want your semi-independent torsion beam to act like a live axle, then add a "tie bar." And in real world situations, the only time the rear "tie bar" can be beneficial is when you are under 35mph or auto-Xing. If you want stability: stiffer shocks, thicker swaybars, and lower side profile & wider tires is what you'll need. Lowering will help as your center of gravity is now lower and will aid in aerodynamics when confronting with crosswind.
The watts linkage in the upcoming Astra controls lateral movement, but at the same time continues the rear suspension to have a semi-independent movement as well. Our rear suspension is a giant stabilizer bar, but being that it is attached to the other wheel, this design does have it's limits.
>>>For Sale? Clicky!<<<
-----The orginal Mr.Goodwrench on the JBO since 11/99-----
