Gathering parts for a 27 track T. I have a tube axle, 1/4 elliptical springs, 4 bar, , reversed covair for side steer, and bolt on bat wings. With the 1/4 elliptical do I need a panhard bar? I would not mind adding one but with the axle out in front of the springs not sure how to mount it. I "assume" the panhard bar would need to be parallel with the axle?
I would assume so. still have to deal with side to side sway thru the shackles. make it as long as possible. be creative, it doesn't have to be perfectly straight. it's not the course that the bar runs, it's the two ends. check out trucks with 4 wheel drive. panhard bars have all sorts of bends to clear obstacles
That mostly depends on how well you have the springs secured to the frame. If you are using light weight bracketry, and or long shackles, yes, install a Panhard rod. If you build a heavy, well supported mount, and short shackles, then no, you should be fine without. A friend of mine angled the springs, to act as a triangular spring arrangement. No Panhard rod. That car road well, handled well, never wore anything out, didn't even chip the paint in the mounts. Mike
Normally no. with 1/4 spring your shackles are facing front to back. A panard bar works side to side.
The first few pages of the Pete and Jakes catalog has a nice description of various front suspension types and when and why a Panhard is needed. I found it helpful when installing mine.
Not such a problem with this car......It has side steering [cowl steering] Any lateral compliance will not be transferred into steering angle changes You NEED a panhard bar with this set up. Ideally it should be the same length [pivot to pivot] AND parallel to the steering drag-link. It doesn't need to be directly above or below the drag link As long as it is parallel [it can be further to the left or right /front or behind] It remedies two things at once 1: sideways movement that 1/4 elliptic suspension could have 2: mechanical bump steer issues caused by having cross steering that arcs laterally combined with suspension that arcs longitudinally
You said that the car I built does not need one, because it has side steer, and you are correct. The OP, and it is on his post you quoted, says he's using a reversed Corvair box, for side steer. Then you go on to accurately explain why you need one with cross steer.
Panhard bar works best when you break a main leaf spring on either side , it helps the car to steer while driving home ! Without bar car wanders right and left , ask me how I know . I drove 175 miles home with broken mono leaf front spring !
You have not really described what you envision for your suspension. Usually (but not necessarily), quarter elliptics are arranged to extend from rigid chassis connections, forward to the axle. They could connect to lugs on the top or bottom of the axle. without shackles, but with rubber bushings to provide some compliance. To prevent axle rotation under braking, another link from the chassis to the axle is required, either below or above the spring. This is analogous to a four-bar linkage arrangement, with one link on each side being the spring. (Best to have the spring on top, so it would be under tension rather than compression when braking.) Alternately, the second link on each side could be another quarter elliptic, maybe even a single leaf. If you intend to use a normal 4-link arrangement to locate the axle fore-and-aft and absorb braking torque, you'll need shackles. These should be of a design that are pretty rigid against deformation from lateral loading (i.e., cornering). (Hairpins are generally a bad idea IMO, but especially with a tubular axle.) Another thing to consider - the wider the spring, and the flatter it is under normal load, the better it is to absorb lateral loads. Also note that with longitudinally mounted quarter elliptics, the attachments to the axle will be much closer together than a transverse spring. This means the springs will need to be much stiffer, if body lean is of concern, with a corresponding increase in ride harhness. Going on a tangent - I have a design concept that I hope to apply someday. The axle will have a convention upper link on each side. The "bottom links" would be essentially an "A-arm", with a links pivoting from a point a couple of feet back on each side's chassis rail, and connecting at the mid-point of the axle. This would fully locate the axle, longitudinally, transversely, and in "bump". This leaves the spring to function only as a spring, so it can be adapted to any type of spring. A transverse spring, or quarter elliptics, could be mounted low and connected by vertical rods to the axle (a la Corvette rear spring).
Sorry I misread his first posting, I thought he meant cross steer. He does not need a panhard for side steer. I suppose I deserve a spanking for this The OP could use the 1/4 elliptic springs as a link [no shackles] but they must be used as the uppers. This puts the leaf under tension when brake torque is applied. Then for the lower links , make an A frame to the centre of the axle. [The A frame will arc the same as the drag link, and also provide lateral support] But most importantly , "experts" will be scratching their heads ,looking at a front end that appears to be only supported by the 1/4 elliptic spring eyes
I think I will give it try without the panhard based on your experience. The mount you show for the 1/4 elliptical on your car are just like the ones with the springs I purchased. Thanks for the info I appreciate it.
Might need to check with @Pocket Nick. This was a customer build, and he did final assembly. I was already off to another shop then.
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