Hope this isn't too OT because you are dealing with the front, but here are some of the elements you're discussing, but used in the rear. Food for thought. The key thing here is the spring trailing ends are floating in a guide that is part of, and on the top of the rear radius rod that encircles the axle housing and allows it to rotate slightly as it's arc is controlled by the torque tube. Nothing binds. The clamped ends of the spring are on a pad that is welded to a shaft that passes through the tube frame supported by a bushed, welded-in tube. There is an adjusting arm on the end of the shaft that allows for ride height adjustment instead of re-arching springs or using a jacking screw. A panhard rod is the lateral locator.
I have had really good results with my 1/4's. I drilled holes in the axle and used t-bucket spring hangers and bushings to connect the shackles. I run split wishbones, and the rear lever shocks off a Triumph. The car handles great and goes arrow straight. I wish I had used them on the rear.
I'd like to see more of this one... and more period. I've gone from pondering doing just the rears... to now pondering doing all four corners.
Doing 1/4's in the rear is a great way to eliminate the need for any frame over the axle. I considered doing it, but since I had wanted conventional shocks, I just went with coil overs. Remember that as the rear articulates (like having one tire on a curb), it will want to bring the end of the spring towards the centerline of the vehicle. same issues as a 4 link. the less travel, the less issue, but good bushings will go a long way to relieving stress from binding.
Good article right here! http://www.streetrodderweb.com/tech...sing_posies_elliptslide_spring_kit/index.html In the caption below the final picture... they do mention him using a panhard bar with his system contrary to what some folks have said about there being no need for a panhard bar or watts link. What's the general consensus on this matter?
I run them on my last three cars, with a nonshackle mount the panhard bar does absolutely nothing but add strain to the set up. But i know someone will not understand that so run one of you must. However if there is no side movement what is the panhard bar there for? The rail to the left has a single 1/4 eliphtic BTW. Don
Don, they work fine with a shackle as well (with bones or hairpins). The shackle just has to be bridged (plated) to make sure it can't fold sideways. I love 'em... Definetely no panhard needed...
I've got another question on 1/4 elliptics. In this design, using the radius rod and leaf as a four-link, the radius rods are angled. It reads this is to prevent binding, but in a "normal" 4-bar front the upper and lower rods are parallel. How is this design, with the spring acting as the lower link, different and why does it require the angled upper link? Thanks.
If the springs are held tightly within the frame, the top links do not need to be angled; in fact, they force the system to have 2 different roll centers, which can cause binding as the chassis leans. One other concern with the system pictured is the amount of arch in the leaves. I'm sure they weren't planning on a lot of travel, but as the springs compress, they are going to get longer, the upper links will get shorter as they arc up from level. Looks like the possibility of a lot of caster change with suspension travel with that one.
I agree, and the issue may go further than that. I say may 'cause I'm far from an expert, but it would seem to me that; the "4 link" intention of this setup is actually an illusion. A 4 link will travel in a fixed position, as it uses 4 bars + a spring. The shackles on this setup would let the spring do it's job without changing the axle aspect with respect to the frame (like a traditional buggy spring/radius rod setup), but the heim joints at the axle will let the axle rotate. The only thing keeping the axle steady is the weight of the vehicle on it, but when the weight is released (like when going over a bump) there could be uncontrolled movement of the axle. Not saying it won't work (it's probably fine), the spring may always keep tension on the axle, even when jacked up, but I think Id rather see the radius rod firmly fixed to the axle, or have 4 rods with heims + the spring. Again, I could be wrong. Rebuttals?
Pictures? Sure, sorry, i was away for a couple of weeks. Dragster also to the left is a single 1/4 eliphtic. Run straight as an arrow whether i steer it or not. Yelow Jeep altered is a double. Dragster is a different style of 1/4 eliphtic but i think it wil turn out to be good as well. Very stable setup. A minumum of parts and a minimum of problems. (So far none. )Almost too simple which confuses most of us. Once you have used it you wonder why you didnt always use it. Don For a better look simply use the zoom feature to the right hand bottom of your screen (+100%)
after read this and many other threads this all reads like stereo instructions- this what what i gathered, am i correct? you can run hair pins or split wishbones, with a shackle you can run the "4 bar"(one bar and the spring as the other) with no shackle no panard is needed b/c it creates binding, being it moves in a arc i plan to use hair pins or split wish bones in the front what is the best setup for 1/4's in the back? do you need a panard bar in the rear? i would like to have the look of the rear being suspended to nothing in the back- i was planning on ladder bars- who sells a rear setup other then speedway? what about split wish bones or hair pins? i want to avoid them at all costs- they are the wal mart of hotrods and racing.
Here's the rear of the one I've been building. Ladder bars keep the axle from twisting (anti-roll), so the springs work fine in the center. This thing is just going to be a fairground cruiser...I wouldn't do this on anything I expected to handle well...
Hey, I'll throw my .02 in I guess. Suspension is fun! I work at Posies-we sell a lot of quarter elliptic kits and guys love them. We don't get any complaints about them. I'll go dig up some pics but Troy used them on the most recent pickup he built for poteet on the front and the rear, did some real trick stuff with them. Also I know rolling bones has used them too but I haven't studied they're ways of doing it. Cosmo is dead on with what hes saying, follow his instructions if you can. The biggest fail I see with guys using 1/4 elliptics is putting a bind in the suspension. The IC's of the spring and the longitudinal locators are usually where the fault occurs. Shackles are your friend in this case. If you do something very different and aren't sure if you're going to have a bind or not, what you can do is mock up your suspension mounting points-make sure they are dead on and tight, and replace the spring with a rod. This isn't ideal because a leave with lengthen as it compresses (the rod, obviously, will not), but it will still help you in reference to possible bind in IC's. Once everything is locked down use a jack (or yourself, if you feel strong) and run the suspension through its anticipated range of motion. If everything looks good and nothing is binding, run it further in each direction. Don't know if that'll help you much but I felt like commenting
even if the ladder bars are mounted in the center of the chassis? i plan to drive the car so handling is somewhat of a factor i was thinking like these with the red frame http://www.jalopyjournal.com/forum/showthread.php?t=253504
Ladder bars running to the center of the chassis are "truck arms", and they will not limit roll in the same way. The springs would need to be out at the ends of the axle, as normal. It would handle better in that way.
thanks for the help- is the consensus on the panard bar is that its still that its not needed with hairpins and shackles in the front?
As long as the shackes are reinforced so they won't fold under side load, the springs should hold the axle under normal use. A panhard bar will try to move the axle in an arc, which will bind with the springs if you have much travel.
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