Technical No-bind long ladder bars?

I posted this in response to another post, but thought it might be of interest to those following this post.

"We always used the rule of thumb that the front of the ladder bars, or the intersection point (imaginary lines extended past the bars) of a 4 bar should intersect the line drawn from the contact patch on the tire up through the center of gravity. That means that shorter bars could point more down. Long ladder bars could get the same effect , but had to intersect at a higher point. As cars became lower, packaging made it easier to use shorter bars. Also, less adjustment was required to make a larger difference."

Hope it is of help to someone.

 

Probably getting way too complicated here but, what if you build the bars like normal ladders. Straight with normal dual mount points at the axle, going to the previously discussed center mounted swivel bar in the front. But build the end of the swivel located within a bracket (brackets) that would allow you to bolt/lock the swivel in solid for track days? Would that work and would it be the best of both worlds???
Just thinking here.

Mark

 

I've always wondered what a IRS type suspension would do with ladder bars.

 

Mark,
I was thinking something along the same lines. I have parallel leafs on the back of the stude. I was thinking of using a slider on the front mount for the ladder bar to allow for the spring movement. something like this

 

If you're using a standard ladder bar you can leave the rear, top left bolt, out of the mount on the housing. The other rear mounts should have a large rubber bushings, and the front mounts should be the largest, and best quality heim joint you can get. Front mounts should be wider than the joints, with high misalignment on both sides of the joint. If you're building your own bars, the top left hole in the housing bracket can be slotted and a little oversized so it can move and be bind free. This will allow a bolt to be used in the top left mount if it's not tightened. This setup will allow the body to roll when making a turn, or allow one wheel to roll over a bump bind free. Hope this helps.

 

Also if leaf springs are used, the housing needs to float at the spring . The rear of the ladder bars still need to be mounted as described above.

 

This is more for mostly drag cars that see very little or no street time. I think the OP was talking about a street only car. Perfect front mount for no bind would be on the exact centerline of the front spring eye bolt , but this would be a very short ladder bar and cause great pinion angle changes as the rear moved through its travel. Perfect mount for no pinion angle changes would be on center with the front u-joint, but that will cause great bind at the leaf spring perch, thus needing the housing to float at the spring perch. I'm talking street car here. Best mount for a drag car is in between, as you described.

 

I got a little off here. I just reread, and saw that you wanted to use a buggy style leaf spring. Not much experience here, but I don't think buggy spring should cause to much straight up and down bind. But the ladder bar's mounts should be as I described above.

 

I see suggestions that no panhard bar is needed on a buggy spring setup. I feel it can stabilize a street driver, especially if driven hard. Our roadster handles well but when pushing it hard through a canyon road the front end felt a little "twichey" and unsettled through a corner. The addition of a panard bar seems to take the shackle sideways movement out of it. The car is now very predictable, more so when making transitions right to left.

 

The bars on my Willys are 7' long and they work really well!

 

Hey shooter54 do you have a floater on your rear axle?

 

Currently building a set of 80" ladder bars for an injected Hemi powered 64 Dodge street car. We're going to use an S&W floater in the rear. Should hit the street in the next month and I'll let you know how they work out. Yes I know, impractical, but they look pretty cool and that's what we're after.