Discussion in 'The Garage' started by K5thatShmobs, Mar 20, 2003.
Just finished these... let me know what you think.
Hate to say it, but I don't think that is going to help. When the axle wraps, the center of rotation is about where your rear bushings are. Those should be near the bottom of the axle... Out here those forward mounts wouldn't last long either, rocks would rake them right off (or hang you hard). Good luck...
are those stacked block's i see in the second pic /forums/images/graemlins/confused.gif
yeah, axles don't warp about the center, they wrap about the leaf spring. if the center of rotation was the middle of the axle then blocks would HELP with axle wrap, giving the axle less leverage.
I can say those are NOT stacked blocks, just new spring perches.
Your workmanship looks good. I can tell you spent some time putting it all together. I share many of the concerns in posts above, but I'm interested in your ideas on the aproach. You have heavily arched springs which could help to resist wrap so it will probably feel better than before the bars. But, the tires anchor the driveshafts well, and the leaf springs make a flimsy anchor for the axle housing to the frame. When you load up that rear end, the axle housing will naturally try and rotate the opposite direction of the axle shafts and will do so to the extent the leaf packs will allow it, which is wrap up. The blocks exagerate this by moving the axle farther from the spring (which is the only thing keeping the housing from spinning) and gives it more leverage. That results in less power to create the same amount of wrap. Now creating a hard link from the frame to the top of the axle tube means that under forward accelleration, the axle housing is pulling at the bar. Since the bar can't change length but the springs can, the bar becomes a leverage point for the axle housing to rotate forward on and forces the spring to wrap. I have a feeling this is just a first step of something larger that your working on so you've got my interest.
I made some front mounts similar to yours, you'd be suprised how hard those bars can pull at them, so don't be suprised if you break one. I managed to shear off a grade 8 9/16" bolt and 2 grade 8 7/16" bolts on one of my track bar mounts at the frame, yours looks to be only one.
Appreciate the valuable input... and no those arent stacked blocks (yeah right)... thats a solid steel spring perch under a block. I was thinking of maybe running two more bars to the bottom of the axle? (four-link) Also, maybe a pumpkin mounted brace of some sort with two hiem-ended bars coming from it might be another idea... Heres a little something.. Excuse the crude bracketing... this is just an idea afterall.
For axle wrap, much better. But those front brackets are gonna get bashed... Why stick them way out there??? I think it might even bind enough to notice. The leaf mounted axle wants to come down and forward, more-or-less rotating around the front bushing. With the front down like that, it's going to want to resist that circular motion. Like parallel links of similar lengths and mounting points, the axle wants to go more or less straight up and down...
Also, unfortunately they are more vulnerable down there too. You should probably make them a bit beefier. Pretty easy to just sleeve it (depending on size) later, that way you can go ahead and try it on the street and ramp. I would do it before real wheeling though...
Yeah those brackets in the drawing are very crude... something much stouter would have to be designed. It kinda sucks that they would have to be so low, too... Where else to mount them... Heres yet another pumpkin-mounted scenario:
That is more along the lines of what I was thinking. I am no expert by any means though. But that is more like the setups I have seen in the past, and that have proven to work. Also, it isn't against the rules to shave that 14bff. Its just free ground clearence.
Look at Borrego's for mounting ideas. Forward inside or outside the rails. Rear on lower side of axle, bottom of brackets roughly flush with bottom of housing. Watch for body mount and spring mount clearance.
Mounted high like that would control wrap in an ideal world. However, this type of system uses the front of the leaf springs for triangulation. Bars mounted high put the spring in compression which doesn't work well, it will bow and may even kink. Bottom line, it doesn't work well like that. With the bar mounted low, spring is in tensions and it works much better. It's a bit more complicated than that but there is the gist. Seriously, look at Borrego's recent post (and some from the past). He's pretty much covered this by actually trying it. No theories there, he explains what actually happened when he tried the various configs (mostly agrees with theory but some unexpected things showed up)...
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