On a straight, level road, basically nothing.
Cornering, or off-roading, it basically depends on the differential deflection of the sway bar ends.

Working through the dynamics of a particular vehicle sounds like a lot of work. I'd be more inclined to just calculate what it took to push the sway bar to its yield point, or to push the sway bar/end link joint to its maximum angulation or other bind condition.

Mike Halloran
Pembroke Pines, FL, USA

About half a ton for a light truck. I could tell you exactly but then I'd have to shoot you. It very much depends on the vehicle size and the architecture of the link, for instance a link that goes to the spindle has a much higher motion ratio than one to the lower arm so it sees less force.

The big unknown is what is your worst case? There's a good argument to be made that it is jacking one wheel up so the other wheel at that end hangs free. There are dynamic conditions that are worse than that, but that is a good place to start.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

To put a static number on it would require scales or electric force transducers. The circle track guys work with this if they are good players. For us streetrodders we have to use what us available from the aftermarket or junkyard.

In my case there were none from either so I made my own. Again the dirt track guys can break anything so discounting them I don’t think I’ve ever seen a broken link or bolt that wasn’t heavily rusted. To give you some numbers most car front anti roll bars have links of 3/8-24 unf threads on both ends. Many are mounted in polyurethane bushings....Energy Suspension parts.

My 41 Willys replica car always rode stiff in the rear but because of the very narrow rear end there was poor roll control. While aftermarket has anti roll bar kits there simply was nothing that fit my car. Most were too long or too heavy....race car stuff. So I made my own from 4130 tubing. It had pretty short movement so it amplified the rough ride on rough streets. Especially going over bumps with one side. I reduced the rear spring rate as much as possible and had the shocks revolved using a shock dyno. There is only so much you can do with the equipment I had on the car without ver extensive modifications. The anti roll bar was a bit stiff at first but controlled the roll nicely. I the made special links with very heavy die springs and relatively short movement. This eased the harshness over bumps on one side or the other. I used 3/8-16 unc grade 8 bolts in standard 3/8” rod ends. I never has any problems with the bolts,rod ends, links or the actual bar assembly. So the bottom line is 3/8” grade 8 fasteners will hold up for street cars.

Obviously the faster you travel and the higher the bump you hit will sharply increase the loads, and a loose bolt isn’t going to last long

My ‘77 El Camino weighs about 4000 pounds and all the aftermarket anti roll bars, front and rear have 3/8” hardware. The links on the rear are like small tierod ends mounted in formed metal holders. 12k miles and there is no visible wear.

Byron