sway bar endlink angle

[hai1206vn]

I've been running my Progress front bar at the middle setting. Now I wanna try the stiffest setting. Without changing the endlink length, I have this:


Or I can lengthen the endlink to have it perpendicular to the swaybar.

Which set up is stiffer? (Keep in mind that point B can only move more or less vertically.)

[Def]

They're both the same stiffness. The two situations will load the control arm differently(more torsion at extreme angles), but it should take the same amount of vertical force on the control arm to deflect the sway bar a given amount since the sway bar to control arm geometry is fixed by the chassis of the car.

[hai1206vn]

so you're saying the angle of the endlink has no effect at all? Very interesting!!

If that's the case, the stiffest setting is guaranteed to be stiffer than the middle setting, regardless of endlink angle/length. Correct?

[Def]

Actually, I drew out a freebody diagram thinking the result might not be intuitive - I was right. Even though you've got the same lever arm length, as the sway bar goes more "vertical" the bar goes from being in torsion with suspension movement to more bending from the bushing outward. It's not going to move much in this direction, so it will get stiffer as it goes off perpendicular in relation to the LCA(horizontal).

The effect is very small until you get it over 45 degrees from horizontal though, so not sure it'll really influence stuff much.

But to answer your question, yes, it will definitely get stiff going to a shorter lever arm regardless of the endlink relationship unless things are REALLY moving around. I can't see how they would with the holes less than an inch away in most cases.

[hai1206vn]

Thanks. I think I get it now.

One more thing about the 2 pictures: wouldn't the perpendicular setup make it initially stiffer, just before things swing up?

[Def]

It will continue to get stiffer as the bar goes from perpendicular to vertical.

The angle between the endlink and the bar has no effect on stiffness as the control arm sees it.