Antidive / antisquat geometry

[bigblock]

Hello,
from many suspension geometries I have seen so far, the most common srategy for antidive and antisquat is to create an angle between suspensions mounts line and ground so that the bottom mount is lower than the forward mount.

Now, it seems that is an usual design principle to do it in the upper arm while the mounts of lower arm remain parallel. This will also help to increase caster when the wheel moves upward. Correct ??

But I have also seen some designs (Dodoge Viper - rear suspension) where the angled mounts line is on the lower arms while the upper arm remain parallel to ground.

Is it correct to say that in this case the caster angle descrease in a steady corner ? what are the main difference to achive antidive / antisquat working to the upper arm mountsrather than the lower arm mounts ?

I hope that it make sense....

[Rideway]

It is right that when the lower is the arm that is parallel to the ground, the caster increases on bump and viceversa. With the caster change, a camber change is also induced. The more positive caster, the more negative camber change.

Appart from that and installation issues, cant think in another difference and wont have access to MscAdams for a while, so maybe someone can bring their knowledge to light

[Rideway]

I have done with the Lotus Suspension Analysis program a quick example with similar A-arms in width and make one of the parallel to the ground. Steering arm remained unvariable and so did damper-spring.





As you might see, the difference is minimal in camber, castor and antidive variation. This was only checked in bump/rebound. I might do a test on car roll if I have time later.

[Belatti]

What a good answer, rideway! Kudos for that!