Suspension hell (kinda long)

[jdbubb@ix.netcom.com (Dan Bubb)]

calimus wrote:
> 
> 
> 3. Also realized that stock sway bars due jack s*&!t since they don't come
> out to the axle area itself ans stop before the bend occures in the arms. (I
> could be wrong here, but from the looks of how it's all setup, I don't think
> so, someone correct me with and explination of what the hell it does if I'm
> wrong)
> 

The trailing arm part of the rear axle (the part that runs from the
bushing back to the spindle mount) is stiff in bending in both a
vertical plane and a horizontal plane. It is also stiff in torsion since
it is a closed section (O). If the trailing arm part of the axle was not
stiff then wheel camber and toe would change noticably under load.
The beam part of the axle is stiff in bending in both a horizontal plane
and a vertical plane and has to be to control camber and toe, but is
weak in torsion due to it's open "T" cross section. The beam needs to be
relatively weak torsionally or the rear tires would not be able to move
up and down independently. 
All a sway bar does it tie the trailing arms together in such a way to
increase the torsional stiffness of the beam. The fact that the factory
sway bar connects halfway out on the trailing arm and not all the way
out to the axle does not matter since the trailing arm is stiff in a
vertical plane and can transmit the vertical force of the sway bar to
the axle without deflection.
Disclaimer: the terms "stiff" and "weak" used above are in relative
terms. The stiffest structure still deflects. So, when I say something
is stiff it means the resulting deflection is small relative to the
loads imposed and the stiffness required to adequately perform its
function.
As usual, if I've gone overboard in the tech terms, let me know and I'll
see if I can explain it better.
Dan