mad_machine said:
In reply to clshore :
basically you are talking about a "twist beam" as used by many FWD cars, but as a RWD DeDion axle.
Somewhat similar, but with significantly different design goals and implementation:
The goal of the twist beam is minimal production cost, along with packaging that achieves minimal intrusion into the passenger/cargo space.
Wheel camber and toe are managed by a beam having minimal cross section, wheel 'caster' and fore/aft location is managed by a single
trailing link on each side, rigidly attached to the the hubs. Lateral wheel location is provided by bending in the joint between the trailing link
on each side where they join the beam.
This imparts significant bending loads that require both the beam and links to be somewhat heavy, along with the joints between them.
The goal of the Floppy-D is to achieve the camber behavior of a Live axle (and DeDion), combined with unsprung weight comparable to IRS.
Care is taken to avoid stressing major components in bending, instead resolving the forces by triangulation, and employing multiple links
with spherical joints to directly take the suspension loads into the chassis, as in IRS design, to save unsprung weight.
Cost and packaging are definitely secondary issues for Floppy-D.
Here's a question: Have any production cars employed 'twist beam' on a driven rear axle?
I know that there have been AWD versions of some FWD econoboxes that employed 'twist beam' rear suspension.