As I mentioned last week, with RCA’s banned in most SCCA Solo classes, some creativity is required to modify the roll axis on cars like the AE86 after serious lowering. Luckily, in these same SCCA classes, methods of lateral rear axle placement is almost entirely open. That means that relocation and modification of the existing panhard rod is allowed, or even fitment of the ever drooled over Watt’s Linkage.
In regards to roll center placement however, neither a panhard or a Watt’s (especially a Watt’s actually) compare to what is possible with a Mumford Linkage. Here, the roll center height is the theoretical intersection between the two outer links. That means we could even place the roll center below ground! …Something not possible with any other commonly used linkage. Negatives of the Mumford however, are that careful engineering is required to design a system that (1) will not bind, and (2) will provide appropriate roll centers in roll and bump … especially when packaging it for a car like the AE86! In addition, though for a strict competition car we don’t really care, (3) ground clearance can be a big issue with a Mumford system.
so we engineer a system for dumped corollas…
but are left with ground clearance issues! d’oh!
hah. would give new meaning to under axle exhaust as well.
Re: Ground Clearance and packaging.
If the theoretical roll center is dictated by the intersection of the outer links, is there anything that prevents the outer links from being mounted up high, yet still angled so that your roll centers would still be where you want them to be? …kinda hard to describe without drawings.
I’ll have to investigate how the roll center moves in such a situation, and how the lateral movement of the axle is effected… but yah… that’s about what I had in mind.