Can anyone give me a concise explanation on how this works / is calculated relative to an FC? Perhaps a link or a suggest a book that covers this? I haven't been able to dig up much info on fc rear suspension dynamics... Is an e30 rear suspension close enough to use their explanations? TIA!
PS the mobile search is terrible!

 

the E30 is actually very similar. the big difference in the FC rear, is that Mazda's inner pivot isn't fixed, its on a link, and it uses the lateral link to control it.

the net effect is that it still acts like an E30, but the inner pivot moves, so it flattens the camber and toe curves.

 

for what it's worth, I measured the rear bump steer on my FC not too long ago, and it was damn near perfect without me touching it, I was very impressed.

I went to 2" of compression an 1" of droop and it was never off by more than 0.006"

I've heard this is a pretty big problem on E30 BMWs, so the additions mazda made seem to have worked really well.