Hi all.
MX5 uprights and wishbones. Track narrowed 80mm.
Escort rack, inner balljoints sit on a line drawn between upper and lower wishbone pivots.
Track rods parallel with lower wishbone, which at ride height is paralell to the ground.
Wheelbase significantly longer than mx5, so Akerman is way out because of both dimensional changes.
Moving the rack back and forward changes the steering efficiency. For a steering input resulting in 50mm left/right movement of the rack, I can get anywhere from 5 to 10 degrees of steering angle.
The ratio of the inner and outer wheel angles also changes.
I'll keep reading, but my fallback solution is to take the fore/aft measurement from the MNR chassis I have sitting here. Same wheelbase/track so it'll be in the ballpark.