I had forgotten the 3 different back spacing's I have used to get here and mindlessly used the difference of the two arm lengths to guess track. That is incorrect. The drawing below shows how far out we have moved things. Our track is very close to 54 (8" rim 4" BS). The rotor hats are .280 thick so that puts us at 54.715. We cannot run anymore backspace as the calipers are within .020 of the spokes.
Scrub is still reasonable with the more vertical SAI because we were able to move the lower ball joint closer to the center of the wheel.
I sprung the car @ 2hz on paper some time back, because of the improved motion ratio and reduced shock angle, we are able to get 2hz with a 325 lb spring instead of 450.
I have been using a suspension analyzer on this suspension for the last couple of years and after a lot of hours I learned that if I move the upper pickup points 3.015 outboard, the front roll center does not migrate vertically or horizontally at 2 degrees of roll. I read somewhere that the UCA being 60% of the lower will typically achieve good timing between the two arcs. Moving the pivot outboard makes the new arm 63% the length of the lower. Seemed like a good sanity check. With this timing and static camber @ -1.5 the outer wheel is vertical at 2 deg roll.
This is the new upper pivot axle beam we are going to try. Also working on a new bearing housing out at the end. This will allow us to tip the shock out a little more. Thinking of running stress analysis on the cantilevered shock mount, the pivot axle, and the CA bearing housing.
Some pictures of the tire with respect to the flare.
No spacer, no extended ball joint, lower arm parallel to ground.
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