Doc, if I’m wrong, shout me down, but this thinking out loud on the keyboard kind of scares me.
Tough to gauge, and you can’t really tell until the car is fully laden, but how much suspension travel are you anticipating?
With the old setup, the drag link kept everything in the front suspension tied together, side to side. With this setup, you’ve introduced two new motion arcs, mounted to the frame, that weren’t there before. And the only way they can give during suspension movement is by changing the steering angle of their respective wheel.
In my mind’s eye, I’m looking at the frame straight on from the front, and imagining where the arc of suspension travel might occur – nominally, it will be the center of the axle. Then I look at the ends of the rack where they are attached to the tie rod ends. Keeping in mind that the rack is attached to the frame, unlike the drag link, I notice the drop of the tie rod ends from the end of the rack - the new pivot point - to the bell cranks. Note the angle at which the tie rod ends are approaching the bell cranks on the spindles from the rack. I’m putting these images together in my mind and seeing two very different arcs that might work together, but only in a very narrow range, and I’m thinking bump steer.
In the grand picture, yeah, the Sprite is not intended for anything other than some fun, but I recall you mentioning grass drags or dirt drags, which is going to jostle the front end around, and the path of least resistance between these two arcs will be through the bell cranks and to you spindles.
I know there are straight axle arrangements with R&P out there, but the ones I recall had the tie rod ends virtually parallel with the horizon line of the spindles.
Am I tilting at windmills, or is there some fundamental understanding I’ve overlooked? The way it looks now, I think you could go out, jump up and down on the frame, and probably view the change in steering angle while you were doing it.
I'm hoping I’m wrong.
