Crazy spring idea and Konis! Feedback please?
 

I have a

You've left the "motion ratios" out of the calculations. Since the shock is mounted inboard of the hub on the lower control arm, the end of the shock moves less than the wheel does. The effect of that mounting position is to make the spring's effect on the wheel weaker than if the spring were acting directly on the wheel.

Also, the motion ratio for the front suspension might not be the same as the motion ratio for the rear suspension (in general, they are different).

This seems to be a very interesting direction. Has anyone mounted springs of the same rates all around on Yellows with spring/perch/sleeves, and noted the height of the sleeve-perch relative to the stock perch, when the car is at it's stock height? This could address Orthonormal's point.

Guy

Stupid question...

Regardless of whether the 218 lb/in/in spring or the 291 lb/in/in is on the front of the car, the ride height in the front in either case should be identical, since the weight distribution of the car is 50/50, right? Given this logic, appearance-wise, one should not be able to tell the difference from stock, if one had all 291's on all 4 corners. Am I wrong?

Having already done similar experiments I can tell you that '00 rears '00 fronts '03 fronts make only minor difference in ride height at either end of the car .