Spring rate help?

Originally Posted by j-rho

Couple thoughts:
The swaybar only behaves like a spring in roll, but not in dive/squat. If you take off the bar and up the spring enough to achieve the same roll stiffness, the car will squat less under acceleration.

If you're somewhat ok with balance but want to try removing the rear bar, upping rear spring rate in conjunction makes sense. The exact amount to do so you won't really know without testing. There are a lot of things like bushings and a chassis that flex, to make actual swaybar effectiveness less than theoretical - not to mention a small mis-measurement in bar motion ratio, can have a large effect on its apparent contribution. The suggestion of someone above, to get lots of spring pairs, is a good one. Some racer groups even have spring pools people trade in and out of, to make stuff like this cheaper/easier. If you think 300 is too big a jump, try doing half that - a 30% increase (500->650) in spring rate should be readily noticeable but not shocking.

The side-to-side thing of bars is generally misunderstood. If you remove the rear bar and substitute a stiffer rear spring that achieves the exact same roll stiffness, the load on the inside rear wheel at a given lateral g, would be the same as it was before with the bar. People thing the bar is "holding up" the inside rear wheel, instead of thinking about it as a natural effect of lateral load transfer.

FWIW, the fast guys I know of with these cars, are running rates in the upper half of what Shamu provided - around 1200 front, 850 rear.