I recently asked Joel about sway bar setup. He spoke of the spring rates in his answer as well. Maybe this can help on both.
"Sway bar setup does depend a bit upon your driving style but I played with several before settling on what I have now.
Spring rates also come into play here since we're talking about overall roll rates of the car. I would suggest the most common spring rate splits (all numbers in kilogram per millimeter) would be a 6/5 front rear, on the mild end. 8/6 for a dual purpose track and streetcar. 9/7 is getting beyond streetable but can work well on the track.
If you're in that general vicinity, then my favorite sway bar setup, playing with off the shelf bars, was a racing beat front bar combined with a stock rear bar.
After that I decided I wanted even less rear bar, to help keep things planted coming out of corners.
Mathematically, the same overall torsional spring rates front to rear worked out to a 1 and 1/4 speedway style hollow bar with an 1/8" inch wall thickness, plus no rear bar. While t's technically adjustable with variable holes (yes and heim joint end links) I never really have. Overall it dropped about 20 lb and it's right where I want the balance to be. It's basically about halfway between the stock from bar and the racing beat front bar with no rear.
I am on an 8/6 spring rate by the way. The setup has been good enough to help me win my region's SSM autocross class for the last 5 years running."
Hope that helps,
Joel Payne
