I am not sure, I had the folks at the independent porsche set it up for road as opposed to track. They suggested the minimum (softest) settings while still lowering the car about an inch.
Even on the least agressive setting it is noticably stiffer than the stock suspension, but I love it. Its interesting how the coilovers work with bumps. Even though the car is lower and stiffer than on stock suspension I have less problem clearing curbs and speed bumps with the bilsteins.
Of course, the best thing is how the car handles, very little body roll when cornering and very responsive. It would be hard to imagine going back to stock suspension setup after the PSS9.
Ed