[tirwin]

Lowering a 911 without any other adjustments reduces the suspension travel distance. It could be that what you're feeling is the suspension maxing out. I have a friend that has this problem on his '83 right now. We went for a ride the other day and you can feel and hear it. He is in need of a suspension refresh and we're talking through options and budget now.

As Bill mentioned, a custom digressive valve job does wonders. How much resistance the strut provides is a function of strut compression speed and force. With a normal strut the response curve is linear. With a digressive valve the response is non-linear. The goal is to get comfort when you want it and stiffness when you need it. Low force and compression velocity and the suspension is relatively soft. High force and compression velocity and it gets really stiff. It can be a beautiful thing.