I recently upgraded the suspension of my '08 S4 to include PSS9's and H+R sway bars. Coilovers set to "5" front and rear. Sway bars in milder position. When driving on Interstate highway at highway speeds, the nose of the car tends to bounce when it encounters gentle dips or swells in the road. In hard turns on highway or other roads it is fine. All four tires at 40lbs. Car height is at tallest setting for PSS9's. Lowered about 1" from stock. Alignment is good. No other mods.

Has anyone encountered this before? I know there was a post by someone who had carefully analyzed Bilstein coilover setup and I think he described this tendency. Any ways to correct for it?

and the rear down a click or two.

Thanks Dr.quattro. I figured I would try something like that to start.

(and I have the Ohlins), you want to keep a few clicks of difference between the front and back. I think I remember Jason (at STaSIS) saying at least five clicks difference to start. When he handed over my S4 he had it at 15 clicks from the firmest on the rear and 10 clicks from the firmest on the front. I have since made it 10 clicks from firmest on the rear and 5 clicks from firmest on the front. The front end is pretty neutral at this point...FWIW I have the front lower dampers at 7 clicks from firmest...

On Friday, installer took car to try to eliminate problem. After trying several combinations, the solution, surprisingly, was to reduce damping pressure in front shocks two clicks. Apparently, this brought the springs and shocks closer to their "ideal" ratios. Nose is significantly less bouncy and no noticable difference in cornering.

While Bilstein may be onto something from a marketing point of view with adjustable damping, there is likely to be only one "ideal" solution for a particular car assuming a relatively stock car is the starting point. Unless you can control every aspect of the shocks performance; compression, rebound, spring rates and so on, there are going to be lots of compromises.

So...my car handles much better than stock but is not as sporty as I would like.

Anyway, thanks for your input.

and I agree with you...development that the factory makes is to specifics. However, I do know that the amount Audi spends on the suspension is very, very little money (for parts)....think less than $100 a corner.