2006: Renault mass damper
At the time the F1 circus arrived at Hockenheim, Renault and Alonso were building up a comfortable lead in the championship. However, the FIA decided to interfere and decided to ban the innovative mass damper solution that was used and approved by the FIA since the Brazilian GP of 2005. Although Renault managed to win the title, Pat Symonds recently said that the fuss seriously hampered Renault's progress towards the end of the season.
The mass damper itself was in fact a movable mass inside the nosecone of the car. About 9kg mass could therefore be considered sprung mass, a considerable advantage over the other teams. The device was particularly effective on kerbstones and in acceleration where the inertia of the mass would effectively pull the nose down to the track and increase front end grip.
For large mechanical grip you need a soft suspension with big movements in the vertical plane.
However, you need to control the riding height of the front wing, which means you\'d wish hard springs.
There you have conflicting goals. What you would like is a suspension that stiffens under load (on a side note, the magnetic-rheological suspension could be used theoretically to achieve this).
When under large aerodynamic loads, the springs compress so much that you only have the tire sidewalls working as springs (and they are non-damped). The mass damper can help you amortiguate the load oscillations you get when running over a kerb or in the transitional phase of cornering. It is sort of a \"mechanical emergency patch\" for a car in which the riding height influences enormously the aerodynamic behaviour.