djos wrote: ↑
Tue Mar 01, 2022 11:16 pm
Apparently no one likes my bump-stop theory?
Not much, because it's the tire sidewalls that dominate in the compliance stack, so changing the suspension is relatively small beer. It might work, but its really an aerolastic problem, an aerodynamic solution will treat the root cause, everything else is a bodge. Newey's book describes the same issue at Leyton House.
Imagine a venturi hinged at the rear axle, riding on a spring at the front. The ground comes up (or the front spring compresses due to braking etc, the venturi gap closes, the venturi creates more downforce, sucking the spring down even more, and then the flow chokes or stalls, stops developing as much downforce, the spring extends, the flow sorts itself out again, downforce builds, and here we go again. The fundamental issue with F1 suspension is that the tire vertical compliance is essentially undamped.
The test would be whether it is at the wheelhop frequency, related to the front axle weight and radial rate of the tires.