I think there is some confusion here.
Porpoising is oscillations caused by the floor stalling and unstalling repetitively.
"Vowles said the bouncing is simply a function of the car striking the track: “What is happening now is that the car is lower, as a result of fixing the first issue, but now hitting the deck quite hard, and that’s creating the bouncing that you see at the moment."
https://us.motorspor...g/10322631/amp/
Not much confusion. It was what I meant but it was early and I was not quite awake. Oscillation is 'the repetitive or periodic variation, typically in time, of some measure about a central value or between two or more different states'. Different than bouncing, indeed.