You can source dampers with one two or three (or more) adjustments.
1. Low speed bump up to around 2" per second that controls turn in, control over hard braking, long undulations etc.
2. High speed bump above 2" per second that is the ability to absorb road surface irregularities such as a very coarser surface.
3. Rebound.
OR set them in ratios.
Typically the ratio of low speed bump to rebound is around 1:3 for a road car to minimise bump forces but control oscillations, or 1:2 for a sports car to create more ability to turn in, or 1:1 for a race car where turn in rules over comfort.
The high velocity bump should be as close to flat as possible (so force not increasing much with velocity), some trick dampers can actually reduce force over say 2" per second.
The 2" per second is typical for a road car, maybe up to 3" or 4" per second for a race car as you hit bumps faster so the damper velocity is higher.
For critical damping so any oscillation dies in one cycle the Force:Velocity slope is 2xsqrt(mass x spring rate). For a road car use 30% critical, a sports car 70% and for a race car around 100%.
Make the suspension adjustable and they will adjust it wrong -- look what they can do to a Weber carburetor in just a few moments of stupidity with a screwdriver.
