Pro Engineer/Dampers
Damper histograms — bump, rebound, and what the shape is telling you
The one setup screen that looks like statistics and is actually a picture of the road.
Springs decide how far the wheel moves. Dampers decide how fast, and that is the half most people never touch because the numbers have no obvious meaning. A histogram gives them one: it counts how often the suspension was moving at each speed, and the shape of that count is a description of the surface you drove over and what your car did about it.
BUMP AND REBOUND
Two directions, two settings, and they do not do the same job.
- Bump controls how fast the wheel is allowed to move up — into the car, when it hits something.
- Rebound controls how fast it comes back down onto the track afterwards.
A car that skates over kerbs has too much bump: the wheel cannot get out of the way, so the whole car is lifted instead. A car that feels like it is still settling when you want to turn has too much rebound: the wheel is taking too long to come back to the road, and a wheel in the air has no grip at any camber.
WHAT THE SHAPE MEANS
Most of a lap is small, fast movements — surface texture, not corners. That is the tall middle of the histogram, and it is where the low-speed damping lives. The wide, low tails are the big events: kerbs, crests, the compression at the bottom of a hill.
A histogram that is all middle and no tails is a car that never used its suspension travel — you can afford softer springs, or you are leaving kerb time on the table.
Tails that reach the edge of the plot are the suspension running out of travel. That is where packers come in, and it is the one place where the fix is not a damper setting at all.
PACKERS: THE THIRD SPRING
A packer is a rubber puck that physically stops the suspension travelling any further. It sounds crude and it is the trick that lets a fast car work at both ends of its speed range.
[ Chassis ]
|
[===] <-- packer, limiting the gap
(Spring)
The problem it solves: at high speed, downforce compresses the car until the floor scrapes, and the usual answer — stiffer springs — ruins the car in slow corners where you want it soft and compliant. A packer stops the travel at the bottom without changing the spring at all. Soft springs for the slow corners, and a hard stop before the floor touches.
WHERE TO SEE IT
Suspension travel is published by Assetto Corsa at every corner of the car, sixty times a second, and Pro Engineer plots it against distance round the lap along with load, camber and slip — so a tail on the histogram is a place on the circuit rather than a number in a table.
Free, no account, nothing uploaded. Download it · the full chapter