For the purpose of this explanation, I'm using RaceSimTools, hereby referred to as RST. RaceRoom or Sector3Studios are not affiliated with RST, but it is a tool I personally find very useful. I'll begin by explaining a bit about the purpose of a damper. They're there to control or stop the oscillations of the suspension's springs as they move either due to acceleration (longitudinal or lateral) or as the wheels travel over uneven surfaces. Without dampers the suspension would continue to oscillate after every force event. Such behaviour would mean that the tyres would rarely be in contact with the ground, severely harming grip, drivability and thus lap times. From that you might ask, why not run as much damping as possible? Well, then you end up with tyres which will have to soak up all of the road bumps, over stressing them, causing excessive heat build up and bouncing. Therefore a middle ground had to be found in order to optimise grip, where the loads on the tyres vary as little as possible. Keeping a tyre in constant, consistent contact with the road surface will always provide the best the best grip. There are two ranges with which we describe and adjust damper behaviour: Low speed damping Approximately +25 to -25mm/s damper speed is referred to as the low speed range. Damper velocities in this range are caused by weight transfer. When you jump on the brakes, turn in or get on the accelerator pedal, the dampers are caused to move within this velocity range. Tuning within this range can be done on driver feel, although consulting data often optimises the results. High speed damping Anything over +-25mm/s constitutes the high speed range. Dampers are caused to move at these speeds by road obstacles such as bumps and curbs. Too much damping in this range can make a car unable to soak up curbs, causing 2-wheeling and instability over uneven surfaces. Too little will cause a loss of grip due to high-frequency oscillations. Optimal tuning within this range is not possible on driver feel. I have found that tuning dampers is done most effectively on our Nurburgring Nordschleife. The high frequency of bumps and a fairly even spread of right and left hand turns provides excellent none-skewed data. That is something I have to consider, where default setups have to work equally on clockwise and anti-clockwise circuits. However, don't be surprised if you end up with asymmetrical damper settings by following the steps in this thread. It's also very useful that the timing line is crossed as you drive down the pitlane, so you can record a lap without having to do an out-lap first.