Consider a typical R/C damper unit: you have oil of a certain viscosity passing through orifices of a certain diameter at a certain speed. Some oil flows around the outside of the piston, this is almost always laminar, since the gap between the piston and the housing is so narrow, so it creates a lot of drag. For the oil flowing through the holes in the piston however, it's hard to predict. When the shaft speed is very low it will be laminar, and when it's high it will be turbulent. Exactly when the transition will happen is hard to predict, but easy to feel: because the resistance of the shock is proportional to the shaft speed when the flow is still laminar, and proportional to the shaft speed squared the very next moment, when the flow has turned turbulent, it feels like a kind of hydraulic lock has occurred because the difference in resistance is usually quite substantial. The transition is sometimes also described as 'pack'; it feels as if the shock 'packs up'.

This effect can both be useful and unwanted: it can prevent your car from slapping the ground when landing from a jump, but it can also make your car bounce very badly over sharp ruts or bumps taken at high speed. So it's pretty important to get this adjustment right.

The way to achieve this is to select the right piston and shock oil: both the combination of a piston with small holes and a low viscosity oil and the combination of a piston with large holes and a high viscosity oil will yield the same static damping; it will feel the same when you bump your car by hand. It will also make the car handle the same in low-speed transitions, such as smooth cornering and low-frequency bumps. But the real difference is in the high-speed damping: the first combination will pack up very rapidly because of the low viscosity fluid and the increased fluid velocity. (the same amount of oil has to pass through smaller holes in the same amount of time, so its speed must be higher) The second combination will have a relatively high resistance to turbulence, because of the very thick fluid which flows at a much lower speed. Hence, turbulence will occur at much higher shaft speeds, or it may not occur at all.

ORIGINAL: zzman

R/C GEEK ALERT !!!!!! LMAO

R/C GEEK ALERT !!!!!! LMAO

So so true