Yes, stock valving just can not keep up with performance springs. The correct answer is heat. Try this at home. Put palms together. slowly rub them back and forth with till finger tips touch heel of palm.(stock spring/ stroke) Now do the same thing, but only move from top of palm to heel, but at twice the rate. More heat. The shorter stroke doesn't give area time to cool. Add stiffer springs,making things happen quicker, and you just have more heat that seals, valves can handle. Note most performance struts slow compression, but leave rebound close to the same. Gas shocks seperate oil from air, as was mentioned. This prevents bubbles from getting into oil, which defeats the whole damping idea.Simple answer as I can think of. Does that make sense?
