17 replies to this topic

[tiger99]

But dampers are incapable of producing a static force. I think the problem has been mis-described, and the car is coming up, but slowly.

[GraemeC]

Gas filled dampers do have a little pressure in them and will (although minutely) assist the springs/cones.  

You can witness this by the fact they self extend when compressed by hand, whereas oil filled will stay wherever you leave them.   Some gas ones are actually very difficult to compress by hand.

[tiger99]

Yes, but as you correctly say, it ASSISTS the spring. I was simplifying because its static force is unimportant and certainly not implicated here. It is also fixed for a given damper extension, i.e. will not vary due to adjustment of the damping control, as no gas is added to or removed from the damper. Gas does expand as the temperature rises so a car with gas filled dampers may sit a couple of mm higher on a hot day, and if driven hard on a bumpy road to heat the dampers will also rise.

 

I was thinking that some of the comments made above were defying the Laws of Physics. Adjust the damping and the car fails to return to normal ride height. Even then it should sink slowly as the damping piston has no need for leak-free seals and is normally lubricated by the fluid.  Maybe just about possible if the adjuster closes its valve port fully (a design error), the piston is abnormally tight, and they have forgotten to drill the fixed bypass hole, but that should show up on factory test.

 

Yet we see wrong advice connecting dampers and ride height given frequently on this and other internet forums.