HP suspension existential question

406 V6 · Post by **406 V6** » 02 Sep 2004, 02:13

Hi!
I have this existential question: why does the suspension get more "basketball" like as the height is bigger? the system pressure should be the same, as the weight remaisn equal... or not?
Thanks [:D]

john alexander · Post by **john alexander** » 02 Sep 2004, 03:19

At a guess the higher the car is the greater the pressure in the LHM to lift it therefore the reduction in the springing effect and damping of the nitrogen .thats why I want to know how to lower mine,

tomsheppard · Post by **tomsheppard** » 02 Sep 2004, 13:42

Centre of Gravity rises as does the roll centre.

NiSk · Post by **NiSk** » 02 Sep 2004, 19:23

Both the above answers are correct and influence the "feeling" of the suspension, in addition raising the car on it's suspension reduces the suspesion travel upwards, as does lowering it reduce the suspension travel downwards. This is why it's not a good idea to make permanent higher or lower adjustments to the suspension by adjusting the height correctors. The car's suspension geometry is correct at driving height, all other heights give some form of negative effect. If you really want to raise or lower the car, you will have to relocate the suspension struts so that you have nominal sphere diaghram position retained.
//NiSk

Dave Burns · Post by **Dave Burns** » 03 Sep 2004, 05:42

No the basic height of the car has nothing to do with suspension pressure.
Suspension pressure increases only with loading of the vehicle, otherwise the weight of the car is the same at any height so it follows that the pressure will also be the same, adjustment to the height being brought about by the volume of oil in the suspension cylinders, that oil is at the same pressure unless the car gets heavier due to increased load.
Sphere diaphragm position will hardly be affected due to the same reason so adjusting the height wont affect them, there will be a very small change in the rears due to a change in leverage of the trailing arms, but the fronts are direct so wont be affected at all.
Dave