zzr1200
Well-Known Member
OK get an air bag with no load applied to it and put 2 psi in. It will be fully extended. Now put a 1/4 ton weight on top of it and see how much air pressure you have to put in it for it to reach the same extended position. If the volume of air is increased the pressure within the bag also has to increase to extend it and carry the load. The higher the suspension is set the more air pressure is in it and the more resistant to compression it is. It is basically a infinatly variable rate spring. If you put 10 psi inside a football 10 inches in diameter and take it 200 feet under water it will be the size of an orange. You would have to inflate it to equal the water pressure at that depth to return it to it's normal size. Hypothetically, say you have 60 psi inside an air bag at standard ride height. If you then load the vehicle, the air pressure within the bag has to be increase to maintain the vehicle at that height. If no pressure was added it would sink as do coil springs. So the more weight that is added to the vehicle for a given height setting the more air pressure is required. That is why when you get out of the car and the suspension is unloaded you hear ticking, that is the valve block releasing air to return the suspension to the selected height setting.
I agree with the above but the original question reffered to a harsh ride, the vehicles weight doesn't change once its moving apart from the fuel used so the pressure in the airbags/ride height shouldn't change.
The difference in ride heights will be controlled by the EAS, as the weight of the vehicle hasn't changed apart from used fuel, the airbags pressure to support the vehicle weight will not have changed, only the amount of air in the bag.
I'd be looking at suspension bushes and shockers.