9000 Aero L4-2290cc 2.3L DOHC Turbo EFI HO (1997)
Suspension Spring ( Coil / Leaf ): Description and Operation
Dampers With Automatic Level Control
The standard rear dampers have been replaced with a Boge Nivomat damper. The rear chassis springs have been replaced with new dampers that are
softer and longer the originals.
The dampers are self-energizing, in that they pump the pressure while the car travels, by using the energy contained in the spring movements. The
pressure is proportional to the load on the suspension allowing the body to remain level even when the car is heavily laden.
The damper comprises of a pump rod, a piston and a piston rod, a pump chamber, and an inner cylinder surrounded by a circular chamber. The piston is
equipped with damping valves that determine the performance of the damper.
The circular chamber is divided into a low pressure chamber and a high pressure chamber. Both chambers contain pressurized fluid. This pressure is
produced by both chambers being filled partly with nitrogen gas. In the low pressure chamber, the gas acts directly on the fluid, where as in the high
pressure chamber the gas and fluid are separated by a rubber diaphragm.
As the damper is extended, fluid is drawn from the low pressure chamber (1) via the pump rod (2) and intake valve (3) into the pump chamber (4). When
the damper is retracted, the liquid in the pump chamber is put under pressure, and the intake valve closes. The outlet valve (5) opens instead and fluid
flows through the inner cylinder (6) and on to the high pressure chamber (9), compressing the gas (10).
The increased pressure acts on the piston, and as the top side of the piston as a greater area than the underside, the piston rod (11) is forced up the bore.
When driving the pumping action occurs repeatedly until the equalization port (12) in the pump rod is opened. Fluid can now flow freely through this
port, from this pressure chamber to the high pressure chamber to the low pressure damper until the pressure in both chambers is the same.
