Just out of technical interest do the dampers use magnetorheological damping or something else?

may have spelled that wrong!  2011 4.4 TDV8 Vogue SE
1993 Discovery 1 3.5 V8i

Yes, magnetorheological - Delphi/BWI MagneRide.

Thanks for confirming. That must be what the wires are for!

Bet they are expensive!! 2011 4.4 TDV8 Vogue SE
1993 Discovery 1 3.5 V8i

VERY expensive yes sir

Very interesting how these posts tend to clump together!

According to the WSM the dampers have an orifice that bypasses the valves. The orifice opening is ecu-controlled.

Extract from the WSM:

The adaptive dynamics dampers are monotube, nitrogen gas and oil filled units. The dampers are continuously variable, which allows
the damping force to be electrically adjusted when the vehicle is being driven. The dampers provide the optimum compromise
between vehicle control and ride comfort. To maintain wheel travel, the rear dampers feature an additional external accumulator. This is to provide adequate rebound travel by recovering the volume through the external source. All the dampers have an electrical
connector on the end of the piston rod, in the center of the top mount.
In each damper, the damping adjustment is achieved by a solenoid operated variable orifice, which opens up an alternative path for
oil flow within the damper. When de-energized the bypass is closed and all the oil flows through the main (firm) piston. When
energized the solenoid moves an armature and control blade, which work against a spring. The control blade incorporates an orifice
which slides inside a sintered housing to open up the bypass as required. In compression, oil flows from the lower portion of the damper through a hollow piston rod, a separate soft (comfort) valve, the slider housing and orifice and into the upper portion of the
damper, thereby bypassing the main (firm) valve. In rebound the oil flows in the opposite direction.
In the firm setting oil flows through the main (firm) valve only, but when the bypass is opened by any amount the oil flows through
both valves in a pressure balance. When fully energized the solenoid moves the armature and therefore the slider to the maximum
extension and opens the orifice completely. The damper operates continuously between these two boundary conditions.
The solenoid in each damper is operated by a 526 Hz PWM signal from the ADM. When fully energized, the ADM applies a 1.5 A
current to operate the damper in the soft setting. When de-energized (0.0 A) the damper is in the firm setting. The current varies
continuously as required to increase and decrease the damping individually in each of the dampers.


Usng my IIDtoool, I have recalibrated mine a couple of times on different surfaces to vary the damping between too soft and too firm.

thats interesting re the calibration, how do you do that then? ... - .- -.




Y. O. L. O.
.

Well they are nothing like the way magnetorheological dampers work. They work by changing the viscosity of the fluid in the damper by applying a magnetic field controlled by an ecu........ apparently!

So which type do I have then? 2011 4.4 TDV8 Vogue SE
1993 Discovery 1 3.5 V8i

GraemeS,
Thanks for the explanation, it certainly accounts for the noticeable change in ride comfort when the wires break.👍👍

Cheers
Mike. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

Looks like I have the nitrogen gas and oil filled units as described by GreameS. I wonder if the Delphi MagneRide ones can be fitted when the time comes to replace the originals. Even if they fitted I guess they use a different ecu. 2011 4.4 TDV8 Vogue SE
1993 Discovery 1 3.5 V8i

stan wrote:

thats interesting re the calibration, how do you do that then?

thanks graeme..

so on a smooth road the dampers will calibrate to soft...if, after calibrating like this you go onto a rough road, will it be a softer ride? ... - .- -.




Y. O. L. O.
.

A softer ride but perhaps wallowing, even on secondary roads not necessarily particularly rough roads. Striking the right balance might take a few calibrations. If the ride is too soft then find a bumpier surface for another calibration, perhaps noting what stretches of road are used so that in future when they get too soft, another calibration can be done on the same stretch of road to restore the desired ride. Mine had deteriorated to the point that I was about to order a pair of Bilstein replacements for the rear to see if they tidied-up the ride enough to warrant replacing the fronts too, but found the calibration option just in time. When they eventually are too worn to do a proper job and new ones fitted then another calibration will be needed otherwise the ride will be far too firm.

didnt think of the possible 'wallow' effect..i think i'll leave well alone in case i mess it up...thanks chap  ... - .- -.




Y. O. L. O.
.

Interesting - this is a cutaway from the 2010 press pack, which shows what looks like (I think) a Bilstein DampTronic damper (as per the manual excerpt above). Most part numbers for the combined shock/bag/strut unit suggest BWI/Delphi as OEM though.

Click image to enlarge