to get softer soft ride?

[Richard Gallagher]

i wonder if it would be possible to put a two colour LED on my hydractive2 switch to show the whether the suspension is in soft or hard.... let me explain how i intend it to would work

the led would work as normal, but the led would change colour depending on the suspension mode...
we all know the switch just makes the sensors more sensitive...

so in the off position, when the suspension goes hard, the led would glow orange, then go off when back in soft mode,

and in the on position, (led green), the led would change colour to orange when it's in hard mode.

Easy enough? In theory it's possible, i don't see why not, I could read the signals from the hydractive computer to the electrovalve, and wire it into the switch, but put a different LED in it.

Apparently there is a diagnositc computer for the hydractive computer that can read all the inputs and outputs, and display then in real time. Oh the possibilites. Something else what would be cool would be to get readings from various points in the hydraulic system of the pressures, and display then dynamically. Of course this is a lot harder.

But what do you think of my switch idea guys?

If you do a search on here then you will find that someone, was it Stempy or Bernie? fitted LED's to the Hydractive valve when they had problems detecting a fault. I believe it was some 6 months ago or more.

[Mandrake]

Yes - but the soft ride disappears already at speeds from some 30Mph and up. You will only enjoy it coasting around town. At highway speed coasting its the rigid drive forever.
Wont help you playing with the button - the computer decides.

The downside is you get a more noticeable shift from soft to hard.

The hydractive (I or II) system can only change between 2 preset states. There is no possibility to have a variable soft/hard -ness. (like the C5 hydractive 3 system)

Hi Anders,

You're thinking of Hydractive 1 only found on early XM's where the "sport mode" basically consists of switching permanently to hard mode over 30Mph. In the "comfort" mode the computer decides when to use each mode.

In Hydractive 2 both hard and soft modes are used at all speeds by the computer and the switch to "sport mode" only lowers the threasholds for most of the sensors.

Regards,
Simon

[Mandrake]

Hi forum,

To get a softer ride while retaining the rigidity of the hard mode can I put a centre sphere with a bigger hole in the middle? Would this technique work?

No,

As the centre sphere doesn't have a damper valve, its like an accumulator sphere in that regard. Instead, there are two damper valves in the Hydractive control block, one on either side in line with the 10mm hydraulic pipes which go to the strut tops.

So if anything it is these valves that you would alter to get softer damping in soft mode without affecting hard mode. But I wouldn't recommend it.

Before trying to modify your system I would highly recommend finishing diagnosing whether there are still any ride problems as Hydractive soft mode should ALREADY be very soft. (Too soft if anything)

Two things which spring to mind are Hydractive centre spheres which are low on gas (unfortunately without a sphere pressure tester or plenty of familiarity with how soft it SHOULD feel you could only take an educated guess about whether they're low) or air bubbles in the system causing harshness in the ride.

Until those two things are confirmed, trying to modify the characteristics of the system would be a mistake IMHO. (Especially when you're still learning the functioning of the system)

Regards,
Simon

[Mandrake]

If you are looking for a softer ride than you could do what I've done and that is to fit sphere's for a non Hydractive Xantia, to your Hydractive one. In my case I use the ones specified for a TD/2.0 which have a larger centre hole which allows the LHM to run in/out of the sphere quicker. The Hydractive sphere's are standard fit.

Whilst some may disagree with my decision, I've made this alteration on a 2.0CT Turbo estate, a 2.0 16V and 2 TD's including the one I've still got and I swear by it.

I must be one of those who would disagree then

I have tried this myself and I was NOT impressed by the result. Basically it softens the damping on both hard and soft modes. Yes, the hard mode became a lot more palatable, but the soft mode was now seriously underdamped, and in the soft mode the front of the car in particular was oscillating up and down over undulations something chronic.

If you drive sedately you'll probably get that soft floaty ride some people might like, but IMHO the handling will go to hell in a handbasket...

For me PERSONALLY, it makes a huge difference and I highly recommend it to anyone looking for a smoother ride. Bear in mind that I do not use my Xantia to charge around like a loony (I get paid to do that at work in their cars. Legally, I might add ).

However what I would say is that with Hydractive, the computer does now switch in earlier on the twisties (because of the sensors on the roll bars etc) which prevents the car getting out of shape.

I don't see how, as Hydractive 2 in fact does NOT measure body roll. (!) Yes there is a sensor on the rollbar but the offset is not far enough from the middle to measure any significant amount of roll, it measures primarily vertical body movement osciallations.

The computer measures mainly the "rate of change" of the movement of the rollbar sensor too, rather than the specific offset, and since body roll is a very slow movement compared to the suspension bottoming in a dip (which is what the sensor is there to detect) it doesn't trigger the computer.

So its likely that it's wishful thinking on your part that the computer switches sooner

Each to their own of course. Some people like the soft floaty ride of a DS, others like the tight handling of a BX or Xantia...

Regards,
Simon

[Mandrake]

i wonder if it would be possible to put a two colour LED on my hydractive2 switch to show the whether the suspension is in soft or hard.... let me explain how i intend it to would work

You mean like this ?



Ok, I confess mine is not two colour, but it could easily have been.

the led would work as normal, but the led would change colour depending on the suspension mode...
we all know the switch just makes the sensors more sensitive...

so in the off position, when the suspension goes hard, the led would glow orange, then go off when back in soft mode,

and in the on position, (led green), the led would change colour to orange when it's in hard mode.

Easy enough? In theory it's possible, i don't see why not, I could read the signals from the hydractive computer to the electrovalve, and wire it into the switch, but put a different LED in it.

The switch as it stands now has a bulb in it, not an LED, and the bulb is also wired to the switch, so you would have some difficulty in modifying it. (I've had the switch apart to try and fix low illumination and its a pig of a thing inside)

Also I think its very important that the LED is within your normal vision line without taking your eyes off the road, if you were looking down at the switch all the time while driving and cornering you will run yourself off the road.

Even fiddling with switching from normal to comfort mode and looking down to see if the light is off or on has caused a couple of close calls for me! So I put my diganostic LED up by the window where it is in my field of view.

Apparently there is a diagnositc computer for the hydractive computer that can read all the inputs and outputs, and display then in real time. Oh the possibilites. Something else what would be cool would be to get readings from various points in the hydraulic system of the pressures, and display then dynamically. Of course this is a lot harder.

But what do you think of my switch idea guys?

Using an LED to diagnose the suspension is a perfectly reasonable idea, and I've had one in my car for months now... It's just connected to the front electrovalve signal (pin 1 on the white plug) via a 100 ohm resistor.

(Now you know why I had the wires in the ECU box bared back already for the diodes )

I wasn't able to find any easy way of getting the wires through the bulkhead though, so as it is temporary I have it coming in through the door...

Regards,
Simon

[deian]

ok simon, point taken, i doubt very much if there is still air in the system now, if any, they will be down by the brake pads maybe, the ride is MUCH better than before since i fixed it.

i guess i will hydraflush her first, and change the other 3 remaining non strut spheres (front centre, and both back ones, what the other rear one for, if you say anti-sink i don't get it, because that feature is just a valve right).

but i still want to do the hydractive led function integrated into the hydractive switch, bernie, if you are still around, got any tips? i read the old post between you and mandrake going on about the switch and led'ing the valve's status, very interesting

[deian]

you beat me to it! but i want to integrate it into the hydractive switch led! any wiring diagrams please?

by the way, my switch's light is ok, it's the one on the dash, and it's green, bulb or not i will do this.

[Mandrake]

you beat me to it! but i want to integrate it into the hydractive switch led! any wiring diagrams please?

by the way, my switch's light is ok, it's the one on the dash, and it's green, bulb or not i will do this.

Ah ok, so the Mk2 has the switch on the dashboard does it ? In the Mk1 the switch is just in front of the height control lever on the centre console, making it very difficult to see safely while driving...

Wiring diagram ? Hardly needed. If you're going to use a 2 colour LED you would have one of the colours wired through about a 470 ohm resistor to the power inside the switch which previously ran the bulb, that would give you your base colour.

Then you'd have to run an additional wire back to inside the ECU box and splice it into the white wire as I showed on my post about the diodes, and connect the second half of the LED through 100 ohms. (As its running off an average of only 3 volts, and you want similar brightness)

Personally I would put the resistor at the ECU end, so that if for some reason your newly run wire should get chafed against the body and short to earth the only harm it will do is stop the LED changing colour, whereas if the resistor was at the LED end it would put a short on the ECU and either prevent it working or do some damage...

You would get 4 different colours with this setup depending on which way around you connect the two halves of the LED:

Switch in comfort, suspension in soft - green
Switch in comfort, suspension in hard - LED off
Switch in sport, suspension in soft - orange
Switch in sport, suspension in hard - red



Regards,
Simon

[bernie]

Yes,I'm still here.

I've posted some pictures.
First is HA switch located next to key on dash, ON

Second is switch OFF


These two show my diagnostic workings with leds and diodes on top of dash.



They are actually wired into the system at the HA ECU end.
They are both dis. at present because I've just fitted 2 brand new HA valves

[deian]

welcome bernie, hi i'm deian, and i'm interested in this issue...

interesting to find your hydractive switch on the other side of the dash, mine is next to the air conditioning switch.

anyway, have you or anyone got any detailed wiring diagrams of the exisiting switch? so i know how/what to modify, first will be getting a dual colour LED to work in one colour, then comes the part of taking a feed off the hydractive valves (which you've proven is possible), then finally, to get the led to work on both states, i believe dual colour led's work by having different voltages applied to them

[JohnCKL]

I think some HA2 are malfunctioning like mine which sticks to hard mode all the time. I still have not found out the problem as car is being overhauled. Perhaps those with hard mode permanently on will benefit from non-HA spheres most. Of course it would be best to find out the cause but in my case, I've regassed all spheres, changed front electrovalve (to used unit) but only slight improvement. I've bounced the front of other HA2 Xantias and they are very soft, perhaps even softer than non-hydractive cars. I will continue to investigate after my car is fixed.

[deian]

Check that the HA comuter has enough voltage, you need at least 12v!

[bernie]

anyway, have you or anyone got any detailed wiring diagrams of the exisiting switch? so i know how/what to modify, first will be getting a dual colour LED to work in one colour, then comes the part of taking a feed off the hydractive valves (which you've proven is possible), then finally, to get the led to work on both states, i believe dual colour led's work by having different voltages applied to them

I've got this one

[deian]

thanks bernie

is that the same as hydractive 2?

now where's my french dictionary?

[Mandrake]

now where's my french dictionary?

He's called Cloggz....



Regards,
Simon