Hydractive 1 and 2 differences.....

vince · Post by **vince** » 28 Dec 2009, 17:01

Firstly.....the following link takes you to a great write up of the legendary Citroen Hydraulic suspension systems. There seem to be a couple of questionable lines in it, one of which forms the basis of this post.

Link: http://en.wikipedia.org/wiki/Hydractive#Hydractive

My question is on the line:
Citroën hydractive (Hydractive 1 and Hydractive 2) suspension was available on several models, including the XM and Xantia, which had a more advanced sub-model known as the Activa. Hydractive 1 suspension systems had two user presets, "Sport" and "Auto". In the "Sport" setting the car's suspension was always kept in its firmest mode. In the "Auto" setting, the suspension was switched from soft to firm mode temporarily when a speed-dependent threshold in accelerator pedal movement, brake pressure, steering wheel angle, or body movement was detected by one of several sensors.[1]

In Hydractive 2 the preset names were changed to "Sport" and "Comfort". In this new version the "Sport" setting would no longer keep the suspension system in firm mode, but instead lowered the thresholds significantly for any of the sensor readings also used in "Comfort" mode, allowing for a similar level of body firmness

I didnt think the Hydractive system on Mk1 Xantia's kept them in hard mode when the button was depressed....even the showroom brochure states that the thresholds for reverting to hard mode are merely lowered by depressing the button....which is what ive always thought.

Opinions?

Sl4yer · Post by **Sl4yer** » 28 Dec 2009, 17:05

I thought H1 was only on the XM, and all Hydractive Xantias were version 2.

James

deian · Post by **deian** » 28 Dec 2009, 17:15

Yes true vince.

The technical descriptions of Hydractive 1 and Hydractive 2 is correct, but Xantia's never had Hydractive 1 so you are correct about the mk1 Xantia's, it was never kept in hard mode via the switch.

Also in H2 the sport mode not only had more sensitive thresholds but it would hold it firm for longer.

DickieG taught me that

deian · Post by **deian** » 28 Dec 2009, 17:18

It's nice to see how many more advantages they have listed compared to the disadvantages!

Post by **CitroJim** » 28 Dec 2009, 19:55

Legend has it that H2 had to wait for ECU and computing technology to catch up with it before it could be used in production cars; the basics of H2 had been about for some time, originally developed on the Activa concept car in the 80s.

There were experiments carried out on the DS to give it Activa anti-roll. Rather than electronics, it used a pendulum in a plumb-bob arrangement to operate a roll corrector and hydraulic rams. It worked apparently...

Citroenmad · Post by **Citroenmad** » 28 Dec 2009, 20:02

I think ive heard of those experiments too Jim, i wonder if Citroen still have that test car in their conservatoire? The Activas are in there too.

I would be fantastic to organise a FCF meeting there, sometimes the Conservatoire is open for group events. I know the Traction Owners Club had an event there a few years ago.

Post by **CitroJim** » 28 Dec 2009, 20:06

Citroenmad wrote: I would be fantastic to organise a FCF meeting there, sometimes the Conservatoire is open for group events.

That Chris, is a brilliant and inspired idea. It would be a dream come true

Very worth looking into...

Citroenmad · Post by **Citroenmad** » 28 Dec 2009, 20:09

Ive no idea how it could be done, who would be the person to contact or anything. But i would certainly be a fantastic event, i dont think even the CCC has had an event there?

The TOC went 2 years ago i think, though im sure it was only 2 hours in the conservatoire, it would be well worth it just to see it. Ive seen a few pictures of what is in there and it looks fantastic.

DickieG · Post by **DickieG** » 28 Dec 2009, 23:12

The CCC are in the process of organising a visit to the conservatoire at the moment, they have had several visits there that I know of. If anyone is a member of the CCC and wishes to go then look on the CCC website/this months magazine for more details.

Citroenmad · Post by **Citroenmad** » 28 Dec 2009, 23:22

Thanks Richard, just found that on the CCC website

Best get your name down Jim!