Hydractive and non hydractive, ride quality

vince · Post by **vince** » 23 Jul 2008, 06:21

Guys, i have a VSX with Hydractive,

Normally it rides super smooth. When you put it into "sport" suspension mode it handles alot better on bends and the road noise increases ever so slightly but unless you concentrate you cant really tell that much difference.

What i want to know is how much difference is it supposed to make? Is mine already kind of stuck in sports mode?

Post by **RichardW** » 23 Jul 2008, 07:47

Normally when you press the 'sport' button nothing should happen - all it does is increase the sensitivity of the system for switching to hard mode. If it was stuck in hard mode all the time it would be very stiff (like Ford Focus stiff

) all the time.

Post by **CitroJim** » 23 Jul 2008, 07:54

Hi Vince,

Sounds like everything is in good working order there to me

The function of the comfort/sport switch is to adjust the thresholds when the suspension switches to hard mode. In sport mode the suspension will switch much more readily, hence the better handling. You will not notice any obvious, immediate change if you switch modes as it is a bit subtle.

The Hydractive system takes cues from the speed, rate of accelleration/decelleration and rate of change of steering input. Using all this information and the mode you select, the Hydractive ECu then makes the decisions on when to switch.

The Citroen Technical Guide gives a lot of information on how the Hydractive system works and has tables of the switching thresholds.

The comfort/sport switch even has a fair effect on an Activa, tightening up the already tight suspension quite significantly when sport is selected and it is being hustled along B roads

pete_wood_uk · Post by **pete_wood_uk** » 23 Jul 2008, 14:43

Yup, sounds like it's working. As a quick check: Park the car on the drive with the engine running, and the suspension should be in "soft" mode. Applying pressure to bonnet or boot (I tend to use my arse

) should result in lots of travel. Very soft at the back, less so at the front. Stop the engine, and you'll probably hear a whistle which is the AC powering the solenoids holding the hydractive "soft" valves open. Lock the car up, and after a few seconds the whistle will stop and there'll be a click. Apply your nether regions again, and it should be a lot harder. That's hard mode.

As Jim says, unless you actually thump the switch in the middle of a series of bends, then you shouldn't notice any actual difference when you do so. I tend to drive mostly with the car in sport mode - it doesn't hurt the ride and there's less uncertainty as you approach a bend...

(Having said all that, mine's getting a bit hard all round now and sinking at the back when parked - I rang Mr Pleides the other day for some sphere pricing....)

Cheers
Pete

Post by **xantia_v6** » 23 Jul 2008, 18:48

Another test which I have used is to find a very quiet country road, and with ther suspension in soft mode mover the steering wheel to weave across two lanes as fast as comfortable at obout 35-40MPH, then while continueing to weave accross the road, hit the suspension switch, and you should feel the suspension tighten up.

vince · Post by **vince** » 23 Jul 2008, 19:44

Thanks guys.....some good advice there.....im not trying to find anything wrong with it honestly

It does definately make a difference when in sports to cornering...its on rails.

Im getting a full set of new tyres on saturday...some nice softer compound ones...all the same tread aswell on look like new alloys....i cant wait

Will no doubt help handling also somewhat.

I stil cant get over how amazing the ride is in this car....it puts the past Xantias i have had to shame....

DickieG · Post by **DickieG** » 23 Jul 2008, 21:08

A simple test to see whether the electric side of Hydractive is working is to tune the radio to 171 LW, when its in hard mode the radio interference noise is reduced. The easiest way to switch the suspension into hard mode is to apply or release the accelerator quickly.

Post by **CitroJim** » 23 Jul 2008, 21:20

DickieG wrote:A simple test to see whether the electric side of Hydractive is working is to tune the radio to 171 LW

I noticed the radio in my new Activa was tuned to that station when I first drove it Richard

Stempy · Post by **Stempy** » 23 Jul 2008, 21:35

Another method is to remove the fuse to the HA ECU, than go for a drive, it will disable the electrovalves so soft mode can't be activated. You'll know what hard mode is all about then! (Remove dentures first)

pete_wood_uk · Post by **pete_wood_uk** » 24 Jul 2008, 08:28

vince wrote:It does definately make a difference when in sports to cornering...its on rails.

Oh yes indeed

. See my rather disparaging post a few months ago about the handling of my new C5 in comparison.

vince wrote:Im getting a full set of new tyres on saturday...some nice softer compound ones...all the same tread aswell on look like new alloys....i cant wait Will no doubt help handling also somewhat.

Just out of interest, what tyres are you putting on it...?

Cheers
Pete

vince · Post by **vince** » 24 Jul 2008, 19:51

They will be the same OE size, but will be Kumho Ecsta's

I can speak from personal experience in a potential to be fatal emergency stop scenario they perform very well.