Hydractive/Activa comparisons

davek-uk · Post by **davek-uk** » 20 Sep 2006, 08:50

Help! Please make me see sense. I’m toying with the idea of building an Activa estate – if it’s possible and if I need to. Has it been done before? Is it worth doing?

Hi all. I've been looking for my next estate, after the Xantia, and have come to the conclusion that I just want better Xantia!

I’ve looked at the C5 but I’d prefer an old oil burner for an engine and less electrics, so that puts me right back with the Xantia. I love my Xantia anyway – so why change? I’d like something at least as comfortable as my LX but better roll control around corners and ABS.

Now to my real question: What is the ride comfort and control like in models with Hydractive or Activa suspension? I’ve never ridden in another hydro Cit so I have no comparisons. Is Hydractive as good as it should be? Does Sport mode make cornering better? Is Activa as brilliant in practice and as comfortable as non-Activa?

Please discuss at length!! Cheers,

AndersDK · Post by **AndersDK** » 20 Sep 2006, 09:19

You write hydractive/activa like you dont really know the difference ?

An activa model has the active antiroll bar system as an ADD-ON to the existing hydractive supension. Its single purpose is to minimise bodyroll when cornering - which it does very well.

The hydractive suspension is very different from the "standard" Citroen hydraulic suspension.
Firtsly it adds an extra rigidity sphere to each axle. This in turn calls for extra components to control the rigidity. The components are different from the standard - as the hydractive block is connected with 10mm piping to the suspension cylinders.

Honestly I'd say such a project is for the hardcore car-DIY badgelor only.

Its not just like lowering an Escrot project

Mandrake · Post by **Mandrake** » 20 Sep 2006, 10:22

This has been discussed at length before, not too long ago.

Although in principle the Activa is "just" Hydractive 2 with the addition of the anti-roll rams and roll corrector etc, in practice there are a LOT of implementation differences which make it impossible to just "add" the missing Activa components.

Just to list SOME of the differences:

* Although the Activa ECU is almost the same as the Hydractive 2 one, it has an extra output to control the "sc/car regulator" electrovalve, and uses different lookup tables to match the mechanical characteristics of the Activa - so a new ECU required as they cannot be reprogrammed. (A factory replacement unit can only be programmed once, as well)

* The rear anti-roll bar is TOTALLY different and in different locations between Activa and non-activa models, to allow for attachment of the anti-roll ram. Most likely the rear suspension chassis is drastically different to allow for that. (Judging by the diagrams I have) It may not even be possible to fit this within the shape of the estate body shell.

* Large gauge piping (10mm) running from the front to the back of the car as part of the sc/car regulator circuit joining front and rear rams.

* Mounting points for the roll corrector and the guides for the linkages which connect to the lower front arms will be absent.

* Numerous detail differences in things like ground clearance, castor and camber etc in nearly every aspect to do with suspension geometry the figures for the Activa are different to all other models.

You would have an easier time converting an Activa to an Estate than converting an Estate to an Activa - honest.....

Basically, forget it.

Regards,
Simon

andmcit · Post by **andmcit** » 20 Sep 2006, 10:40

I agree entirely with Simon - I think it'd be easier to get hold of an Activa for
£5 on ebay and chop the back end off and weld an estate one on instead...

I've got an absolutely MINT estate bodyshell with duff front chassis legs if
anyone wants the shell or chunks off it!

I genuinely seriuosly thought about making a trailer to match my estate
which is the same spec/colour etc but can't face the hassle of putting a
bulkhead on the chopped front...

Forget diesel - LPG it - it'll be cheaper in the long run than faffing about with
the usual diesel hassles and growing pains!

Andrew

davek-uk · Post by **davek-uk** » 20 Sep 2006, 11:03

Simon, that was just what I was hoping for (I didn’t find anything on search!?) I know there are a lot of differences between the systems and their set-ups and I was looking for feasibility. Many of the points I knew, many I suspected. Good concise answer.

With that idea out of the window, how much better is Hydractive II over my base suspension? I'm trying to assess whether it's worth swapping my good, reliable LX for an unknown VSX/Exclusive to improve ride and handling.

Kitch · Post by **Kitch** » 20 Sep 2006, 11:45

In my experience, HA models ride much better than non HA ones. I actually prefered the ride in my Activa to the SX TD I replaced it with. If you want an upgrade, look at 2.1TD's and 2.0CT estates. They have HA and the gearbox they use is 100 times better than the BE version you will have. Its like driving a different car. I noticed such a difference in quality between the Activa and the SX.

np · Post by np » 20 Sep 2006, 11:57

Davek-uk,i`ll be selling my VSX H/Active estate soon with all the toys on it

handyman · Post by **handyman** » 21 Sep 2006, 00:55

Hi Davekuk, there is an Activa estate somewhere in the UK, RHD as well, but I do not know too much about it. Malcolm, of M & C Lockwoods told me he spotted it in the garage next to his spares emporium in Bradford. The view was that it might have been a factory special, not a DIY job as the standard of engineering was near the mark. Quite possible for Citroen considering all the Auto-Cross specials that have been made by the works.
It is possible to undertake the conversion, as it is on my projects list, but not for the faint-hearted or those short of cash.
IKBA, Handyman

KP · Post by KP » 21 Sep 2006, 01:02

There was also a 2.1.td estate 4x4 version made but im sure numbers were like 1 or 2 and LHD only

If you get a ncie 1.9td with bosch pump why not run it on veggie oil as parts are cheap enough now and you dont have to modify that much really.
No activa on LPG can beat it. 45mpg, lots of torque and 43p/litre