Thirsty V6 Xantia

[Mandrake]

I should have probably mentioned - with the Hydractive 2 system if the hydractive regulator (centre) spheres are fully gassed and in good order but the strut (corner) spheres are very low in gas (half pressure or less) it will tend to make the ride a bit wallowy in the soft mode upon hitting large bumps or undulations.

This is because normally small bumps and undulations are absorbed by the regulator sphere in the centre (most of the oil displacement from a gradual movement flows into the centre sphere because the strut sphere dampers have a high opening threshold while the centre damper valves have a low threshold) while large bumps are absorbed mainly by the strut spheres. (Once the damper valve thresholds in the strut spheres are exceeded there is more gas volume in the two strut spheres combined than the centre on its own, so a larger percentage of the oil flows into the strut spheres)

As the centre damper valves are fairly soft and the strut sphere damper valves are very stiff this means that the rebound rate for small movements is soft, (as the oil is mainly returning from the centre) but for large movements is heavily damped. (As the oil is mainly returning from the strut spheres)

However if the strut spheres are quite low in gas it forces the centre regulator sphere to provide most of the springing for the car, (in soft mode at least) and as the centre sphere has soft damper valves this means the car becomes underdamped for large movements.

At the same time the hard mode will become stiffer when the strut spheres are low in gas because they then become the only springing element.

So even if the correct spec spheres are fitted if the strut spheres are low in gas you will get a ride that tends to be wallowy with large movements while in soft mode, but excessively stiff in hard mode. (The change in springing/damping between the two modes becomes exaggerated)

In Hydractive 2 the balance in sphere conditions between centre regulator sphere and strut spheres is quite important.

[Ozzie Kuma]

addo, spheres, see Jason H, very reasonable price / sphere, I think he has a friend with a regassing unit that he "books" . He did the VSX & its great.

Mandrake, HISTORY.. jeez... I thought I had a good history from the sales pitch the "original" owner gave me , & together with the mountain of paper work... BUT !!! not all was as it seems.
I really do not think I have much of a "problem" with the spheres, it is just me wanting the V6 to ride like the VSX. Bothe are really very good in their own way, if you drove one & not the other , I would be happy, but when I get out of the VSX & into the V6 , I think ," how can I get the engine in here....
..... so comfort spheres, !! I have seen them mentioned in the forum but do not really understand,.. I assume they are "standard" spheres with more (?) pressure or are they special spheres? I do not think that is the case, the original owner did not seem that into the ride of the car. I shall mention it to the regasser, he is pretty good on such things.
Another side issue , would you agree that the V6 front fenders are wider than the VSX ? I have had people say the car has been in an acco, pointing to the fenders but I have been DEEP into the front of the car & I very very much doubt the acco. I figure that Citroen just needed more room for the V6.

[addo]

The gassing rig is property of CCCNSW. I just don't like the way they approach some things, and a good whack of it is elephant in the room territory.

I want to do mine with the Italian system, so once they're configured I can repressurise or adjust without removal from the car. Unfortunately, as Robert Smart pointed out, they are slow to respond if you're not an Italian speaker!

[xantia_v6]

Another side issue , would you agree that the V6 front fenders are wider than the VSX ? I have had people say the car has been in an acco, pointing to the fenders but I have been DEEP into the front of the car & I very very much doubt the acco. I figure that Citroën just needed more room for the V6.

All Mk2 Xantias (regardless of engine) have the wide front end, as do Mk1 cars with BE5 or 4HP20 transmissions (meaning V6, 2.1TD and 2.0TCT engines).

[Mandrake]

Mandrake, HISTORY.. jeez... I thought I had a good history from the sales pitch the "original" owner gave me , & together with the mountain of paper work... BUT !!! not all was as it seems.
I really do not think I have much of a "problem" with the spheres, it is just me wanting the V6 to ride like the VSX. Bothe are really very good in their own way, if you drove one & not the other , I would be happy, but when I get out of the VSX & into the V6 , I think ," how can I get the engine in here....

As I say, the more I'm driving my V6 with new spheres, the more the ride and handling feels like my old VSX. They're not identical but given they're different cars (even Citroen's of the exact same model tend to ride differently from one to another...) they're pretty close. I would say the ride at the rear is identical and the ride at the front is slightly stiffer on the V6 than the VSX but the overall feel is very close, so I don't think there is any fundamental difference in the ride between a Hydactive 2 VSX and a Hydractive 2 V6 - its all just down to individual differences in the cars like the condition of the spheres, rubber bushings, balljoints, tyres etc...

..... so comfort spheres, !! I have seen them mentioned in the forum but do not really understand,.. I assume they are "standard" spheres with more (?) pressure or are they special spheres? I do not think that is the case, the original owner did not seem that into the ride of the car. I shall mention it to the regasser, he is pretty good on such things.

"Comfort" spheres are aftermarket strut spheres which have softer damper valves by way of drilling out the centre bypass hole slightly. (Which is the predominate controlling factor for the rebound control) They're available from the likes of AEP and GSF as an alternative to the standard spec spheres. I think they are available in Aus/NZ, but not through Citroen themselves.

Some people like them but I would stay away from them as I think their whole raison d'être is flawed. The idea is that the damping in the hard mode is quite stiff on a Hydractive 2 system, so a comfort sphere makes the hard mode a bit softer, however this upsets the balance in soft mode making the soft mode a bit wallowy and floaty. To do it properly the damping would need to be increased on the hydractive regulator unit to prevent the soft mode from becoming too wallowy. If the car does have comfort spheres fitted it would explain the difference in feel you notice.

Are you able to quote us the part numbers on the spheres ? From that we can look them up and find out what spec they are.

As I said earlier, the other possible reasons for the ride being a bit wallowy (other than comfort spheres) is that the wrong spheres are fitted entirely (from a slightly different model or model spec) or the strut spheres are low in gas.

With correct, in good condition spheres, the ride and handling should be very similar between the two cars...

[CitroJim]

Simon, one subtle difference on the V6 that might make it ride just a little firmer than a smaller VSX is the front struts; they are larger diameter and unique to the V6. As are the strut tops...

I find my V6 is firm somewhere between the HDi (which is really quite squisy) and the Activa which is by design quite taut. I like it as I find the HDi a bit too squishy at times and she has a tendency to bottom out at the rear but that might be because I have estate rear spheres fitted.

I like the feel of my V6. Taut and well damped but it has to be said they're not quite the magic carpet the smaller-engined hydractives are.

I do understand that when they were first released some were surprised to find the V6 was not quite as floaty as they expected such a luxury car to be. Really it's quite sporty and as I say, edging toward Activa territory...

[DickieG]

I like it as I find the HDi a bit too squishy at times and she has a tendency to bottom out at the rear but that might be because I have estate rear spheres fitted.

Are the rear bump stops in good condition as they form an important role in slowing down the compression rate.

[CitroJim]

I like it as I find the HDi a bit too squishy at times and she has a tendency to bottom out at the rear but that might be because I have estate rear spheres fitted.

Are the rear bump stops in good condition as they form an important role in slowing down the compression rate.

Nope, almost non-existent

I have some spares I really must fit Might get round to dong that today...

[CitroJim]

Popped the new bump stops on Rattiva II today... Very easy job

Here was one of the old ones...



Compared to a new one...



What a difference it makes!!!!!

[Ozzie Kuma]

hey addo, did you ever get the bump stops we were tic tacing about last year? Looks like something I should do.

[Ozzie Kuma]

Are you able to quote us the part numbers on the spheres ? From that we can look them up and find out what spec they are.

Not real sure what the part number is, but I assume it is these..
drivers rear corner

off rear corner

rear centre


Front centre


Front off corner



Couldn't get to / see numbers on the rest.. What should that tell me...??

[addo]

A lot of yours are aftermarket (Lizarte, mostly per the bird logo). Front struts spheres look original; manufacturing date 175th day 1998 ("8-175").

[Ozzie Kuma]

so what does that mean? aftermarket is OK? / not OK? short life / prone to ????

[addo]

It means I have no valid opinion! My only aftermarket sphere was a flawed item and it would be stupid to generalise on just one experience.

The only fair point to observe, is that the spheres were changed because either:
Someone had no idea about gassing them up, or
The car had been neglected so long they were not deemed salvageable (pressures below 10 Bar)

[Ozzie Kuma]

OK,... (?)
So, originals are "better", is there a big price difference ? & what do you get for the price diff.?

I guess none of these are "comfort" spheres, or isn't it that easy to tell.?

re what is stamped on them,..I can guess what the date & 30 bar bits means, what does the other bits mean.....
FM
XT
Activ
AC/XM ( XM accumulator?)