I have a 1994 2.0i Petrol Xantia SX. Now that i have changed quite a lot i find the suspention very smooth, esspecially on motorways.
On saturday i had a quick go of a 1997 1.9TD Xantia Estate LX.
OMG How different was the ride. The 1997 Xantia seemed really soft, extreamly soft, and when you pressed the breaks and came to a stop it seemed to jerk a lot more forward than my Xantia does. This 97 Xantia seemed to take the bumps a lot better.
Now i have newish spheres on my Xantia, have tested them by pushing down and they are not flat.
How can the ride be so different between the 2 cars?
2 Xantias yet so different.
Moderator: RichardW
The spheres on the 1994/95 models are different from those on the later Xantias. The pressure in the spheres of a non-hydractive Xantia 1994 is 70/40 bars (front rear), the 1996- had 55/30 bars. The pressure in the spheres of the hydractive Xantias are different, but also higher in the 1994/95 models than in the 1996- models.
So normally a 1994 Xantia should be much softer than a 1997 Xantia. Your 2.0i should be a hydractive Xantia (3 spheres per axle). Might be that there's something wrong with the hydractive system of your 1994, so it's always running in "hard" mode.
So normally a 1994 Xantia should be much softer than a 1997 Xantia. Your 2.0i should be a hydractive Xantia (3 spheres per axle). Might be that there's something wrong with the hydractive system of your 1994, so it's always running in "hard" mode.
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<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by BX-Basis</i>
Your 2.0i should be a hydractive Xantia (3 spheres per axle). M
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SX models did not have hydractive. Not in the UK anyway.
Hydractive was fitted to VSX and Exclusive models only (OK, the Activa as well but that's being nitpicky).
Your 2.0i should be a hydractive Xantia (3 spheres per axle). M
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
SX models did not have hydractive. Not in the UK anyway.
Hydractive was fitted to VSX and Exclusive models only (OK, the Activa as well but that's being nitpicky).
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by BX-Basis</i>
The spheres on the 1994/95 models are different from those on the later Xantias. The pressure in the spheres of a non-hydractive Xantia 1994 is 70/40 bars (front rear), the 1996- had 55/30 bars. The pressure in the spheres of the hydractive Xantias are different, but also higher in the 1994/95 models than in the 1996- models.
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Are you sure about that ? I was under the impression it was based on the model not the year. See:
http://www.gsfcarparts.com/downloads/sphere_table.pdf
It implies that the 1.6 and 1.8 litre petrol and 1.9 litre disel models had the higher pressures that you mention (75/40) while the 2.0 litre petrol and 1.9 litre turbo diesel had the lower pressures (55/30)
Just recently my Dad picked up a cheap 1994 2.0i Xantia with flat rear spheres and we duly ordered some, but were supplied with 40 bar versions. Not being that familiar with the Xantia (but very familiar with earlier Citroens) were weren't any the wiser until we went to fit them and discovered that the original spheres were 30 bars.
We decided to try them anyway, but after a few days driving decided that they were simply too lively. Yes the ride was very soft, but the handling was terrible, with lots of roll and an overactive tail happy rear end at high speeds.
Even moderate acceleration would compress the rear suspension right down it was so soft, so prolonged acceleration (it's an automatic) would cause the height corrector to try to correct the height while driving, only to have the back lift when throttling off and have it correct the other way. [}:)]
Damping was less than optimal.
Thanks to the URL I posted above we were able to confirm that 30 bars were correct, and convince the supplier they had made a mistake. (Which they finally agreed and supplied another pair that were 30 bars)
What a difference! The ride still seems very soft, but it is no longer floaty. The back end is well controlled and well damped, with no overshoot at all. Roll is less, and the compression of the rear suspension under acceleration has gone from rediculous amounts to a minor annoyance. (It is there in all hydropneumatic citroen's to some extent, but the Xantia with the 40 bar spheres was the worst I've ever come across)
It seems to me that 40 bars at the back of a Xantia is simply too soft, I can't understand why the lower spec models like the 1.6 are so soft like this... maybe they think that because the engine is slightly smaller people wont drive them fast and therefore wont notice the poor handling ? [:p]
Regards,
Simon
The spheres on the 1994/95 models are different from those on the later Xantias. The pressure in the spheres of a non-hydractive Xantia 1994 is 70/40 bars (front rear), the 1996- had 55/30 bars. The pressure in the spheres of the hydractive Xantias are different, but also higher in the 1994/95 models than in the 1996- models.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Are you sure about that ? I was under the impression it was based on the model not the year. See:
http://www.gsfcarparts.com/downloads/sphere_table.pdf
It implies that the 1.6 and 1.8 litre petrol and 1.9 litre disel models had the higher pressures that you mention (75/40) while the 2.0 litre petrol and 1.9 litre turbo diesel had the lower pressures (55/30)
Just recently my Dad picked up a cheap 1994 2.0i Xantia with flat rear spheres and we duly ordered some, but were supplied with 40 bar versions. Not being that familiar with the Xantia (but very familiar with earlier Citroens) were weren't any the wiser until we went to fit them and discovered that the original spheres were 30 bars.
We decided to try them anyway, but after a few days driving decided that they were simply too lively. Yes the ride was very soft, but the handling was terrible, with lots of roll and an overactive tail happy rear end at high speeds.
Even moderate acceleration would compress the rear suspension right down it was so soft, so prolonged acceleration (it's an automatic) would cause the height corrector to try to correct the height while driving, only to have the back lift when throttling off and have it correct the other way. [}:)]
Damping was less than optimal.
Thanks to the URL I posted above we were able to confirm that 30 bars were correct, and convince the supplier they had made a mistake. (Which they finally agreed and supplied another pair that were 30 bars)
What a difference! The ride still seems very soft, but it is no longer floaty. The back end is well controlled and well damped, with no overshoot at all. Roll is less, and the compression of the rear suspension under acceleration has gone from rediculous amounts to a minor annoyance. (It is there in all hydropneumatic citroen's to some extent, but the Xantia with the 40 bar spheres was the worst I've ever come across)
It seems to me that 40 bars at the back of a Xantia is simply too soft, I can't understand why the lower spec models like the 1.6 are so soft like this... maybe they think that because the engine is slightly smaller people wont drive them fast and therefore wont notice the poor handling ? [:p]
Regards,
Simon
Simon -
You're right on the point that sphere type is related to model variant - not phase I or II.
But you are NOT correct on the assumption that the center bore is the damper valve. In fact the damper valve is the bits around and underneath the center bore. The calibration of this damper valve has a dramatic influence on how the car drives. Like having a shocker or not.
You're right on the point that sphere type is related to model variant - not phase I or II.
But you are NOT correct on the assumption that the center bore is the damper valve. In fact the damper valve is the bits around and underneath the center bore. The calibration of this damper valve has a dramatic influence on how the car drives. Like having a shocker or not.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by AndersDK</i>
Simon -
You're right on the point that sphere type is related to model variant - not phase I or II.
But you are NOT correct on the assumption that the center bore is the damper valve. In fact the damper valve is the bits around and underneath the center bore. The calibration of this damper valve has a dramatic influence on how the car drives. Like having a shocker or not.
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Hi Anders,
Where did I say the centre bypass hole was the entire damper valve ? In fact I didn't even mention it at all in this thread. (I did mention the bypass hole bore size in another thread however)
(Edit: Ah, maybe you misinterpreted my 1.6 reference to being the bypass hole diameter ? In fact I was refering to the 1.6 litre model that has the 40 bar spheres fitted as standard....)
I'm well aware of the other slanted holes under the washers and how the valve as a whole works, as I have reconditioned and tweaked the old removable DS sphere damper valves before.
Spheres for different models of car altogether probably do have different washer parameters (thickness etc) but unfortunately on modern spheres, they are not easily replacable.
This leaves the bypass hole as the only thing you can easily alter. The bypass hole still has a dramatic effect on the rebound action of the car.
The reason being that the washers are usually calibrated so that they open the main ports under normal travel over bumps, but are slightly too stiff to open in response to the suspension rebound, leaving the bypass hole as the only way for the rebound to be completed.
Imagine driving along a flat road and hitting a 2 inch step in the road. The sudden shock easily opens the washer valves to allow the bump to be absorbed, and then they close. When the gas pressure tries to rebound the suspension height to the normal height, the gas pressure and washer stiffness are such that the rebound force can't quite open the reverse valve, and it must leak through the bypass hole.
If the washers are fairly firm, the bypass hole bore will have a dramatic effect on the damping and ride. If the washers are fairly soft it may only have a minor effect.
A few years ago we got some new front spheres for my Dad's CX2400, and we were unhappy with the damping. There was obvious float on the rebound which was quite unsettling.
The standard bypass hole for those spheres was 1.9mm and we experimented with sizes from about 1.2mm up. We finally settled on 1.5mm which completely eliminated the sensation of float, improved the cornering and handling noticably, while still giving good ride. 1.2mm was a bit too firm, and made the ride a little bit more rumbly and made the car drop into manhole dips instead of absorbing them.
Yet on another pair of CX spheres (the original regassed ones) changing the bypass bore didn't make a lot of difference. Obviously the washer parameters were either different (thiner/softer washers) or the washers were worn with age.
No, the bypass hole bore is not the entire damper valve, but it is a very important part of the overall damper unit.
Regards,
Simon
Simon -
You're right on the point that sphere type is related to model variant - not phase I or II.
But you are NOT correct on the assumption that the center bore is the damper valve. In fact the damper valve is the bits around and underneath the center bore. The calibration of this damper valve has a dramatic influence on how the car drives. Like having a shocker or not.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Hi Anders,
Where did I say the centre bypass hole was the entire damper valve ? In fact I didn't even mention it at all in this thread. (I did mention the bypass hole bore size in another thread however)
(Edit: Ah, maybe you misinterpreted my 1.6 reference to being the bypass hole diameter ? In fact I was refering to the 1.6 litre model that has the 40 bar spheres fitted as standard....)
I'm well aware of the other slanted holes under the washers and how the valve as a whole works, as I have reconditioned and tweaked the old removable DS sphere damper valves before.
Spheres for different models of car altogether probably do have different washer parameters (thickness etc) but unfortunately on modern spheres, they are not easily replacable.
This leaves the bypass hole as the only thing you can easily alter. The bypass hole still has a dramatic effect on the rebound action of the car.
The reason being that the washers are usually calibrated so that they open the main ports under normal travel over bumps, but are slightly too stiff to open in response to the suspension rebound, leaving the bypass hole as the only way for the rebound to be completed.
Imagine driving along a flat road and hitting a 2 inch step in the road. The sudden shock easily opens the washer valves to allow the bump to be absorbed, and then they close. When the gas pressure tries to rebound the suspension height to the normal height, the gas pressure and washer stiffness are such that the rebound force can't quite open the reverse valve, and it must leak through the bypass hole.
If the washers are fairly firm, the bypass hole bore will have a dramatic effect on the damping and ride. If the washers are fairly soft it may only have a minor effect.
A few years ago we got some new front spheres for my Dad's CX2400, and we were unhappy with the damping. There was obvious float on the rebound which was quite unsettling.
The standard bypass hole for those spheres was 1.9mm and we experimented with sizes from about 1.2mm up. We finally settled on 1.5mm which completely eliminated the sensation of float, improved the cornering and handling noticably, while still giving good ride. 1.2mm was a bit too firm, and made the ride a little bit more rumbly and made the car drop into manhole dips instead of absorbing them.
Yet on another pair of CX spheres (the original regassed ones) changing the bypass bore didn't make a lot of difference. Obviously the washer parameters were either different (thiner/softer washers) or the washers were worn with age.
No, the bypass hole bore is not the entire damper valve, but it is a very important part of the overall damper unit.
Regards,
Simon