Xantia Activa Strut Spheres

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
KevMayer
Posts: 1051
Joined: 12 Sep 2003, 22:01
Location: Staffordshire, United Kingdom
My Cars:
x 2

Xantia Activa Strut Spheres

Post by KevMayer »

I called GSF today at their Birmingham main branch to ask if they stocked front strut spheres for an Activa. Part number N45335 used to be stocked for this purpose.

The lady on the phone was very helpfull and searched her information for some time.

She couldn't find any reference in her present databases, but, she reverted to an older system and found a reference to N45334.

The note said that N45334 were now the ones to offer for Activa front spheres.

Now, N45334 are the spheres listed for the front of a Hydractive Xantia and their volume, pressure and jet is very similar to the Activa units.

N45335 450/45/0.7 - Activa (or in another listing shown as 400/45)

N45334 400/50/0.6 - normal Hydractive

It looks to me like the Hydractive spheres will be a firmer ride because of the higher pressure and more restricted jet but, they don't look a million miles away and would probably be ok.

I was tempted to buy 2 x N45334, but thought I'd seek the opinion of the forum first.

Cheers, kev
Cheers, Kev

02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).

Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
User avatar
CitroJim
A very naughty boy
Posts: 49526
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Post by CitroJim »

Hi Kev,

As these spheres are only fully effective when the suspension is switched into hard mode, which is not for very long normally and then only when driving with enthusiasm, I don't think it'll make a fantastic amount of difference. It's the hydractive centre sphere that does the lion's share of the work in normal driving.

In fact, I think the extra 5 bars in them will actually make them a tad softer if anything and the 0.6 hole will improve the damping a tad and in an Activa, that's no bad thing.

If nothing else, it'll be an interesting experiment..
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Post by Mandrake »

I agree with Jim - the strut spheres on the Hydractive 2 and Activa are very close in spec - I'm not even sure why they bothered to make them slightly different - when the Activa spheres actually have slightly LESS damping.

I have a pair of Activa rear strut spheres on my HA2 Xantia (as it was all I could get at the time) and they work fine, the ride is actually a bit softer than the standard spheres but still well enough damped, and it certainly makes the hard mode a bit more pleasant.

As for the pressure difference - there is no difference between those two combinations because the sphere volume is different as well -

50 bars in a 400cc sphere has almost identical spring rate to 45 bars in a 450cc sphere, because if you do the math, the SAME precharge pressure in a LARGER volume sphere gives a softer springing rate, therefore the gas pressure is reduced by the same percentage to get the same springing rate.

The advantage of the bigger sphere is that it gives better linearity over a wider range of loads. The disadvantage is it takes more oil input to reach operating pressure, therefore takes longer to lift. (Not really an issue on Anti-sink)

My HA2 Xantia actually has 450cc 45 bar spheres, Citroen original, but 400cc at 50 bars was also another one of the valid configurations depending on the market and year.

Generally the long life multilayer front spheres were 450cc, while the standard single layer diaphram spheres were 400cc.

Regards,
Simon
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
Post Reply