Activa Rams

[addo]

OK, please bear in mind all my "knowledge" on these has been gained by poring over website images! I have found someone here with an XII Activa but we are both pretty busy characters and they're not a really hands-on type.

It appears the rear suspension additives all mount to standard trailing arms (by part number) but use some extra holes in the subframe (is it stiffened there?). On the front, at least the strut base to which the ram is attached, is different to non Activa - is the opposing side different to stock?

Also it seems the lower front arms may have a different part number - is it a larger pivot bearing/bushing to account for extra stresses?

If (run for cover now!) one were to fit the Activa antiroll bars and so forth to a vehicle and not (yet) integrate the system could the rams simply be filled with fluid and capped off, to create more or less rigid links? I assume they're bidirectional in function, like the PAS ram.

Would the rear ram top, hit an estate boot floor?

Thanks, Adam.


p.s. I see the Activa ECU (as opposed to the Hydractive II) is now "NFP".

[handyman]

Hello Adam, almost all the suspension parts on the Activa are different to the stock vehicles, whether fitted with Hydractive or not. If you imagine the extra forces the suspension has to deal with on cornering, Citroen has beefed up all the components to cope.

I cannot see any advantage in adding the anti-roll bars and Activa rams to a standard car, as it is the two way action of the ram that controls the car's attitude as it turns around bends and stops the car rolling. The ram has to not only stiffen up the ride to stop roll on the outer side of the car, but also has to be flexible to allow movement of the suspension. That's the nice thing about the system that even on bends with uneven road surfaces, the inducement to roll is countered but the suspension never gets choppy due to over-damping, so road contact is always maintained.

In addition, the body shell has been stiffened to cope with the extra forces generated by the Activa suspension.

After a number of years building amateur rally cars, using conventional spring and damper systems, I am always amazed that other manufacturers, along with Citroen in the C3 and C4 rally cars, has never utilized or developed the Activa system. I just think they are all a little blinkered.

What's the point in going fast round a corner on three wheels when it can be done effectively and safer on four?

What about a bumper sticker " I do it on all fours!"?

Handyman

[addo]

Sorry Handyman, my methodology was probably explained not-so-well.

I use the car more often than not, it being a convenient (useful) size for work gear and comfy to travel in. Excessive downtime isn't really an option, so I was looking at "staging" upgrades to Activa status. I've got plenty of credit for hoist time at a mate's workshop and can grab his staff as required for two man work.

Hence the locked rams would only be a transient measure, say for a week or two. My impression of what people refer to as "defaulting to the hard mode" suggests the rams are inactive in this form, and thus equate to the above proposal. Maybe this is mis-assumed?

As to the bodyshell - I know the V6 cars had extra underfloor bracing against reactive torque and a couple of different forward members to allow extra clearance or bracketry, but looking at the saloon shells there is no specific Activa shell:

5 DOOR SALOON AND RIGHT HAND DRIVE
A : FOR VEHICLE TO 00007853 SEE NOTE "STRUCTUR BV"
B : FOR VEHICLE FROM 8281 WITH HYDRACTIVE SUSPENSION ORDER POSSIBLY 527612 + 4 X 6922E0 + 4 X 694171 +2 X 6936A0

Not having any luck at present back-tracing those auxiliary part numbers. My RPO is 08150-ish from memory.

Comparing the guts of Hydractive II and Activa there's a lot of overlap; enough to make pillaging an HII car worthwhile. I suspect the local delivery harness for Hydractive II also has the Activa plugs in it.

Overall, I know the experience won't be "plug and play" but even if it doesn't work out I can go back to a Hydractive estate; surely that's better than stock!

Regards, Adam.

[handyman]

Hello Adam. I see what you are trying to do, but as I had said on another thread, the amount of gear that has to be stripped out and replaced would mean the car would have to be off the road whilst undertaking the work. I donot think it will be "plug and play" for want of a better expression and as you are fitting a whole system, it cannot be done on an ad-hoc basis.

Personally, I would get the donor and recipient side-by-side on stands and strip out and replace complete assemblies. At least this way you stand half a chance of getting everything fitted where it belongs and having the time to modify the recipient should you find the bodywork needs modification.

As for bodyshell differences, I am only relaying what I had been told by my friend in France who owns a Citroen dealership and has modified a number of Xantias, when they were current models, primarily for French AutoCross racing.

Handyman