ZX handling mods

__CA__ · Post by **__CA__** » 22 Feb 2006, 22:02

Over the last few months I've been experimenting (and spending far too much money

) with the handling of my ZX 16v. I just thought I would share my findings with you.

Warning - not everyone is going to approve of treating a Citroen like this, but to me it's just a car, not a work of art that needs to be preserved.

So far I've added...

PeugeotSport Group N balljoints:

PeugeotSport Group N P-bushes:

PeugeotSport Group N front bushes:

A thicker rear anti-roll bar (25.4mm instead of 24mm standard) (no photo, but it's basically a big metal bar with splines either end

)

Solid rear beam mounts - no rubber at all (from Skip Brown):

PeugeotSport Group N engine mounts:

I've also ditched the rear seats, the carpets, the under-carpet soundproofing and the rear trim:

The springs and dampers are still standard, 10 year old items, but the car has only done 55k miles so they're still in good condition. And with less weight to control, the springs and dampers are effectively stiffened anyway.

So what does all this do? It makes it handle like an absolute dream. The steering in particular is really good now, it turns in with precision and poise. In extremis, it will still understeer safely, but lifting off either provokes the inside rear wheel to cock in the air as the speed washes off and it tightens its line, or if you're going faster (or the road is wet), it will drift into oversteer smoothly and predictably. A lot of the lateral 'sproing' and rubberiness has disappeared, so it slides and recovers quite naturally now with no lurching or tank-slapping.

Yes, it's noisier, and yes, it vibrates and hums like a rally car thanks to the engine mounts, but they've eradicated the driveline shunt and made gearchanging a much slicker affair.

My top recommendations would be the front end bushes, and particularly the balljoints. They add a bit more negative camber, so turn-in and steering feel is improved. The stiffer bushes really help to locate the lower arms properly, but they're not at all uncomfortable. These parts aren't that expensive either (£50 for the pair of balljoints, £50 for the 2 P-bushes, £70 for the 4 front bushes). OK, so that's crazy money compared to GSF, but these bits are really worth it! 8)

If anyone's interested in buying a VGC black leather interior and 24mm rear anti roll bar, let me know

rossnunn · Post by **rossnunn** » 22 Feb 2006, 22:09

Good post, interesting read. Are you going to lower it too?

__CA__ · Post by **__CA__** » 23 Feb 2006, 20:06

Longer-term I might do, but only by a little. It sits pretty low as standard tbh. I'd rather keep as much suspension travel as possible for road driving rather than lowering just because it looks good.

It could do with slightly stiffer front springs to finish it off really (although it's not at all bad as it is). Coilovers on the front would allow me to adjust the ride height precisely, and then I can drop the rear to suit. Some quality dampers would also be nice but I've spent enough for now!

rossnunn · Post by **rossnunn** » 23 Feb 2006, 23:54

I ask as I have a set of standard front struts & lowered springs that will be coming up for sale soon.
I can only say how impresed I am with it, yes over some bumps its abit jiggerly but if feels like a standard setup , just lower. Reason for change? I bought some spax shocks & spings that I'm going to be putting on.

oscarloco · Post by **oscarloco** » 24 Feb 2006, 23:02

You have done what I've always dreamed of doing to my car! Good luck pal, hope you enjoy driving the wheels off your car as much as I do

ci_newman · Post by **ci_newman** » 26 Feb 2006, 09:56

OO, looks like it'll be a nice little runner around a track..

Im more interested in your Black leather interior though... Im desperately looking for one, but cant find any for love nor money

rossnunn · Post by **rossnunn** » 26 Feb 2006, 11:41

*cough*eBay*cough**cough*

Toddman · Post by **Toddman** » 28 Feb 2006, 10:51

Interesting read

I could be way off here but years ago when messing around with Volcanes I was lead to beleive that fitting solid rear beam mounts ruined the passive rear wheel steering which was what made the ZX shine over the 306 - most motorsport people said stiffen up the front with pug parts but keep the rear wheel steer.

Just curious as to what you think?

Cheers
Luke

rossnunn · Post by **rossnunn** » 28 Feb 2006, 12:17

I thought the 306 also used the same steering rear end?

Toddman · Post by **Toddman** » 28 Feb 2006, 12:31

AFAIK only the GTi-6 used it.

Cheers
Luke

Village · Post by **Village** » 28 Feb 2006, 13:52

Im more interested in your Black leather interior though

*cough*eBay*cough**cough*

FYI its from a 5 door, not sure if that makes any difference. Except if you have a three door and need to get people into the back seats (no tilt mechanism on 5 door seats)

rossnunn · Post by **rossnunn** » 28 Feb 2006, 15:06

yeh the front seat runners are different too, the outer runner is turned 90 degrees on a 3 door & bolts to the inner sill area.

__CA__ · Post by **__CA__** » 28 Feb 2006, 19:17

306s and ZX have identical rear beams, and mounts. The whole 'passive rear steer' thing I have my doubts about really, I sense marketing spin at work

All I know is that with these mods:
- it's easier to judge how hard I'm working the outside rear tyre
- it oversteers more predictably, and only when asked to (so far

)

It may prove a little too tail happy on the track, or in extreme conditions on the road (e.g. when having to slow down in a hurry mid-bend because of something in the road). If that's the case then stiffening the front end should bring the balance back to being more neutral.

Toddman · Post by **Toddman** » 28 Feb 2006, 21:50

Thanks for th efeedback

Interesting what you say about the mounts being the same I have always been told the ZX is different to the normal 306 but I have never looked into it.
Cheers
Luke

rossnunn · Post by **rossnunn** » 01 Mar 2006, 00:09

yeh it did get me thinking, Zx's certanly the same as 306 D Turbos. I think the passve rear steering is just that it allows a few mm of movement sideways, nothing huge.
I wondered if it wasn't a intentional thing when they designed it. I'm wondering if the ear arms actually twist very slightly during hard cornering & rather saying they have a problem, becuase nothing's going to break they called it a feature. I've not just thought of a way to test the rear beam to see if it actually does 'steer'.