C6 video

406 V6 · Post by **406 V6** » 01 Jun 2005, 16:56

BMW, a car that leans on turns doesn't necessarily mean it's dangerous[;)]
The venerable DS leaned a lot on a curve, but it's handling wouldould equal many sports cars of the time and even surpass them.

Kowalski · Post by **Kowalski** » 01 Jun 2005, 17:34

I'd agree with what 406 V6 says above.
Body roll isn't a problem in itself, as long as the suspension geometry can keep the tyres in contact with the road. Its where the suspension geometry can't keep the tyres nicely contacting the road surface, i.e. where they distort and you end up running on shoulders and sidewalls that its a problem. If you've got good suspension design and suitable tyres body roll is no problem whatsoever.
One of my colleagues has a BMW 330d, and he says he feels unsafe in my Xantia, he doesn't like the way it floats over bumps mid corner. Personally, I don't like the way his car crashes over bumps mid corner...

Mandrake · Post by **Mandrake** » 02 Jun 2005, 04:40

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Kowalski

I think Mr Clarkson had said that air suspension ruined the ride of several cars that had it (Jaguar Mercedes etc) and steel was the way to go for comfort. Obviously he hasn't heard about Citroens...
<hr height="1" noshade id="quote"></blockquote id="quote">
On the contrary, he's forever slagging them off if you watch Topgear regularly. Even though I find topgear amusing to watch most times, it does bug me the unnecessary jabs they keep giving at Citroen, mainly from Clarkson...
Regards,
Simon

Mandrake · Post by **Mandrake** » 02 Jun 2005, 04:50

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Kowalski

It's a double wishbone setup, which is definately better than machpherson struts and trailing arms.
<hr height="1" noshade id="quote"></blockquote id="quote">
Whats so wrong with trailing arms at the back ? I agree that the Macpherson struts at the front of the BX/XM/Xantia don't hold a candle to proper double wishbone setups like the CX or the GS, (the latter being one of my favourite geometry designs, as they got everything almost perfect due to the brakes not being in the way...) but there is nothing wrong with trailing arms.
A lot of manufacturers seem to be of the more parts the better approach with rear suspension these days with "multi-link rear suspension" being a selling point, as if it was something good.
And yet the trailing arm is elegant in its simplicity and function. There's likely to be a reason that Citroen has used it for nearly every car they've ever built... [:D]
Regards,
Simon

adamskibx · Post by **adamskibx** » 02 Jun 2005, 08:50

The suspension systems of cars that roll a lot such as the DS are perfectly safe, but they are not as good for "sporty" driving. Yes, a car whith well designed soft suspention that keeps all tyre in contact with the road and keeps geometry etc all good will be safe and the maximum angular velocity acheivable may well more morre than that of a hard riding sporty setup, depending on the center of mass. A 2CV rolls a heck of a lot but this is down to extremely soft suspention more than height and weight distribution. This means that even under excessive roll angles, there is not necessarily that much extra downwards force on the outside wheels compared with the inside in comparison to a strongly sprung car. In other words, a softly sprung car will add to the force and demands on the outside edge tyres and there is only so much they can take, but this is not necesarily that significant depending on the weight and height of that weight in the car. In fact due to the fact that most roads are uneven, there will be an outright cornering speed advantage so long as the suspention is well designed as the tyres follow the contours of the road better. The disadvantage of a soft setup is that the car is less chuckable and tight bends one after the other will really slow you down as when you go into a corner and turn quickly, the car rolls up to a point where the suspention/roll bar stops it and this is where grip can be lost and things get messy-in a 2CV, you may well be able to take rounderbouts very quickly but a couple of tight S-bends will slow you down a lot with the momentum of previous roll direction etc.
As for BMW suspention, most of them are sporty and firm in my experience but I know the last 3 series (think theres been a new one out recently after this one) was aimed at pleasing the American market and the ride quality is staggering.A friend of mine has one as a company car- I have driven it and its almost up to GS standards. As for the C6, I reckon it will be very good and the hydractive systems will probably make it way better than the 607, even if all the other components are the same.

jeremy · Post by **jeremy** » 02 Jun 2005, 10:04

Isn't the problem with trailing arms at the rear that as the car rolls, so does the tyre tread, so with extreme roll there is considerably reduced contact pressure on the inside edge of the outside tyre. With a crossply tyre this doesn't really matter as the tyre will distort but with a radial it starts to become more important and can give sharp breakaway characteristics. If you lower the profile of the tyre it becomes even more susceptible to this problem.
A good double wishbone suspension with longer lower arms would cure the problem and allow the tyre to remain parallel with the road as does a deDion axle. Strangely this was one of the justifications for using the live axle on the Rover SD1 (and presumably its cousin the TR7)
jeremy

ACTIVE8 · Post by **ACTIVE8** » 02 Jun 2005, 16:20

That's an interesting video of the C6, the headlights also look nice.
At least their design looks better than the old Ford Granada, where the light design looked odd, and that particular model ended up with the nickname of the "fish eye" Granada.
BMW your Xantia Activa 3.0 V6 would certainly have a market value over here in the U.K. as it would be a rare car here. While as there are so many BMW's here, they don't stand out unless they are the more unusual models.
<blockquote id="quote">quote:<hr height="1" noshade id="quote">Posted by BMW
I've tried non-Activa Xantias and the suspension is really dangerous - they have wheels but on corners they balance as a boat... <hr height="1" noshade id="quote"></blockquote id="quote">
The non Activa Xantia's are good cars, and I certainly wouldn't describe them as dangerous. They offer a far more comfortable ride, than any other car in the same size, and price class.
The Xantia Activa is an inventive, intelligent, impressive design, taking the clever Citroen suspension design a stage further to enable the car to have better handling.
Question for the BX experts on the forum.
The BX had a 4 X 4 model in it's range, but prior to the Activa design on the Xantia, did Citroen try out the idea previously on a BX, as an experiment or prototype ?

406 V6 · Post by **406 V6** » 02 Jun 2005, 16:38

Nah, they tryed the activa concept on the DS[:D].