RE: PH Blog: passive / aggressive
Discussion
Did anyone else find this article oddly hard to read, it felt like it didn't really have any flow to it?
Also parts of it read like an absolutely blatant advert.
As for adaptive dampers, they are trying to create magnetorheological dampers without having to actually do the research/spend the money on it.
IIRC in this country only Audi and Ferrari have fitted them to production cars (the TT, R8, 458, 599GTB and the F12) and the road going versions are still not the full package compared to below.
To see how good 'adaptive' dampers can be, watch this and then tell me that passive dampers are still better than them and that the chassis is the be all and end all of it!
If that link doesnt work, watch this video from 5 minutes 59 seconds onwards for the actual demonstration:
Click here
Also parts of it read like an absolutely blatant advert.
As for adaptive dampers, they are trying to create magnetorheological dampers without having to actually do the research/spend the money on it.
IIRC in this country only Audi and Ferrari have fitted them to production cars (the TT, R8, 458, 599GTB and the F12) and the road going versions are still not the full package compared to below.
To see how good 'adaptive' dampers can be, watch this and then tell me that passive dampers are still better than them and that the chassis is the be all and end all of it!
If that link doesnt work, watch this video from 5 minutes 59 seconds onwards for the actual demonstration:
Click here
Edited by Silent1 on Wednesday 9th May 22:15
I have just had switchable dampers retrofitted to my DB9 by Bamford Rose. They are absolutely stunning, takes the car from standard, slightly wafting but beautifully damped Aston to firmer than sports-pack at the touch of a button.
Great to be able to switch, 99% of the time in town and motorway I am on the softer setting, when I feel like it and roads permit (or demand!) I press the button. I find I use the firmer setting more and more, and the progress I make has become far more rapid and a lot more fun. Very confidence inspiring stuff!
If you have an MX-5 or Elise, it only has one job - it's a sports car! But something big and heavy like a DB9 or an SLS, it's nice to be able to do the big wafting GT thing thing on the autoroutes and then firm-up when you hit the back roads
Great to be able to switch, 99% of the time in town and motorway I am on the softer setting, when I feel like it and roads permit (or demand!) I press the button. I find I use the firmer setting more and more, and the progress I make has become far more rapid and a lot more fun. Very confidence inspiring stuff!
If you have an MX-5 or Elise, it only has one job - it's a sports car! But something big and heavy like a DB9 or an SLS, it's nice to be able to do the big wafting GT thing thing on the autoroutes and then firm-up when you hit the back roads
Cotic said:
Palmball said:
..go from full soft to full hard numerous times a second...
I had a problem like that too. Better now though. Changed the saddle and let the tyres down a bit.
wormburner said:
These systems that gradually ease back from 'sport' to 'standard'... at what point does the 'sport' light go out?
If this was happening surely people would be heading back to dealers to say their car won't stay in sport mode?
It doesn't....the light stays on so it 'looks' like its still in sport (assuming systems actually do in fact do this). If this was happening surely people would be heading back to dealers to say their car won't stay in sport mode?
Ocellia said:
...or use the Citroen system! Never bettered!
Yes, I was thinking this. I do like the unique ride that a hydraulic Citoen gives but they don't tend to do the sport part so well (although I've never driven an Activa and always wondered what one would be like). I don't think the lack of sportiness can be layed entirely at the door of the suspension though!I wonder...could the Citroen system be capable of providing variable springing too?
I recently put Spax adjustable dampers on my old VW Beetle. After a bit of playing around I've settled on a particular setting and stuck to it.
What I found was that with the dampers set too firm the suspension had a hard time keeping up with the movement of the wheels, with the result that even though the cornering speed stayed more or less the same the whole car started going up and down instead of the movement being taken up by the suspension. Very uncomfortable!
but after a little experimentation on my favourite piece of twisty road, which is serendipitously located between my house and my office, I was able to determine the setting at which the cornering speed was maintained at its highest level while keeping the ride as comfortable as possible.
I imagine that with stiffer springs (or torsion bars in my case) a stiffer damper setting would be called for. But barring that, it seems to me that stiffening the dampers only is pretty much pointless.
This experience has also demystified to me the reason why chavs in lowered Japanese family sedans look so jittery and anxious
What I found was that with the dampers set too firm the suspension had a hard time keeping up with the movement of the wheels, with the result that even though the cornering speed stayed more or less the same the whole car started going up and down instead of the movement being taken up by the suspension. Very uncomfortable!
but after a little experimentation on my favourite piece of twisty road, which is serendipitously located between my house and my office, I was able to determine the setting at which the cornering speed was maintained at its highest level while keeping the ride as comfortable as possible.
I imagine that with stiffer springs (or torsion bars in my case) a stiffer damper setting would be called for. But barring that, it seems to me that stiffening the dampers only is pretty much pointless.
This experience has also demystified to me the reason why chavs in lowered Japanese family sedans look so jittery and anxious
Greg 172 said:
I don't want to ruin it for you, but I seem to remember that it's actually Jaguar that do the whole thing with making the damper really firm to begin with and then softening it off a couple of miles later....
Jaguar has been watching the thread and, FWIW, I've been told that this is absolutely not the case with its adaptive damping system. For the record, etc...yes I am not sure about this. I was given a 911 (997 model) Carrera S for a couple of days while my car was having some work done. The car had a sport mode button as well as another button (can't remember the name!), so lets say it was a race mode button. Under normal mode the car was fine but compared to my 996 turbo, it felt a little soft and slow to respond. When I pressed the sport mode the whole car seemd to stiffen up and the throttle response was much quicker. It had PDK (automatic)and so the gears changed far more quickly and I was suddenly driving more aggressively. This tempted me to try the race mode:-) Wow the car went in to mental mode, dashing from point to point like a ferret chasing a rat. The ride was rock hard and everything happened lightening quick. So, is it a gimmick? Maybe. Technology for technologys sake? Personally I have to say that the ability to change suspension, engine note, gear ratios etc by the flick of a button was fun, and thats what it is all about isnt it?
herebebeasties said:
Much of why my Elise is so magic on B-roads is the damping. Soft springs, fast damping. Which seems to be the opposite of what most of Ze Germans seem to do, resulting in cars that are simultaneously uncomfortable and don't actually hold the road very well, other than on a track.
Lotus can get away with soft damping/springs on the elise because it is a light car, with a very low CoG. there are no german cars anywhere near as light as an elise so the damping will therefore be much more firm other wise it'd be like driving a boat. if you have a car which naturally doesn't want to roll (low weight, low CoG and suspension geo with cleverly placed roll centres) you don't need to control body roll as agressivly with damping/springs/ARB's
in a heavy car you need the dampers to be firm otherwise it won't feel sporty. i suspect the only reason the SLS can get away with non-adjustable damping is that it's predomanantly a GT car, ie. fairly soft.
Dan Trent said:
Jaguar has been watching the thread and, FWIW, I've been told that this is absolutely not the case with its adaptive damping system. For the record, etc...
Hmmmm, I reckon I'm going to have to plow through my old EVO collection tonight and see if I can dig out the article :-) I'm sure it was from the horses mouth, so to speak. Not really that iomportant, but now I have to know!rtz62 said:
The late, great LJK Setright would spin in his grave at these tricky-tracky adaptive dampers.
He was a man who loved pure engineering, and would have described adaptive suspension as a smokescreen to disguise the inadequacies of the chassis engineers...
Reading that made me smile - I reckon you're right, that's exactly what LJK would have said.He was a man who loved pure engineering, and would have described adaptive suspension as a smokescreen to disguise the inadequacies of the chassis engineers...
Edited by Johnboy Mac on Thursday 10th May 08:53
Dan Trent said:
Jaguar has been watching the thread and, FWIW, I've been told that this is absolutely not the case with its adaptive damping system. For the record, etc...
Are you able to extract a little more info from them? Are they replicating a frequency sensitive system where they are effecting changing the preload on the main high speed valves (knee point) to extend the low speed rate further up the shaft velocity for handling, but reduce that preload to open the high speed valve sooner for ride? Phil @ P5 said:
Are you able to extract a little more info from them? Are they replicating a frequency sensitive system where they are effecting changing the preload on the main high speed valves (knee point) to extend the low speed rate further up the shaft velocity for handling, but reduce that preload to open the high speed valve sooner for ride?
...which is why I leave the technical stuff to Phil! 
Strangely enough we were having a discussion in the office about this exact topic yesterday after the discovery of how the standard calibration for the switchable, active damping system from a major OEM.
The way it works is basically to stiffen up the damping in a straight line, then as soon as the driver issues a demand (i.e. a steering input), the dampers soften off and default to the standard setting. The implication is that it's stiff in a straight line to make the driver think it feels 'sporty', but actually the handling is upset by the change (most likely becoming more edgy and skittish) and the base, softer setting is always closer to optimal. So basically a useful system has been corrupted into being purely a marketing gimmick.
The conclusion we came to was that such a system performing as one would expect would be useful on a dual use car with the sport setup tuned specifically for track use, but that actually on the road a compliant setup is not just more comfortable but is actually better for handling.
The way it works is basically to stiffen up the damping in a straight line, then as soon as the driver issues a demand (i.e. a steering input), the dampers soften off and default to the standard setting. The implication is that it's stiff in a straight line to make the driver think it feels 'sporty', but actually the handling is upset by the change (most likely becoming more edgy and skittish) and the base, softer setting is always closer to optimal. So basically a useful system has been corrupted into being purely a marketing gimmick.
The conclusion we came to was that such a system performing as one would expect would be useful on a dual use car with the sport setup tuned specifically for track use, but that actually on the road a compliant setup is not just more comfortable but is actually better for handling.
wormburner said:
These systems that gradually ease back from 'sport' to 'standard'... at what point does the 'sport' light go out?
If this was happening surely people would be heading back to dealers to say their car won't stay in sport mode?
As I understand it (from my seemingly poor memory of an article), when you press the 'sport' button the dampers change to a firmer setting and remain there - they don;t go back to standard ove time. It's just that it gives you a couple of miles (or whatever) of additional firmness to confirm to your senses that you're in a sportier mode.If this was happening surely people would be heading back to dealers to say their car won't stay in sport mode?
For a VERY simple example, something like this:
Standard damp rate = 100%
Sport damp rate for first 2 miles after button pressed = 160%
Slacken back to actual sport damp rate = 120%
Hope this makes sense, these are just figures plucked from the air, using 100% as 'average' firmness.
Maybe someone more techy can give a more accurate explanation?
Proof that a lot of modern cars don't ride properly is that whenever anyone catches a lift with me in my now 22 year old Mercedes 190 E (1.8, not a cosworth sadly) the first thing they comment on is how comfortable the ride is.
Driving other vehicles like Passats, Astras, Insignias etc they all seem to have a very stiff ride, yet still don't handle as well as they should.
The 190 floats across the ground and you frequently find yourself doing some surprisingly high speeds even on twisty roads.
Driving other vehicles like Passats, Astras, Insignias etc they all seem to have a very stiff ride, yet still don't handle as well as they should.
The 190 floats across the ground and you frequently find yourself doing some surprisingly high speeds even on twisty roads.
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