What does "selective damping" actually do?
Thread Starter
MBWorld Fanatic!
Joined: Sep 2014
Posts: 1,822
Likes: 33
From: Whitefield, NH
2015 C300 Sport: Palladium, Premium, Multimedia, Leather, BLIS
What does "selective damping" actually do?
"The standard selective damping can instantly firm up for sharper response
in corners, while maintaining ride quality on uneven surfaces."
I just saw this in a C-Class brochure and I'm not really sure how this works. What exactly is this and what does it do? I've never noticed anything unusual during hard cornering, so I'm curious about this feature.
in corners, while maintaining ride quality on uneven surfaces."
I just saw this in a C-Class brochure and I'm not really sure how this works. What exactly is this and what does it do? I've never noticed anything unusual during hard cornering, so I'm curious about this feature.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
It's a calibrated mechanical bypass in the damper/shock absorber.
In Benz speak:
" The damping system provides for well-balanced ride comfort by optimising tyre vibration characteristics, damping and stabilisation according to the road surface conditions.
The AGILITY CONTROL suspension offers high ride comfort through selective adaption of the damping system to the prevailing road surface conditions. By continuously scanning the road surface it is able to improve ride comfort when minor bumps are encountered and to provide more effective damping and stabilisation of the vehicle in response to more substantial jolts.
The AGILITY CONTROL chassis combines the flexibility of a selective damping system with the effectiveness of a passive damping system. The comfort-oriented conventional spring/damper system is augmented as standard by a stroke-dependent damping function. The functional module of the selective damping system consists of an elastomer piston which offers the oil flow a bypass parallel to the conventional shock absorber plating when minor bumps are encountered. This reduces the level of damping in the +/- 10 mm range, markedly improving ride comfort and the tyre/road contact characteristics of the chassis. In case of heavier impacts on the chassis, the selective damping function activates the full damping effect. "
Effectively a passive variable rate damper dependent on road surface input to the suspension.
In Benz speak:
" The damping system provides for well-balanced ride comfort by optimising tyre vibration characteristics, damping and stabilisation according to the road surface conditions.
The AGILITY CONTROL suspension offers high ride comfort through selective adaption of the damping system to the prevailing road surface conditions. By continuously scanning the road surface it is able to improve ride comfort when minor bumps are encountered and to provide more effective damping and stabilisation of the vehicle in response to more substantial jolts.
The AGILITY CONTROL chassis combines the flexibility of a selective damping system with the effectiveness of a passive damping system. The comfort-oriented conventional spring/damper system is augmented as standard by a stroke-dependent damping function. The functional module of the selective damping system consists of an elastomer piston which offers the oil flow a bypass parallel to the conventional shock absorber plating when minor bumps are encountered. This reduces the level of damping in the +/- 10 mm range, markedly improving ride comfort and the tyre/road contact characteristics of the chassis. In case of heavier impacts on the chassis, the selective damping function activates the full damping effect. "
Effectively a passive variable rate damper dependent on road surface input to the suspension.
Last edited by Glyn M Ruck; Jan 26, 2015 at 12:36 PM.
Thread Starter
MBWorld Fanatic!
Joined: Sep 2014
Posts: 1,822
Likes: 33
From: Whitefield, NH
2015 C300 Sport: Palladium, Premium, Multimedia, Leather, BLIS
Glynn, the explanation refers to an Agility Control suspension. Are they saying that Agility does have an effect on the steel suspension damping? Is damping reduced in Sport as compared to Comfort? It has always been my understanding that Agility only worked with Airmatic, and not with any steel variant.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Stan ~ you need to move back to the W204 to understand the agility control suspension progression
1) Agility Control = Passive variable rate dampers with steel suspension (intelligent dampers)
2) Advanced Agility Control = Active magnetorheological dampers with sensors, controller etc. switchable with steel suspension.
3) Latest W205 Agility Control = Variable, switchable with Airmatic.
Option 2 with steel looks as though it will come back with C450.
Yes ~ W205 with stock steel suspension uses option 1.
1) Agility Control = Passive variable rate dampers with steel suspension (intelligent dampers)
2) Advanced Agility Control = Active magnetorheological dampers with sensors, controller etc. switchable with steel suspension.
3) Latest W205 Agility Control = Variable, switchable with Airmatic.
Option 2 with steel looks as though it will come back with C450.
Yes ~ W205 with stock steel suspension uses option 1.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
BTW ~ I understand the confusion in this regard. Benz promo literature is almost deliberately confusing. Marketing people taking license.
Thread Starter
MBWorld Fanatic!
Joined: Sep 2014
Posts: 1,822
Likes: 33
From: Whitefield, NH
2015 C300 Sport: Palladium, Premium, Multimedia, Leather, BLIS
PASM: "Sensors record all wheel and body movements. This enables intelligent adaptation of damper stiffness for the selected mode, optimizing contact between each individual tire and the road for even less roll and pitch."
I guess the steel suspension used by MB is not electronically regulated, so I see it more as non-selective than selective since the driver has no control of it. And it looks like "Agility Control" has no relation to "Agility Select." Very clever marketing.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
The Advanced Agility Control (active) does basically what PASM does. SA motorists want it back instead of Airmatic. Rumour is that it will be offered shortly here on W205. SA motorists loved it on W204.
Trending Topics
Member
Joined: Jan 2015
Posts: 82
Likes: 0
From: SF Bay Area
Mercedes C300, BMW X5
I'm used to the PASM on my Porsche which, apparently, is nothing like what MB is using here.
PASM: "Sensors record all wheel and body movements. This enables intelligent adaptation of damper stiffness for the selected mode, optimizing contact between each individual tire and the road for even less roll and pitch."
I guess the steel suspension used by MB is not electronically regulated, so I see it more as non-selective than selective since the driver has no control of it. And it looks like "Agility Control" has no relation to "Agility Select." Very clever marketing.
PASM: "Sensors record all wheel and body movements. This enables intelligent adaptation of damper stiffness for the selected mode, optimizing contact between each individual tire and the road for even less roll and pitch."
I guess the steel suspension used by MB is not electronically regulated, so I see it more as non-selective than selective since the driver has no control of it. And it looks like "Agility Control" has no relation to "Agility Select." Very clever marketing.
What bugs me is a couple reviewers stated that airmatic is not much better than the standard steel. Comfort mode seem too soft and leans too much in corner. The sport mode is just right. Yet, you can achieve the same thing with steel default. That should not be at all possible with amplitude based damper. I suspect they road in some reasonable roads.
Anyways, I like the steel suspension until I hit "travel" or adjust limit. It only happen in one stretch of road near my place. Every car I test drive it has a hard time with that road. Only my SUV seem to handle that road reasonable well but still annoying.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Member
Joined: Jul 2014
Posts: 132
Likes: 0
From: London
2013 C class Coupe 250 CDI
Glynn, the explanation refers to an Agility Control suspension. Are they saying that Agility does have an effect on the steel suspension damping? Is damping reduced in Sport as compared to Comfort? It has always been my understanding that Agility only worked with Airmatic, and not with any steel variant.
