[Cyberdemon]

Originally Posted by RPM90

YES! You got it.
Except, the dampers don't use the magnetic fluid system.
They use electronic controlled valves to alter the valve opening size.

Interesting, good to know I was under the impression everyone doing adjustable dampers these days was using MR fluid.

[Elk]

Originally Posted by Cyberdemon

Interesting, good to know I was under the impression everyone doing adjustable dampers these days was using MR fluid.

The MR systems are incredible. Those GM engineers are exceedingly clever. I wish BMW used an MR system.

[Dust16]

Originally Posted by MaestroAl

You're describing the rebound function of a damper .. what about the bump settings? I don't want to bore you with it now but suffice to say, it's more complicated than that and the efects are much more pronounced The adaptive suspension is very, very good

Not doubting the system is good, but do bore me with the details please . RPM90's post seems to suggest that my explanation was indeed correct. If there is less roll in the M-adaptive, it would be because the springs are the same as in the M package (stiffer) and perhaps because the anti-roll bars are also different, but not because the dampers are electronically controlled. Unless someone can explain otherwise, I would believe that dampers have zero or very little effect on body roll (under a constant load - of course they would stop the car rocking back and forth sideways when exiting a corner due to lateral unloading).

Thx indeed to RPM90 for a lot of great info! BMW should make this kind of stuff available as standard documentation, they really assume their customers to be idiots with just giving us a few marketing-selected words to describe such a complex system.

[MaestroAl]

It's not that what's been posted is incorrect, it's just part of the story.

The lack of body roll is because when you go round a right hand bend, the left hand dampers are stiffened (bump damping) and so the resistance to compression increases greatly. I honestly have no idea if the M Sport suspension on which the adaptive is based comes with stiffened ARBs - I've never read anything about the ARBs on the 3 series to be honest.

Other than that, there's been some very well informed responses already so you don't need me to bore you further

[s2000jan]

Even when having the full adaptive M-suspension on my F30, I still find it to 'rock' too much (forward/backward) when coming to a full stop.

Other than that, it is very great !

[Dust16]

W.r.t. ARB's (Anti Roll Bars?), the only reference I found is the M Pack description (in Dutch), which says it has 'harder stabilisers'. They're not referring to the springs or dampers, because those are mentioned separately.

[MaestroAl]

Oh good find SO I wonder if you have a "normal" car and order the M Sport suspension, or the Adaptive, do you get the M Spec ARBs?

[HighlandPete]

Originally Posted by MaestroAl

Oh good find SO I wonder if you have a "normal" car and order the M Sport suspension, or the Adaptive, do you get the M Spec ARBs?

Standard suspension has a smaller front and rear ARB, than the M-sport of Adaptive M-sport which have the same ARB part numbers for either sport suspension system.

So yes, the sport suspensions have bigger diameter bars, front and rear. For example the European 320d has a 12mm rear ARB and 24mm front. The M-sport options have 13mm rear and 24.6mm front.

HighlandPete

[MaestroAl]

[HighlandPete]

Dampers cannot stop roll as has been commented on (when a contant load is applied) as that is directly due to weight transfer. But we do get benefits from damping systems that can respond to a higher level to slalom type movements and also to braking dive, etc. Hence why the adaptive damping can feel the car is 'tighter', as it is helping prevent the extemes of weight transfer in dynamic moves. Both compression and rebound can assist if stiffened within milliseconds.

The best system is that of the Adaptive Drive, where the roll bars are controlled. Having driven a 530d with Adaptive Drive, IMO, it is the roll bar control that tramsforms the suspension more than the adaptive damping. The fact it can hold the car flat when cornering, or when making slalom tyre changes, means the car feels so much more composed. Plus on straight flat driving when roll bars are a negative, particularly for single wheel bumps, the car definitely rides without the intrusion you often get when ARBs are really too stiff, as in aggressive sport setups.

I run passive 'selective frequency' dampers on my E91, and they are a halfway house towards adaptive damping. I can say with some experience that at low frequencies (as in cornering) the rebound damping stiffens up, does control how the car sits and does control roll more so than the standard OEM damper. But obviously if you "sit on a corner" the car can only resist roll by the capacity of spring an ARB rates. There is no miracle from any damper with a valve in it.

HighlandPete

[Dust16]

Originally Posted by HighlandPete

Standard suspension has a smaller front and rear ARB, than the M-sport of Adaptive M-sport which have the same ARB part numbers for either sport suspension system.

So yes, the sport suspensions have bigger diameter bars, front and rear. For example the European 320d has a 12mm rear ARB and 24mm front. The M-sport options have 13mm rear and 24.6mm front.

HighlandPete

Now this is what I called an informative thread! So basically once you spec M sports or M adaptive suspension, the only difference with an M pack car is the styling parts (other than a few options which you can obviously spec on the standard car as well, e.g. sports seats, M wheel, ...). Well at least in continental Europe .

[MaestroAl]

It's looking that way

[Micleg]

Originally Posted by Dust16

Now this is what I called an informative thread! So basically once you spec M sports or M adaptive suspension, the only difference with an M pack car is the styling parts (other than a few options which you can obviously spec on the standard car as well, e.g. sports seats, M wheel, ...). Well at least in continental Europe .

Ehhhh, it's no secret that the only difference to the handling och performance of an msport version is the sport suspension or adaptive suspension. You can get m sport suspension separately as well as the m sport wheel in Sweden. You buy msport to get a car that looks better. That's all.

[RPM90]

Originally Posted by Dust16

Not doubting the system is good, but do bore me with the details please . RPM90's post seems to suggest that my explanation was indeed correct. If there is less roll in the M-adaptive, it would be because the springs are the same as in the M package (stiffer) and perhaps because the anti-roll bars are also different, but not because the dampers are electronically controlled. Unless someone can explain otherwise, I would believe that dampers have zero or very little effect on body roll (under a constant load - of course they would stop the car rocking back and forth sideways when exiting a corner due to lateral unloading).

Thx indeed to RPM90 for a lot of great info! BMW should make this kind of stuff available as standard documentation, they really assume their customers to be idiots with just giving us a few marketing-selected words to describe such a complex system.

As Maestro writes, there is a lot more complexity to describing the interplay of the suspension parts and how they work and what they do.
And, all those parts affect what the other parts do as well.
Suspension tuning has been described as mostly science and black magic.

I can tell you that my adaptive suspension does affect body roll.
In comfort mode there is obvious body roll when going side to side and in turns. Set to sport mode, and clearly the system firms up control and reduces body roll.

I'll post some simplified info, but head to the web and find REAL articles on suspension tuning, rather than the sites that are marketing. Sellers of suspension parts can have some good info, but if you can find some good articles, they go into better detail.

Anti roll bars are mostly a fine tuning piece. Once you get the correct spring rate, and ride height, you get the dampers and tune the compression and rebound. Dampers don't/shouldn't affect ride height, that is done with the springs.
ARB's are then used to fine tune the interplay between left and right, and load transfer. They are designed to help equalize the load on the suspension left to right, by trying to keep both sides at the same height, which reduces roll.
Yes, they are "anti roll/anti sway/sway" bars, but they help fine tune the suspension.

Why does the damper help with body roll?
Dampers are a major component in the suspension along with the springs.
They help to control how the spring compresses and rebounds.
There is also low speed damping, and high speed damping.
If you could, turn the compression to full firm, meaning, the most resistance to allowing the spring to compress. In the damper, that would mean there is more resistance to the dampers fluid flow.
If you were to push/compress the spring, the damper would resist the compression. The spring would have a hard time compressing.
On the car, the vehicles weight would not transfer as it should and there would be less traction for the tire to grip the road.

In the other direction, if the damper were to set to easily compress, pushing/compressing the spring would meet little resistance from the damper. On the car, weight would easily transfer.

Too much compression damping can lead to less weight transfer and less traction, too little compression could lead to too much weight transfer, which could allow the car to wallow in the turn.

Let's say the compression is light. As you turn right, the vehicle weight compresses the spring. If compression damping is light, it will allow the spring to compress easier. Thus, weight transfer to that spring causes it to compress easily. If you firm up the compression, greater resistance to compressing spring, weight transfer won't compress the spring as far.
That side of the vehicle won't drop as much, thus it's flatter around that turn.
This is assuming the compression is set correctly.

Then, there is the suspension dealing with a bump. That's a sharp and quick hit, not like when turning. The damper has high speed circuit too. With a quick and sharp impact, the wheel moves up compressing the spring very fast. The damper fluid has to be able to move very quickly in order to absorb that quick energy. If the fluid can't move quickly enough the spring can feel like it's locked, thus the bump energy can't be absorbed by the damper and the energy is transferred through the chassis. Big band you will feel.

If the damper fluid moves too quickly such that it can't hold the spring before it fully compresses, then the springs coils will bang into each other and lock in that manner. That big bump will cause the spring to fully compress and lock and remaining energy goes through the suspension hitting the bump stop, and you get a big bang as well, though created by a different reason.

Suspension tuning is about getting the balance correct.
Adaptive dampers can respond to weight transfer initiated by a turn, or spring compression caused by a big bump. The adaptive damper can alter the valve openings continuously thus giving better control of the how the fluid/oil travels with the damper as it's absorbing different types of bumps and turns.

Then there is rebound damping and it's affect on how the spring returns to it's static state.
There are great suspension articles all over the web. Find some and read up.
They'll cover it better and in more detail than I, and I won't have to write more than I usually do.

BTW, I run RC nitro cars as a hobby, and the one aspect about it that I LOVE is how they relate to real cars. The suspensions on some of these cars is minuturized real car suspensions, and tuning the suspension uses the same ideas and principals as full sized cars, and the effects of tuning are the same as well. The coolest part is that you can pull a whole suspension out and modify the fluid viscosity, compression circuits, different springs and spring rates, damper mounting locations, and various stiffness of sway bars.
It gets expensive, but for a real car it's MUCH more expensive and you can't get to everything as easy. I digress.

[Ron Scott]

So, it's a must have? Thx.

[RPM90]

Originally Posted by HighlandPete

Dampers cannot stop roll as has been commented on (when a contant load is applied) as that is directly due to weight transfer. But we do get benefits from damping systems that can respond to a higher level to slalom type movements and also to braking dive, etc. Hence why the adaptive damping can feel the car is 'tighter', as it is helping prevent the extemes of weight transfer in dynamic moves. Both compression and rebound can assist if stiffened within milliseconds.

The best system is that of the Adaptive Drive, where the roll bars are controlled. Having driven a 530d with Adaptive Drive, IMO, it is the roll bar control that tramsforms the suspension more than the adaptive damping. The fact it can hold the car flat when cornering, or when making slalom tyre changes, means the car feels so much more composed. Plus on straight flat driving when roll bars are a negative, particularly for single wheel bumps, the car definitely rides without the intrusion you often get when ARBs are really too stiff, as in aggressive sport setups.

I run passive 'selective frequency' dampers on my E91, and they are a halfway house towards adaptive damping. I can say with some experience that at low frequencies (as in cornering) the rebound damping stiffens up, does control how the car sits and does control roll more so than the standard OEM damper. But obviously if you "sit on a corner" the car can only resist roll by the capacity of spring an ARB rates. There is no miracle from any damper with a valve in it.

HighlandPete

Great info on the parts Pete!
Much appreciated.

I would like to comment about dampers role in controlling "sway" "roll".
They do control those things as part of their design.
Anti roll bars/sways compliment the whole suspension during cornering, lateral weight transfer.
But it's not just the bar that controls roll. It's the damper WITH the bar that gives better/best control.
Active bars are an even further refinement on the bar idea, just as adaptive dampers are a further refinement of the damper idea.

Sitting on a corner of a car is a static test, and only demonstrates a springs compression and what the damper does with it.
In motion, in a turn, there are different forces in play.
In a turn, the car is suspended on the springs. Weight transfer is similar to sitting on a corner, but it's not the same. Sitting on a corner adds weight to that corner and the vehicle.
In motion, weight transfer is the vehicles weight transferring.

Sitting on a corner is more akin to encountering a bump. Vehicle hits the bump, wheel moves up, compresses spring, damper controls, spring rebounds. There really isn't an roll in that scenario.
ARB's help with weight transfer in a turn, they have little to no effect on a bump.

If I've misunderstood you, please correct me and explain.
I do find these discussions more informative then where BMW put the cup holders.

[HighlandPete]

Originally Posted by RPM90

If I've misunderstood you, please correct me and explain.
I do find these discussions more informative then where BMW put the cup holders.

Cup holders.... who cares. It is hard to believe that folks even seem to choose cars on things like how many and how good cup holders are.

Yes, you did read me wrong. Perhaps I should have been a bit more technical, rather than using "sitting on a corner" or for some, the more common "sitting on the sidewalls", for meaning "driving around a sweeping bend (corner) with a constant lateral weight transfer, where a damper won't help the roll characteristic of the chassis. No I was not referring to a static test, but during dynamic operation.

We know that springs, roll (sway) bars and tyres are the elements that control roll within the suspension design. Dampers can help in the speed of that roll and how lateral weight transfer occurs, but they have to be in travel to do anything to help. Dampers don't change the roll angles, as they don't support weight.

HighlandPete

[BMWCali]

Originally Posted by Ron Scott

So, it's a must have? Thx.

[Bjornizz]

Originally Posted by Cyberdemon

There are 3 total suspensions offered on the F30:

Standard - Which is what is on a non Dynamic handling equipped base model, luxury, or modern line (Softest, standard ride height)
Sport - This is the SAME on BOTH the M-Sport and Sport models. BMW simply mis-labels it to confuse you. The actual suspension components are the same. This includes the stiffer suspension, non adjustable dampers and a 10mm ride height reduction except on the X-Drive)
Adaptive - This is the sport hardware combined with the adjustable dampers. Again 10mm lower unless on an Xdrive.

I have never heard of the car not being lowered 10mm with xDrive. In fact I was talking to my dealer the other day and they said the car will be 10mm lower with xDrive.
May be different in the different countries though...

[Bjornizz]

Originally Posted by Micleg

Ehhhh, it's no secret that the only difference to the handling och performance of an msport version is the sport suspension or adaptive suspension. You can get m sport suspension separately as well as the m sport wheel in Sweden. You buy msport to get a car that looks better. That's all.

And with that look it makes it all worth it!

[mckmcr]

I also believe its worth it although my car doesn't have it...

I am not very disappointed because I love the way the car handles and I don't think Im driving a worse car because of that. I just know when im driving more aggressive where it could be more stiffer and have less body roll thats it.

All in all in UK its a £515 option and definitely a must-have if you're buying new (and used as well if you can check what options has it got)

Mine was 1 year old and £9000 cheaper than new so Im not going to moan even for a second.

[casualDIYer]

Ideally BMW would make it clear but my understanding was M Sport vs Adaptive MSport was in M Sport you select a fixed setting like on the Bilstein B16 Ride Control coilovers. So you select a setting, which then maintains a fixed behaviour. In adaptive you select a desired performance e.g. Sport but the car adjusts shocks so they tight on turns, braking, acceleration but soft on bumps i.e. adaptive to road conditions.

I expect adaptive suspension is the future of all cars.