Suspension Question re: Adaptive Drive

[Pex5]

I know this subject can get soupy and is veeeery often misunderstood by drivers and salesmen alike..but

I have driven my friends new X5 50i which has the sport activity pack with the 20 inch wheels and no adaptive drive. It's such an improvement over our 09' 4.8i sport with the 20s (which all have adaptive drive) in terms of ride quality and he's on the OEM runflats, while I swapped in non-runflat Bridgestones - which by themselves improve the ride in the 4.8 and its still not as good as the 5.0.

BTW: adaptive drive is simply the hydraulic roll bars that stiffen up only in corners to prevent/reduce body roll without the harshness of a permanently stiff anti-roll bar(s)

So my 1st question is: Do you think that adaptive drive will impact the harness of the suspension at all? In theory it's disconnected while going straight. But will it give the ride of a stiffer suspension in a corner - meaning feeling the bumps and harsh crashes over rough pavement.

My guess is the harshness in our 4.8 is mostly due to the sport suspension, namely the shock and spring rates. The sport activity pack now offered doesn't have sport suspension which I'm guessing is why my friend's 5.0 rides so much nicer than our 4.8. But you can now order a car without sports suspension yet with adaptive drive (not possible in 2009). Would such a car ride as smoothly as an equivalent X5 without adaptive drive...?


2nd question: Am I crazy or did adaptive drive come on all X6s up to a point and now its a $3,500.00 option?

Thanks,
DRP

[finagle69]

Did you perform a comparison on a corner? i.e. Fwy entrance ramp.

I'd suspect that an 09 w/ AD will corner better than an 11 w/o AD. I'm assuming that slight adjustments were made to the suspension for the LCI but am not certain.

My 08 w/ AD corners very well, but I can't say that It feels "harsher" when in a corner due to AD being active. That may be in your head.

I'm coming from a fully modded (suspension-wise) Infiniti G37 with coilovers, camber kits, sways, and braces. The ride in the X5 Sport with AD is "cush" compared to that.

[Richard in NC]

I have the 50i with M Sport and Adaptive Drive, but with 19s. It rides quite soft. I read that they did redo the suspension in the 11s.

I considered getting after market 20s but just didn't want to spend the money at this time.

[rh71]

it should also adjust for forward and backward "dipping" such as when coming to a quick stop or accelerating. The youtube video on adaptive drive pretty much illustrates it well.

[ard]

1. You cannot compare a 2,3 year old car to a new car in terms of ride and harshness. Rubber components are worn.

2. AD includes hydraulically modulated antitorsion bars AND struts. Go look at the parts on RealOEM.com Online BMW Parts Catalog if you don't believe me.

3. I would go no larger than 19" rims...unless you need larger rims to get larger calipers stuff in there to handle track duty, there is no need. For some reason consumers have been driven to 'big wheels look better' and it is really quite silly. All IMO. Tires will cost more, your handling (not ride) will suffer, and tire choices are less.

A

[Pex5]

Originally Posted by ard

2. AD includes hydraulically modulated antitorsion bars AND struts. Go look at the parts on RealOEM.com Online BMW Parts Catalog if you don't believe me.
A

I think you've nailed it mate. Adaptive drive came with every sport pack X5 from 07-09. So, every adaptive drive X5 from that period had a sport damper (or at least one with EDC which becomes a sport damper in "sport mode".

So, if you equip a 2011 5.0 with adaptive drive you get the same "sport" capable dampers - which I am looking to avoid. The traditional non adjustable ones are great.

As for the handling of the 5.0 without adaptive drive, like every BMW before 2003 it leans a tad, takes a set and then you lay into the pedal. Its linear progressive and not objectively inferior to adaptive drive. It doesn't become a Benz.

Thanks for the insight,
DRP

[ard]

So this was a strange thread... I thought you were looking for data on AD and what it includes...

Forget the concept of 'sport' dampers. AD has a setting called sport. BMW has a package called 'sport'. The only similarity is 5 letters. The sport setting in AD does not deliver the ride you get with 'sport dampers'.

AD as nthing to do with ride 'harshness' - it is about controlling dynamic body roll.

Kills me when people add HUD, running board and comfort access- and po-po AD as costing too much!....yeah, Im a fan

A

[Pex5]

Originally Posted by ard

So this was a strange thread... I thought you were looking for data on AD and what it includes...

Forget the concept of 'sport' dampers. AD has a setting called sport. BMW has a package called 'sport'. The only similarity is 5 letters. The sport setting in AD does not deliver the ride you get with 'sport dampers'.

AD as nthing to do with ride 'harshness' - it is about controlling dynamic body roll.

Kills me when people add HUD, running board and comfort access- and po-po AD as costing too much!....yeah, Im a fan

A

Here's where I disagree. This was the point of thread. BMW won't tell you as much, but based on the info. you cited, going with AD changes the dampers on the car, not just the antiroll bars. It's a heavy system and I'm confident guessing that both the springs and dampers are different on cars with AD. You'll notice on realoem that there's no pricing or part numbers for springs. It's because they need the vin so that the vehicles exact weight given it's options can be determined.

If you want the smoothest ride in an X5, don't check the AD box. Thats the conclusion you've helped me come to.

If you need to rip corners in the car (which candidly is an unrewarding experience compared to a sports sedan or sports car), then get the sport pack (which has AD) (which is what we have). But if you want a rig that rides nicer and looks sporty, get just the appearance package and no AD stand alone.

I knew this would get a little soupy.

DRP

[Alan Smithee]

Originally Posted by Pex5

As for the handling of the 5.0 without adaptive drive, like every BMW before 2003 it leans a tad, takes a set and then you lay into the pedal. Its linear progressive and not objectively inferior to adaptive drive. It doesn't become a Benz.

There are obviously strong opinions with regards to AD and its benefits, but I agree with you. AD may provide less roll while maintaining a comfortable ride, however, like all similar systems, it is artificial feedback, along with added weight and complexity.

I prefer the more typical BMW handling traits of the standard suspension, which works well with 20" wheels to provide truly BMW sedan-with-sport-suspension-like handling and a firm ride. And will do so for years, since there are no electronics or hydraulics involved.

[Jim E.]

Originally Posted by Pex5

Here's where I disagree. This was the point of thread. BMW won't tell you as much, but based on the info. you cited, going with AD changes the dampers on the car, not just the antiroll bars. It's a heavy system and I'm confident guessing that both the springs and dampers are different on cars with AD. You'll notice on realoem that there's no pricing or part numbers for springs. It's because they need the vin so that the vehicles exact weight given it's options can be determined.

If you want the smoothest ride in an X5, don't check the AD box. Thats the conclusion you've helped me come to.

If you need to rip corners in the car (which candidly is an unrewarding experience compared to a sports sedan or sports car), then get the sport pack (which has AD) (which is what we have). But if you want a rig that rides nicer and looks sporty, get just the appearance package and no AD stand alone.

I knew this would get a little soupy.

DRP

There seems to be a lot of confusion about the specifics of adaptive drive. I researched it quite a bit before I bought my X5 and concluded that, for my needs, I had to have this system. Besides, as ARD points out, I ordered HUD, running boards AND comfort access - so I'd be a fool not to get it.

So let's talk about adaptive drive for a bit because it's a very interesting and cool system. Note: nearly ALL of my information is either derived or taken directly from BMW's own literature.

In the E70, Adaptive drive combines Active Roll Stabilization (ARS) and Vertical Dynamics Control (VDC).

The primary goal of these systems is to reduce lateral body roll.

Separately:

VDC:
"The primary objective of the VDC system to improve ride comfort
while maintaining driving safety at an invariably high level. High
levels of ride comfort are achieved when the vehicle body hardly
moves along the vertical axis in spite of excitations of the vehicle

induced by cornering or by the road surface itself (bumps, gaps)."

ARS:
"The Dynamic Drive active chassis system also known as
Active Roll Stabilization (ARS) - is a revolutionary step in chassis and suspension
engineering. For the first time, the trade-off between handling/agility and comfort is
largely eliminated. This results in a new type of "driving pleasure" typical of BMW.

Dynamic Drive has two active anti-roll bars, which have a positive influence on body
roll and handling characteristics. The fundamental feature of Dynamic Drive is the
divided anti-roll bars on each axle. The two halves of the anti-roll bars are connected
by a hydraulic oscillating motor.


One half of the anti-roll bar is connected to the shaft of the oscillating motor, the
other to the housing of the oscillating motor. These active anti-roll bars control stabilizing moments:

• which reduce the reciprocal movement of the vehicle body,

• which make it possible to achieve high levels of agility and target precision

over the entire road speed range,

• and produce optimum self-steering characteristics.

During straight-ahead travel, the system improves suspension comfort because the
anti-roll bar halves are de-coupled, with the effect that the basic suspension tuning does not additionally harden when the suspension on one side is compressed."


As you can see, comfort is one important characteristic of adaptive drive. The FlexRay bus system is used in the E70 for the first time in a standard production vehicle. I found it interesting that it is capable of 10Mbps. Flexray is not owned by BMW but is part of a consortium. FlexRay - The communication system for advanced automotive control applications