Richard in NC

Guys;
In an LCI 550i (or maybe 535i) with sport package, active roll stabilization, and a sport automatic (with the sport button). I have a question. When cruising on a bumpy road with the tranny in manual mode 5th or 6th gear (so the transmission doesn't shift), pressing the sport button seems to stiffen the suspension. Its a VERY subbtle effect but I do notice something. In the 650i, the effect of stiffening the suspension was more noticeable but no one believed me that the sport button effects the suspension (only steering and throttle).

Here's the test: cruise in 5th or 6th in manual mode. Be on a consistently bumpy section of road. Press the sport button. Bumps are slightly more harsh. I think the ARS "tenses up" to be more ready if thrown into a curve. Press again to disable sport mode. The suspension softens a bit. I absolutely notice this. Does anyone else?

westcoast550

Shocks ??

Richard in NC

Only on an M5 & M6 (& I think the new M3) with EDC are the shocks advertised as adjustable.

westcoast550

don't know. I had an older Pathfinder many years ago that allowed you to stiffen the shocks with the press of a button.......... someone here will know , great question BTW !

EBMCS03

You might be right... ARS might be able to stifen the suspension a bit... but i never noticed it... I dont drive on bumpy roads... I dont want it to knock things loose in my car... it rattles enough as it is...

MiamiPhill

Richard, the other day when I was under the car doing an oil change I took down the forward most air management undertray to make sure I didn't mistakenly drain the transmission instead of the engine oil. To my surprise, the sway bar had a quite substantial looking contraption (technical term ) surrounding about 8-10 inches or so of it, with what looks like hydraulic tubes and electrical wires coming out of it. (....now I wish I had taken a pic of it) That's when I realized that my car indeed had the suspension tightening feature I thought was 550i sport only feature. All this time I was in doubt because I expected an obvious effect like the distinct firmness I felt in my friends Audi TT with magnetic ride suspension, now I know to look for a more subtle change.

Richard in NC

Bump!

Any more thoughts on this? Rudy, is there conclusive proof one way or another that the sport button affects the suspension, at least the tension/readiness of the ARS? I KNOW I feel a difference in impact harshness.

SilberGrauE60

I believe you discovered the Active Roll Stabilization (ARS) apparatus! Active roll stabilization uses a hydraulic coupling in the middle of the stabilizer bars. This unit "decouples" when the car is going straight, allowing the suspension to be more compliant and the ride to be softer. When you make a turn, the stabilizer bars reconnect and keep body lean in check.

It is possible (can't say because I don't have an LCI car) that when the tranny is put in Sport mode, the ARS is "pre-loaded" and made ready for a slightly faster response. In my 2004 with ARS, I don't notice any "lag" anyway, but this might be a new feature on the LCI cars.

It is understandable that when ARS is "engaged" the ride will be harsher since any wheel bounce is counter-acted by the roll bars. Really, all the anti-roll bars do is attempt to keep the wheel to body/frame geometry the same giving the impression to the occupant that the body remains flatter in a corner.

katheikia

I asked this question two years ago and I still feel the difference. I think it has to do with the ARS....
http://forums.e60.net/index.php?showtopic=...hl=sport+button

Rudy

In the past (on my 2004 SMG car) I thought I felt a difference in the suspension when I pressed the sport button but I've never seen BMW mention any suspension adjustments in sport mode so I assume it doesn't do anything to it. I think, since the steering and the accelerator response is affected, it might create a perception that something is changing in the suspension when it reality, it isn't.

According to the manual, pressing the sport button (activating Dynamic Driving Control) does the following:

Dynamic Driving Control
The Dynamic Driving Control makes it possible
for your BMW to react in an even more performance-
oriented manner at the push of a button:

• The speed range of the engine is optimally
  utilized.
• Gearshifts are faster.
• The engine responds more spontaneously
  to accelerator pedal movements.
• The steering responds more spontaneously
  to steering wheel movements.
• In the automatic mode, the 6th gear is not
  engaged.