Quote:
Originally Posted by jm1234
I'd guess that the EDC in "normal" mode is a closed loop control system and thus the damping ratio is the controlling variable and not a constant. In comfort mode I would assume a slightly underdamped system and in race a critically damped system (or perhaps even slightly overdamped). In normal mode though it's a question of what is being controlled? Is it ride height at each wheel (to control compression/extension); is it roll/pitch frequency/rate; is it lateral/longitudinal acceleration; is it a combination; or something else entirely? Any portion of the control system based on ride height is going to be negatively impacted by changing the ride height. The control system will see a constant downward offset which could (just guessing here) result in a constantly overdamped system. Portions of the control system based on roll/pitch/acceleration should incorporate spring rates and by changing the spring rates you will impact the system response but how would be more difficult to predict.
I don't see how you can take a controlled system and swap parts to change the response values and not negatively impact the performance. It's comparable to open/restricting the intake and exhaust on the engine but not changing the computer and fuel maps. The car might "look" cooler with lowered springs but unless you change the dampers; control system; and/or keep the car in a static suspension setting (comfort or race) then I think you'll suffer a variably compromised ride with difficult to predict consequences. I'm not predicting dire things just crap suspension feel (too stiff, too soft, bouncing, bottoming out, excessive roll, etc...) some portion of the time while in "normal" mode.
Does anyone know the details of how BMW's adjustable dampers work? I'm still curious and some of you seem to have a lot of engineering knowledge about the car.
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jm:
I think the questions posed in your first paragraph are important ones. I do know that piezoelectric technology incorporated into shock absorbers is not new, there must be something published on this. Hopefully someone can enlighten us. Just to confirm though, from what I understand, comfort is adaptive as well...Can someone validate this?