Originally Posted by lucid
A specific spring rate is most likely not hardcoded in the control algorithm. Moreover, there might not even be an algorithm, but merely a lookup table of some kind that matches measured acceleration data to predetermined damper settings. That might explain the “robustness” of the system althought an algorithm can be robust as well, but will be more precise by definition. However, I would refrain from making educated guesses on how robust the system is exactly. Any such educated guess would have to have solid technical justification to avoid constituting a mere hypothesis or lead to trial and error engineering.
I have been very clear that my statements about EDC are hunches and educated guesses, of course I have no proof. That being said I am confident enough in them to place bets! We do have some evidence that the "control system" is nothing more than a lookup table. BMW published that long ago and Greg posted it above. Of course that does not mean that the table is not supplemented with other parameters. Guesses are good and needed at this point is simply because folks want to swap springs and there is no conclusive answer nor proof of the affects both on longevity and performance. You may feel the need to be very conservative and rigorous, I generally do as well, but not in this case. Ultimately, like I said, without cold hard facts directly from BMW there will never be 100% certainty nor "rigor" in this discussion.