Quote:
Originally Posted by jm1234
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.
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I disagree with this statement. Well not the stament itself but the ASSUMPTION. The sensors used for the primary inputs for EDC are the three accelerometers, two front and one rear. Typically acceleromters are good at measuring ACCELERATION. Of course you can numerically integrate that signal and get velocity as well, if you have great equipment and/or DSP stuff and are very careful you can even get position information from an accel but it is tough. What is the point? The system is very likely position independent, i.e. meaning that the damping changes are based on instantaneous accelerations (or perhaps including some recent buffer/time history of what the suspension has been doing "recently"), nothing else. So the offset of the damper travel caused by a lowering spring should be fairly transparent to the control system.
A small thought experiment can help convince you that this is correct. What about ride height variation caused by max/min load cases (i.e. fuel and 1 vs. 3 or 4 passengers and possibly cargo). There will absolutely be a large noticeable change is ride height based on min/max loads and guess what EDC system will work just fine with a damper "offset". It has to.
BMW may or may not tell us the truth on this topic. As well the spring makers like to do BS like call springs "EDC compliant". I have no solid proof but strongly suspect a spring that would work and feel reasonable on the car (i.e. slightly shorter and somewhat stiffer) will very likely not adversely affect the EDC systems function nor longevity.
On the ride height issue: I am pretty pleased with with the cars ride height and looks. The rear wheels (19's) fill the wells beautifully and perfectly IMO. The front look slightly less "right" to me but definitely not nearly enough of an issue for me to muck with it, decrease ride quality, increase scraping and generally make the car more track like and less daily driver like.