Quote:
Originally Posted by MFG
Digitalnoah/ezmaass,
Your profiles indicate Northeast US locations (and the corresponding rough pavement) so hopefully one or both of you can comment on this question.
When encountering a rough patch of road ahead (on a highway for instance)the instinctive response is to hit the brakes in an attempt to lessen the damage to the wheels & tires. This causes the front of the car to dive.
I would think Adaptive Drive would respond initially to the dive by stiffening up the suspension, aggravating the problem you are trying to lessen by slowing down.
What are your experiences/thoughts around this?
I'm all for avoiding handing "like a 1980s Buick" but am not interested in replicating Autoweek's experience with the F10 (7 RFTs replaced in 9 months): http://www.autoweek.com/article/2011...IEWS/111229921 |
This is a good question - I'll have to try it when I return home (in London on business this week).
I don't know if the system actually works the way you're describing, however. Do the dampers stiffen on nose dive? I don't know... but I'm doubting it's correct.
There are two parts of the system here that make up DHP:
- Electronic Dampers
- Active Roll Stabilization
The dampers, as far as I know and can tell in practice, are only set to a particular stiffness via the Dynamic Drive rocker switch. So, if you set them to Comfort+, they're going to be soft. If you set them to Sport or Sport+ they're going to be stiff. I don't believe they'll change stiffness on their own. I could be wrong. If they do, I haven't noticed it, and it would have to be very instantaneous. Keep in mind that the dampers control RECOIL only. The spring rate is fixed. So I highly doubt that the car would change the damper rate to help with a nose dive... someone correct me if I'm wrong here?
Second is the ARS. ARS only works laterally in cornering as the name implies. It can't work front-to-back. There are active sway bars that twist and create torsion to counter the forces applied to the car in a lateral acceleration situation, helping to keep the car's body from rolling side-to-side. But, since this would have no impact on a nose dive situation, I don't think this system would come into play either. Again, if I'm wrong - someone please correct me.
I'll be happy to play with it a bit and see what happens, but my gut tells me that neither the dampers or ARS would react differently in any driving dynamics mode to emergency/hard braking, as I don't think either system could help. The damper stiffness appears to be manually set only (at least it's been my experience - I don't sense the damper rate changing on its own), and the ARS appears to work dynamically in all driving modes, but it only works laterally for controlling cornering handling. The only thing that would help in your scenario would be spring rate - which is fixed.