EDC in M3 E92

[Edward]

Originally Posted by mdosu

IMO, No face palm needed only if:
You're a track rat, and buy some $10k Moton suspension that allows driver to independently dial in compression and rebound settings.

Else, sport springs, drop springs, only serves to drop the suspension and stiffen the ride, it doesn't necessarily improve track handling, and at best can only duplicate the performance of stock EDC programs.

Finally, the club racers (most HPDE guys) who buy the $2k-$4k KW V3 or Bilstein coilovers are likely doing it for that consistency the mechanical club racer shocks give you in terms of compression and rebound dynamics.

And remember the EDC settings are pre-programmed for a compliant street and sporty street driving where 95% of the aggregate worldwide owners' car's life will be spent doing. Why mess with it, and come out of your car with a pulverized pelvis and a crushed skeleton with a "stiffer" suspension?

Thats's what I mean. I know that a dedicated track car can handle significantly better with a new setup. But that set up would also be horrendous to live with if you drove your car anymore than once a week. So people put springs on the car and expect a better handling car when in fact sway bars would do far more for better handling.
Which leads me to believe that it is borderline appropriate to call springs a cosmetic mod. It's a compromise for a street driven car.

I can feel the changes in the dampening between the three modes, but I'm going to drive around and really see if I can sense changes in normal mode. Probably too biased to truly feel a difference now though.

[mdosu]

Originally Posted by Edward

Thats's what I mean. I know that a dedicated track car can handle significantly better with a new setup. But that set up would also be horrendous to live with if you drove your car anymore than once a week. So people put springs on the car and expect a better handling car when in fact sway bars would do far more for better handling.
Which leads me to believe that it is borderline appropriate to call springs a cosmetic mod. It's a compromise for a street driven car.

I can feel the changes in the dampening between the three modes, but I'm going to drive around and really see if I can sense changes in normal mode. Probably too biased to truly feel a difference now though.

yep, go ahead and test it out. Other than the default stiffness for each setting, when the EDC starts working and adjusting, the changes are so sutble and quick, most people won't feel it or notice it.

The best way to feel it working is:

1. drive in a straight line at a slow speed ~ 15 mph
2. drive on a smooth service, then over a speed bump, the higher the bump better. The more bumps the better (a cobble stone or brick surface street)
3. don't turn the wheel, drive over bump with same consistent speed
4. repeat on each setting, you can tell the difference in default stiffness and the shock's compression and rebound reactions' speed and "aggressiveness".

EDC adjustments made by the ECU is the most pronounced at slower speeds, straight wheel angle, and with a significant bump where the shocks are going through a longer travel.

[Edward]

Originally Posted by mdosu

yep, go ahead and test it out. Other than the default stiffness for each setting, when the EDC starts working and adjusting, the changes are so sutble and quick, most people won't feel it or notice it.

The best way to feel it working is:

1. drive in a straight line at a slow speed ~ 15 mph
2. drive on a smooth service, then over a speed bump, the higher the bump better. The more bumps the better (a cobble stone or brick surface street)
3. don't turn the wheel, drive over bump with same consistent speed
4. repeat on each setting, you can tell the difference in default stiffness and the shock's compression and rebound reactions' speed and "aggressiveness".

EDC adjustments made by the ECU is the most pronounced at slower speeds, straight wheel angle, and with a significant bump where the shocks are going through a longer travel.

I specifically have done this many times through a short cut alley I take to cut through a couple streets I don't want to take and it's very easy to tell the difference. but I mean feeling the difference through changes made on the fly by the ECU. Not from me actually pressing the button. Because this thread is the first time I learned that each setting is dynamic even if left in one setting.

[mdosu]

Originally Posted by Edward

I specifically have done this many times through a short cut alley I take to cut through a couple streets I don't want to take and it's very easy to tell the difference. but I mean feeling the difference through changes made on the fly by the ECU. Not from me actually pressing the button. Because this thread is the first time I learned that each setting is dynamic even if left in one setting.

yep! it's dynamic, ECU alters the size of the openings in the damper to change the piston speeds during compression and/or rebound

[grantmax]

Originally Posted by Edward

Personally woulnd't ever get this car without ZCP.
The flexibility is nice to have. My default driving mode is one light on. When I am driving on the actual freeway, I go down to the softest setting to absorb the bumps better at higher speeds. Only on really smooth streets or if I'm driving more aggressively, I will go to the stiffest setting.

I agree that it probably wouldn't make a lap time difference if I ever tracked this car, however, the car is easier to read as the rear wants to break loose if you are on the stiffest setting.

It's all about lap times. This is Brazil.

[kyrix1st]

Originally Posted by mdosu

From how I understand it, with non-zcp, normal and comfort are dynamic. The default on those settings are set at each respective stiffness. When road change, the stiffness can soften or stiffen up at different rates and stiffness. This is achieved by changing the orifcaces of the valving inside the shock which alters the flow rate of the fluid inside the shock. Normal's orifices likely are smaller as a default and expand the orifaces at a slower rate and to a smaller opening size than comfort.

You are correct that Sport is at it's stiffest 100% of the time and simply operates like a standard damper. The default orifaces openings in the shock doesn't change. Or if it does change depending on speed or other conditions, it operates much like a standard mechanical unit.

On ZCP cars, Sport becomes dynamic. The default opening of the orifaces are smaller and adjustments in the opening will be smaller.

All the computations of the rate of change, the opening size, and when orifaces are opening and closing are determined by the ecu as it monitors the cars speed and tire load.

I suspect EDC effectively can create a situation of semi independent compression and rebound characteristics. Though it couldn't be fine tuned by the driver like true race shocks.

The best part about it EDC is that it can provide optimal braking in distressed situations, by managing load in the front, and distributing the cars dive. This will enhance the effectiveness of the ABS.

http://www.m3post.com/forums/showthread.php?t=197521
http://auto.howstuffworks.com/car-suspension2.htm

ABS doesn’t have to engage to maximize braking. Car does stop much better in normal/sport mode than comfort.

[meyergru]

My 2cents:

1. ZCP EDC is not the same as the EDC option, at least in Europe. ZCP EDC is further optimised in sport mode.

2. The uplift for getting EDC in the first place is nowhere near the difference in price once you need to change the dampers afterwards: I know people who have replaced the dampers with normal ones and had the EDC removed from the car because of the price difference of 4 replacement dampers.