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      03-29-2013, 08:20 PM   #1
Ti-Jean
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Data showing Euro MDM applying brakes

I thought I'd share some data that I collected about euro MDM "interference" on track. I'm not looking to start a debate on the benefits or not to keep MDM on track, just wanted to share some hard data on what it actually does.

Here are 2 videos with associated data taken on the same track, same day, same driver, etc. Only difference is maybe 1 hour apart.

The short conclusion is that MDM will apply brake at individual wheel even if the car is not sliding. I could have understood this wrong initially but I thought that MDM would only kick in after some slip angle was reached by cutting throttle and/or applying brakes.

If you watch the following video, you can tell when MDM is doing something by looking at each wheel brake indicator (bar next to each wheel of the race car). If they light up whithout the brake pedal engaged, MDM is acting.

Few laps with MDM on (Euro MDM) example of MDM kicking in at ~1:03 and ~1:15:


Few laps with DSC Off for reference:


Here is a quick picture showing what to expect when MDM is acting in the first video.
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      03-29-2013, 08:58 PM   #2
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Very interesting, thanks for sharing. Were you running the Contis on this run?
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      03-29-2013, 09:17 PM   #3
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What are you using for data acquisition to get this? Also what did you use to generate the video?
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      03-29-2013, 09:27 PM   #4
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Quote:
Originally Posted by tom @ eas View Post
Very interesting, thanks for sharing. Were you running the Contis on this run?
Yes. Ran the contis on both the sessions.

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What are you using for data acquisition to get this? Also what did you use to generate the video?
Aim Solo DL (CAN Bus) for data acquisition, Gopro cameras for video and Dahsware to overlay data on video.

Thanks to Tom@EAS for taking care of the in-car wiring and letting me borrow his Aim Solo DL unit The above video/data would not have been possible without his help.
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      03-29-2013, 09:38 PM   #5
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Is it just me or does it look like the car is out of shape when the brakes pulse? I didn't think it used as much front brake though.
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      03-29-2013, 10:59 PM   #6
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Could it be CBC?

I watched the video a few times and am wondering if it's possible that what's actually happening is CBC intervening?

http://www.bmw.com/com/en/insights/t...e_control.html

There's a thread over on 1addicts about this:
http://www.1addicts.com/forums/showthread.php?t=578573

Apparently on the M3 CBC is disabled when DSC is off. On the 1M it remains active by default even if DSC is off.

Just food for thought.
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      03-30-2013, 06:54 AM   #7
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Thanks for sharing this. It is also the impression I am getting when driving with MDM, albeit I do not have Euro MDM. It has always been my impression that MDM does quick interventions without flashing the light in the cluster.
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      03-30-2013, 07:03 AM   #8
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Quote:
Originally Posted by ayao View Post
I watched the video a few times and am wondering if it's possible that what's actually happening is CBC intervening?

http://www.bmw.com/com/en/insights/t...e_control.html

There's a thread over on 1addicts about this:
http://www.1addicts.com/forums/showthread.php?t=578573

Apparently on the M3 CBC is disabled when DSC is off. On the 1M it remains active by default even if DSC is off.

Just food for thought.
I don't think it is CBC. CBC should only be activated when the brake pedal is depressed. In the video, we can clearly see the brakes being applied when Ti-jean is on throttle with no brake pedal application. Further, I believe CBC remains activated even when DSC is off on the M3. It is my understanding that CBC is linked to ABS and not DSC.

Last edited by CanAutM3; 03-30-2013 at 11:04 AM.
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      03-30-2013, 10:43 AM   #9
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Originally Posted by CanAutM3 View Post
I don't think it is CBC. CBC should only be activated when the brake pedal is depressed. In the video, we can clearly see the brakes being applied when Ti-jean in on throttle with no brake pedal application. Further, I believe CBC remains activated even when DSC is off on the M3. It is my understanding that CBC is linked to ABS and not DSC.
I agree with the above. Brakes are being applied when I'm on the throttle and not touching the brakes, I think that's MDM acting and not CBC.

I think CBC is also acting but at different time. You can see it when I'm braking going into off-ramp (hairpin corner) at 0:20 (MDM video) and 2:30 (DSC off). Different braking pressures are applied on the left and right side tires.
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      03-30-2013, 02:15 PM   #10
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Interesting post. Thanks for sharing!
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      03-30-2013, 04:25 PM   #11
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People drive on the track in anything but DSC OFF?
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      03-31-2013, 10:27 AM   #12
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SWEET vid. Thanks.
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Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
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      03-31-2013, 11:00 AM   #13
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Do you have upgraded swaybars? I assume aftermarket suspension?

It's possible that in some of the corners you're lifting a wheel, causing MDM to assume you're slipping and apply the brakes.
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      03-31-2013, 12:47 PM   #14
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Also...square tires change the calculated wheel speed differential between the front and rear...right?
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      04-03-2013, 11:51 PM   #15
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Quote:
Originally Posted by DallasBoosted View Post
People drive on the track in anything but DSC OFF?
Yeah. They do. Some people think I'm nuts for turning if off. Rainman was even heard mumbling about it at one point after my PS2's spit me off the track in T16/17 at Chuckycheesewallawalla. I guess it's a safety net thing, but frankly it is too invasive for my taste. It's always dabbing the brakes at Cal Speedway on the banking or at Turn 11 at Chuckwalla. I wouldn't have gone spun in 16/17 if it was on, b/c I wouldn't have been going fast enough.

DSC and I aren't friends. I normally only run it on instructor orientation laps or when I'm running in the D or C groups. Great to show students how smooth you can be even at speed. Stock DSC is too intrusive for a fast lap though, imho.

The Euro MDM didn't seem that intrusive at all in the first video. Looked like you were getting some pretty good yaw angles at times and it didn't come on. It didn't seem to react to the curb assaults either.

Now, if we could get 2000's era F1 TC on the car, we'd have a different conversation.
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      04-04-2013, 09:55 AM   #16
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I think its OK to start with DSC on and then work your car control skills until you're confident in turning it off.

BUT...once you get used to it being off don't start going back to turning it on unless you can just go back to letting the computer do its thing. Because when the the DSC starts to kick in...think of it as a boxing match of you vs the computer. While this battle of you correcting, the car correction, you correct the car, the car corrects you...your car is going god knows where.

I just picked up a 328i for my wife from the PDC. I was doing the skid pad and the car almost went off into the dirt on the inside. I was instictively correcting the car but so was the computer.

Bottom line is you and car or the car and the computer might make a good dance partner. The car, computer and you? Doesn't work.
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      04-04-2013, 11:06 AM   #17
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Euro MDM is a pretty good compromise. For those of us who are out to have fun and want a high probability of not wrecking our cars, it's fairly unobtrusive. I rarely feel it come on while on track. On the street on cold tires a few weeks ago I almost had a spin on an open on ramp and had to make some very large steering corrections to save it. Euro MDM was on and I'm not sure it did anything so that particular instance warned me that you can still lose it with Euro MDM.
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      04-04-2013, 01:04 PM   #18
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Dash ware gauge

Where did you get the M gauge for your video?
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      04-04-2013, 01:19 PM   #19
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Quote:
Originally Posted by Transfer View Post
Euro MDM is a pretty good compromise. For those of us who are out to have fun and want a high probability of not wrecking our cars, it's fairly unobtrusive. I rarely feel it come on while on track. On the street on cold tires a few weeks ago I almost had a spin on an open on ramp and had to make some very large steering corrections to save it. Euro MDM was on and I'm not sure it did anything so that particular instance warned me that you can still lose it with Euro MDM.
I think that is exactly the point of the video. MDM does small corrections that most drivers (beginner/intermediate) would not feel. It is mosty the "big" corrections that are felt. In the video we can clearly see MDM applying slight brake pressure to the front/outside tire to limit/prevent oversteer. The car is clearly not yet in an oversteer situation when MDM intervened.

Someone that drives on track only with MDM will continue to apply more throttle and/or more steering input than the grip can take and this WILL become a bad habbit. I can recall a few forum members here that were adamently defending the use of MDM at the track, until they started driving without it

As I posted in the other thread, for a complete noob, using MDM is most likely the right thing to do. But IMO, as soon as one is comfortable on the track and the conditions permit, the aids should be turned off. If one feels they are at risk of crashing: slow down.

Last edited by CanAutM3; 04-04-2013 at 03:55 PM.
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      04-04-2013, 04:13 PM   #20
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Quote:
Originally Posted by The HACK View Post
Do you have upgraded swaybars? I assume aftermarket suspension?

It's possible that in some of the corners you're lifting a wheel, causing MDM to assume you're slipping and apply the brakes.
I have KW clubsport suspension with stock swaybars.

I'm always trying to get a picture with a wheel lifted but it seems pretty hard to get. Your theory is still possible though.

Quote:
Originally Posted by admranger View Post
The Euro MDM didn't seem that intrusive at all in the first video. Looked like you were getting some pretty good yaw angles at times and it didn't come on. It didn't seem to react to the curb assaults either.
I drove for some time with euro MDM and never felt it was that intrusive, except for hairpin style corner or when I mess up. My issue has been very fast front pad wear once I got fast enough. I think MDM is to blame for that. I used up 8mm of Endless ME20 in <2 days with MDM on.

Quote:
Originally Posted by Transfer View Post
Euro MDM is a pretty good compromise. For those of us who are out to have fun and want a high probability of not wrecking our cars, it's fairly unobtrusive. I rarely feel it come on while on track. On the street on cold tires a few weeks ago I almost had a spin on an open on ramp and had to make some very large steering corrections to save it. Euro MDM was on and I'm not sure it did anything so that particular instance warned me that you can still lose it with Euro MDM.
I'm all for Euro MDM on track (and even better DSC off) but I honestly don't see the use on street. I leave full DSC on for street use. And even with full DSC on, you can still lose it and crash. Plenty of examples of that. My recommendation is for you to simply leave it full DSC on for the street.

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Originally Posted by CanAutM3 View Post
I think that is exactly the point of the video. MDM does light corrections that most drivers (beginner/intermediate) would not feel. It is mosty the "big" corrections that are felt. In the video we can clearly see MDM applying slight brake pressure to the front/outside tire to limit/prevent oversteer. The car is clearly not yet in an oversteer situation when MDM intervened.

Someone that drives on track only with MDM will continue to apply more throttle and/or more steering input than the grip can take and this WILL become a bad habbit. I can recall a few forum members here that were adamently defending the use of MDM at the track, until they started driving without it

As I posted in the other thread, for a complete noob, using MDM is most likely the right thing to do. But IMO, as soon as one is comfortable on the track and the conditions permit, the aids should be turned off. If one feels they are at risk of crashing: slow down.
Very well said. I was surprise to see brakes being applied in my MDM video since the car was in good control. Euro MDM has let me drift quite a bit in some corners so I thought it wasn't kicking in unless I was too out of shape (drift angle). The point of the video is to prove that it is doing something even if you don't think so and could certainly explain the quick wear of my front pads.

For me, here is how I describe going from Euro MDM to DSC off from a driving perspective. While driving with Euro MDM, you need to make steering angle correction when the rear end comes loose but you don't have to worry about throttle input (the computer is doing that for you). Going to DSC off, you need to both make steering correction and modulate throttle to make it out in one piece. The earlier you learn to do both, the better
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      04-04-2013, 04:14 PM   #21
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Where did you get the M gauge for your video?
I made it myself from graphics I found online. I'm happy to share the files with anybody interested.
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      04-04-2013, 10:48 PM   #22
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Wow, crazy pad wear given the Endless' reputation for long life. Wow.

Great stuff.

Soooooo, how hard is it to code the euro MDM into the car?
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