[603BlueM2]

I have always believed that there is no such thing as a stupid question, so here goes: Can some one explain to me the difference between dynamic stability control and M traction control. Why I might want one but not the other? Should I turn off DSC for autocross but not traction control? Thanks in advance. Cheers.

[two_three_two]

its in the manual, but i think the simplified version is that DSC clips the brakes when it detects "dangerous" driving, and M traction control simply utilizes the electronic LSD to direct power to one wheel or the other (or pulls power entirely). i'd recommend turning DSC off for autocross and leaving the traction control at around an 8 to start and go down from there. i have DSC off 99% of the time i am driving.

[RobM2]

This is a great question and I don't feel the manual paints the full picture.

Appreciate the answer so far!

So, if

DSC = brakes + LSD + power moderation

DSC off = LSD + progressively less power moderation as you lower the traction control

What does M Dynamic Mode do?

[mrdudley]

Originally Posted by RobM2

This is a great question and I don't feel the manual paints the full picture.

Appreciate the answer so far!

So, if

DSC = brakes + LSD + power moderation

DSC off = LSD + progressively less power moderation as you lower the traction control

What does M Dynamic Mode do?

MDM is like traction control light. It will let you step the rear out but hopefully save you if you push too far. But it can bite you.

As the name implies it’s dynamic so how much it intervenes is dependent on a whole bunch of things. And I recall seeing it roughly maps to 6-8 traction setting depending on circumstance.

[RobM2]

Originally Posted by mrdudley

MDM is like traction control light. It will let you step the rear out but hopefully save you if you push too far. But it can bite you.

Yup, I get that, I'm trying to understand what that actually means technically.

[JMcLellan]

Which setting (DSC, MDM or perhaps both) includes steering intervention? I recall seeing a warning on the screen when turning either DSC or MDM off that steering intervention will be turned off.

And what does steering intervention mean?

[jhstjh]

I've been referring to this post for what each level of M traction mode does: https://g80.bimmerpost.com/forums/sh...3&postcount=11

[RobM2]

Originally Posted by jhstjh

I've been referring to this post for what each level of M traction mode does: https://g80.bimmerpost.com/forums/sh...3&postcount=11

This is super useful, thank you.

Still curious about the difference between DSC On and MDM.

[603BlueM2]

I find this all interesting, but I think I am more confused now then when I first posted the question. There does not seem to be a clear answer.

[RobM2]

Originally Posted by 603BlueM2

I find this all interesting, but I think I am more confused now then when I first posted the question. There does not seem to be a clear answer.

Same. Part of the confusion is BMW has 3 modes (DSC On, MDM, DSC Off), with the last having 10 stages, and in reality all of these have some level of traction control, except maybe stage 0 of DSC Off. So the nomenclature isn't helpful.

There's a number of things the car can do to maintain stability and traction — torque vectoring/slip, engine moderation, braking, steering intervention — and it would be great to know from BMW engineering exactly which lines up with each setting, and to what degree.

To put this in practical terms, many forum members here drive around in MDM mode much of the time. It would be super useful to know what we're losing in doing so.

[two_three_two]

i think of MDM as "level 11" of the 10 stage M traction control. it requires DSC to be off. I believe DSC is the only form of driver control assistance that includes "steering intervention" (other than, of course, lane departure).

DSC being ON means all the other nannies are ON.
MDM being ON means DSC is OFF
M traction control requires MDM and DSC to be OFF
with M traction control at ZERO but ON, means there are zero nannies between you and the guardrail

i believe this is to be correct, but of course will defer to any experts who chime in

[tylerdurdem]

Originally Posted by two_three_two

i think of MDM as "level 11" of the 10 stage M traction control. it requires DSC to be off. I believe DSC is the only form of driver control assistance that includes "steering intervention" (other than, of course, lane departure).

DSC being ON means all the other nannies are ON.
MDM being ON means DSC is OFF
M traction control requires MDM and DSC to be OFF
with M traction control at ZERO but ON, means there are zero nannies between you and the guardrail

i believe this is to be correct, but of course will defer to any experts who chime in

My understanding is that MDM is, as the name implies, dynamic, and acts like MTC level 4-7 depending on the situational parameters.

[Good 4 2 reasons]

Unfortunately the BMW video explaining the finer details is poorly translated into English without the necessary English nomenclature to understand what they are technically saying.

If you want to see a more practical demonstration of differing levels, I really enjoyed this video. It's more drift focused, but still demonstrates the results of different settings.

[jhstjh]

Originally Posted by RobM2

This is super useful, thank you.

Still curious about the difference between DSC On and MDM.

Found it. I knew I read about it somewhere

https://www.bmw-m.com/en/topics/maga...n-control.html

M Traction Control and MDM are different functions, hence there is no M Traction Control setting which equals MDM.
Simply spoken, M Traction Control is a slip control mechanism that controls rear wheel slip in 10 stages when DSC is switched off. Level 0 is OFF and allows for unlimited wheel spin. The higher levels allow for very limited slip. The slip is controlled using the engine‘s rpm as the only parameter. The vehicle’s yaw rate is not a controlled parameter here.
In contrast to M Traction Control, MDM is a part of the DSC mechanism and actively controls the vehicle‘s yaw rate. DSC/MDM use engine power controls as well as brake interventions to stabilize the vehicle dynamics on the road. MDM uses M Traction Control levels 4 to 7 depending on yaw rate behaviour.

So to my understanding: DSC ON = throttle control + brake control based on both wheel slips and yaw angle, at highest traction level 10.
MDM = throttle control + brake control based on both wheel slips and yaw angle, at dynamic range of traction 4 to 7. (Car will try to save you if you don't counter steer enough and/or give too much gas)
DSC OFF = throttle control only based on wheel slips, with 10 stages to choose from. (Car will NOT try to save you if you don't counter steer enough, but still cuts power if you give too much gas, until you turn it completely off)

[ajchoi]

Originally Posted by jhstjh

Found it. I knew I read about it somewhere

https://www.bmw-m.com/en/topics/maga...n-control.html



So to my understanding: DSC ON = throttle control + brake control based on both wheel slips and yaw angle, at highest traction level 10.
MDM = throttle control + brake control based on both wheel slips and yaw angle, at dynamic range of traction 4 to 7. (Car will try to save you if you don't counter steer enough and/or give too much gas)
DSC OFF = throttle control only based on wheel slips, with 10 stages to choose from. (Car will NOT try to save you if you don't counter steer enough, but still cuts power if you give too much gas, until you turn it completely off)

This is interesting. I've kept mine with all DSC ON so far because this is my first high power manual RWD car and I don't trust myself lol. I wish you could adjust the M traction control WITH MDM on, so I could ease into learning how the rear end acts with even more details (and protections from myself lol). I'll probably take a bunch of the M school stuff next year to feel more confident before doing it in my own M2 though.

[Kayger12]

It's getting old (and I had it bookmarked, because I'm getting old)-- but great succinct video explaining DSC.

As it was explained to me, DSC is significant because it can do what you can't-- apply individual braking at different wheels;

ie if you're driving in a straight line and swerve abruptly to the left, the DSC (if the vehicle rotation and wheel speeds don't match up within the ideal for the speed and steering angle input) will brake the driver side rear wheel to help the car rotate into the turn.

[apez]

I also find this confusing, but at autox try a few settings over different runs and it becomes pretty apparent. MDM vs 7 or 8 is harder to tell, but once you are below 5 or so you have to be much more careful with the throttle.

For those of you driving around in MDM, you still have to be careful! I definitely had a moment with MDM on where the backend kicked out and I wasn't fast enough/talented enough to save it while at a track event.