MDM....Have you tried this??

[h-manuk]

hi all

I'm finding the DSC cuts in far too often and was wondering how people have found the car with MDM mode on?

I belive MDM partially turns off the safety net within DSC and allows slip. I dont want to get a nasty surprise so want to know your experiences with it and whether the slip is easily controllable!

[cc3]

Drove at Goodwood circuit in dry with switched off. Grip is very strong and with it switched off power is pretty instant out of corners etc. Car is very controllable a joy to drive. Have also done the same on the road again I prefer it switched off however clearly a lot more risk !!

[EmmDrei]

Originally Posted by h-manuk

I'm finding the DSC cuts in far too often and was wondering how people have found the car with MDM mode on?

I belive MDM partially turns off the safety net within DSC and allows slip. I dont want to get a nasty surprise so want to know your experiences with it and whether the slip is easily controllable!

I don't drive mine with DSC on. When I start the car, I hit the button and set it to MDM when it's wet and DSC off in the dry.

If you can drive a rwd car, MDM is not much of a challenge, even in the rain. If you lack the experience, train with it first. The car has so much grunt, that the rear can step out in the wet in fourth, if you hit a bump wrong and are pushing hard. Even with MDM the DSC will take over at some point, but you can get angles of up to 45° (just my guess, haven't meassured). So if you don't have the experience as far as counter steering, etc. goes... train, train, train before you touch the button!

[h-manuk]

the UK roads can be quite bumpy with frequent camber changes and the DSC was reigning in the power too often.

thanks guys for the feedback. I will try driving with MDM activated and see how the car responds knowing that DSC will help if I overstep the mark.

[hwelvaar]

Does anyone know if the LSD is somehow connected or in relationship with the MDM mode, or not ?

As in "when the LSD is active, and MDM is not active for sportier driving, the electronics will cut on engine power."

I observed that I get frequent power cuts when driving public roads, coming out of a real slow and real tight corner. All my electronis are ON when driving public roads, and the ESP cuts in regularly in coming out of corners.
So wondering if this is related to the LSD noticing different wheel rotation speeds, and if this would happen less frequent with MDM mode.

[rapter]

Originally Posted by hwelvaar

Does anyone know if the LSD is somehow connected or in relationship with the MDM mode, or not ?

As in "when the LSD is active, and MDM is not active for sportier driving, the electronics will cut on engine power."

I observed that I get frequent power cuts when driving public roads, coming out of a real slow and real tight corner. All my electronis are ON when driving public roads, and the ESP cuts in regularly in coming out of corners.
So wondering if this is related to the LSD noticing different wheel rotation speeds, and ih this would happen less frequent with MDM mode.

I think the LSD is mechanical in its' nature and the computer monitors how the mechanics influences the vehicle dynamics

[Dan Parker]

MDM simply gives the traction control a little more freedom before it steps in. It isn't nearly as turned down as I would like. Don't think you are going to turn MDM on and suddenly have the car drifting around corners. It's nicer than having DSC on but it still has BMW Legal written all over it. I'd like to make MDM allow a lot more pitch angle before it intervenes and the tuner I'm working with is looking into it.
On track MDM was hardly different from leaving the electronics on. It was only when I shut it off completely that the car would really go full hooligan.

[sparoz]

Originally Posted by EmmDrei

I don't drive mine with DSC on. When I start the car, I hit the button and set it to MDM when it's wet and DSC off in the dry.

If you can drive a rwd car, MDM is not much of a challenge, even in the rain. If you lack the experience, train with it first. The car has so much grunt, that the rear can step out in the wet in fourth, if you hit a bump wrong and are pushing hard. Even with MDM the DSC will take over at some point, but you can get angles of up to 45° (just my guess, haven't meassured). So if you don't have the experience as far as counter steering, etc. goes... train, train, train before you touch the button!

Be careful when you counter steer with MDM, if you adjust the car after the electronics kick in, it goes the other way.

Just need to put to where you want to go and let the electronics do the work. As far as I know "Full" counter steering in MDM only can be done on the new M5.

I will have more play in the morning, but the few times I got caught with the back stepping out with MDM on, the car has already adjusted itself by the time I realised I have lost my rears.

[Dan Parker]

"I will have more play in the morning, but the few times I got caught with the back stepping out with MDM on, the car has already adjusted itself by the time I realised I have lost my rears."

Well said. Once you get used to MDM you can almost ignore the loss of grip and keep the throttle open, knowing the silicone is going to step in.

[Madozu]

To my experiece, MDM is kicking in quite early if you open the throttle, especially on some bumps. It's more reacting to wheel slip than reacting to yaw angles. However, MDM allows reasonable yaw angles if your driving style is more accurately described by "balancing your car through the corners" instead of "forcing the car into the corners".

As a former E36 M3 owner (321PS, no DSC at all) I prefer DSC off in the dry and MDM in the wet ... or when I'm not prepared to "surprises"

[hollysmac]

Originally Posted by Madozu

To my experiece, MDM is kicking in quite early if you open the throttle, especially on some bumps. It's more reacting to wheel slip than reacting to yaw angles. However, MDM allows reasonable yaw angles if your driving style is more accurately described by "balancing your car through the corners" instead of "forcing the car into the corners".

As a former E36 M3 owner (321PS, no DSC at all) I prefer DSC off in the dry and MDM in the wet ... or when I'm not prepared to "surprises"

I agree as a former e36 M3 & e46 M3 owner who autoxes. With everything off I think you would have to be really heavy handed to lose the car. Today I autoxed and the rear end would start to kick out. I would just relax and it would pull itself back in. I plan to leave everything on in the winter or with rain. With everyday driving and a certain amount of skill the MDM should be fine in good weather. It is awful in autoxing. In addition with everything off and the M button pushed it was too tail happy to be effective in autox; without the M button pushed it is quote nice.

holly

[EmmDrei]

@hwelvaar: The DSC monitors a lot of things. Among them is wheel spin (as it is also responsible for traction control). Since a lsd will always transfer torque to the wheel that provides more grip, that will cause a difference in rotation speeds (usually the inner wheel will spin), in a corner, that alone is obviously enough to make the DSC cut the power when left in stock mode. So yes, the two are connected, and no, the DSC does not control the lsd. The lsds basic principal is that of a hydraulic lsd.

@The "let the DSC do its job" comments: One thing one has to realize... the DSC may not even register, that a cars rear end has stepped out. The classic noob driver error is aquaplaning while the cruise control is engaged. The rear steps out very slowly, the DSC does not register. The cruise control registers a loss in speed and accelerates. The car will do the exact opposite of what one should do (countersteer and engage the clutch).

And the same thing is true, when driving the car on the edge. You can create situations where the DSC will cause the rear end to step out and you can create situations where the DSC will not even register, that the rear end has moved.

I have not yet experienced a situation, where the DSC created a "tank slapper" because I counter steered. I wouldn't know why that should happen... to me that's an urban legend. The car will kick out to the other side, if I "over-countersteer". Simple physics, has nothing to do with the DSC.

To the assistance systems in general: One has to realize, that the driver is basically doing something wrong, if the system engages. Powersliding is not the fastest way out of a corner, so the system is correct, if it trys to maximize traction. A driver that knows what he/she is doing can drive with MDM on on a racetrack and the system will not engage. DSC off allows more show... not necessarily more speed, if the track I'm running on doesn't just consist of hairpins.

[BrokenVert]

Yes and no. A certain amount of slippage does allow you to drive a bit faster.

But as far as pinning the throttle and letting it go of course the traction control will kick in. My stock motored 135 can cause that light to kick in up to 3rd gear at times...I don't know what your 1Ms will do but I can imagine that it will at least match that.

[Slappymangooze]

Hello, on my exp, MDM allows more wheelspin and angle so the lsd have the opportunity to be of use. If you let the dsc on, the power is cutted far sooner than the time when you'll feel the benefit of the lsd. But when mdm is on, it's far more agressive out of corners, or into it. It allowed me some drifting angle, but I was on busy road going sideways was not indicated. As Dan Parker said, even on mdm, you still get massive powercuts, and it'll take me some skills to fully feel the car and get the max of it. But damn, it's so fast in second after a sharp turn! The torque rush is the most challenging part to keep it straight.

[hwelvaar]

Slappymangooze, are you driving a 1M or a 118d (says your profile) ?

[gazz]

Originally Posted by Madozu

To my experiece, MDM is kicking in quite early if you open the throttle, especially on some bumps. It's more reacting to wheel slip than reacting to yaw angles. However, MDM allows reasonable yaw angles if your driving style is more accurately described by "balancing your car through the corners" instead of "forcing the car into the corners".

As a former E36 M3 owner (321PS, no DSC at all) I prefer DSC off in the dry and MDM in the wet ... or when I'm not prepared to "surprises"

As well as rear slip it also reacts to understeer quite strongly and dramatically cuts power. The intermediate setting is a lot more restrictive than I expected given the pre-release hype about "limited drift angles" and such.
Regarding the statement above that, when using the intermediate setting, careful balancing through corners will maintain a moderate drift more than a heavy handed throw it in approach - what appears to be a delayed onset of intervention may be a little illusory in that by being smoother you are simply taking longer to start to drift. The moment of intervention in response to a particular attitude of the car is still the same.
My own experience so far with traction control turned fully off, ( given that I have yet to run the car in so I haven't explored the limits - yet ) finds that the car seems to respond better to a more aggressive style than a gentle style. Particularly the front end, which will push wide unless I aggressively load the front outside tyre, then it can be balanced on the throttle quite nicely with very quick responses. This may change dramatically on a track at race type speeds requiring a subtler approach of course but given that 99.99999999% of my driving is street and back roads that may be irrelevant to me. I'm still playing with tyre pressures though it seems that the standard pressures are pretty close to the mark, though I'm not sure that I like the Michelin PS2s tendency to slip-grip-slip-grip. Or is that just the way I'm driving?
I suspect that this car is similar to the M3s in that it really comes into its' own at the sort of speeds that will land me in a lot of trouble one day.

[BrokenVert]

You nailed the issue with PS2s.


And honestly the car is a monster if you let it go, I never understood why people run TC on public roads but thats just me. Save that kind of driving for autox or the track.

And just a fun story. The last time I autoxed I finished a run with TC full off came into the paddock and turned of my car. Started up when I was my turn again and went. Only I had forgotten to turn the TC back off. I ran 3 seconds slower than my previous run.


I dont know the point of that story, but I like it, so you guys got to read it