MDM power delivery vs. all nannies off power delivery

[1SerieStud]

Hey all,

I've made it a daily habit to drive in MDM + M (sport) mode. Tonight I was doing some spirited driving and noticed that when the M buttons is pressed but the nannies are completely turned off, the car seems to pull a lot harder.

So even though BMW says that MDM mode follows a complex algorithm allowing the car to put the power down and spin its tires, it seems like it still still rather restrictive. Is this my butt dyno lying to me, or is the car truly faster with all the nannies off?

[Dan Parker]

Your butt does not lie. MDM (on track) was a bit slower then everything off when comparing the data. I remember thinking the BMW attorneys were still sitting in the back seats. They just had a slightly looser grip on my neck with MDM on. It would have been nice if they had backed off MDM's intervention another 30% but they want to keep 1M's from ending up in the shrubbery. All off is the way to go, especially at corner exit.

[ChrisBuer]

I know it doesn't but with the M button (sport mode) on, i swear the steering feels lighter and more direct.

I'm going on track in a few weeks and am looking forward to trying the car in the various stability modes.

[1M SUSI]

Your butt does not lie.

<--- Hilarious

I can't wait for my first track day.

At least with all of the nannies turned off if your tail comes out you just lift and it will come back. In my ol 911 w/no LSD if the back end comes out and you lift it turns into the "spinning hippo". So with that said I'm not too worried about turning the nannies off on a track day. But I'll start with them on just to ease into it. Than when I let my hair down it's full on hooliganism.

susi

[bdaddylo]

Originally Posted by 1M SUSI

<--- Hilarious

I can't wait for my first track day.

At least with all of the nannies turned off if your tail comes out you just lift and it will come back. In my ol 911 w/no LSD if the back end comes out and you lift it turns into the "spinning hippo". So with that said I'm not too worried about turning the nannies off on a track day. But I'll start with them on just to ease into it. Than when I let my hair down it's full on hooliganism.

susi

you'll never have your nannies on again at the track after your first lap.

[Dan Parker]

I don't recommend an abrupt lift when the rear comes around. Weight transfers to the front and then the rear gets light. I found the car likes some throttle modulation at oversteer, not a lift. Not telling anyone how to drive, just don't want to see another crooked 1M.

[nachob]

Not been on track yet but did a fast autocross and with nannies off, it was very easy to overwhelm the rear tires if you put the hammer down. I was running Michelin Sport Cups 265/35/19. Lost it the first three times and killed a few cones. This was my first time with nannies off, so unless you are a veteran tracker like these guys, I would recommend turning the nannies off at an autocross first before the track. Once you drop the hammer and the rear gets spooling even backing off the throttle didn't save me. Too much spinning inertia and short wheel base. This baby comes around. .

The car does feel stronger with MDM off probably because the brakes aren't stopping the power. It seems like MDM is very active in our cars and we might not be noticing the light blink. Anyway, if you are veteran track guy, disregard, but if you haven't driven it all out with TC off, you might want to try an autocross first. After first three runs, I was able to keep it on the course the next 4 runs.

The following day, I ran the autocross in MDM and my time was a little better so that tells me, I have a lot of learning to do. Good luck and keep it pointing north and south. Don't forget, even The Stig lost it in the 1M.

[-cj-]

From what I gathered from reading the manual, briefly, was that the light only blinks if the stability programming "fails". Meaning, you're over whelming the system. From my understanding, it's always active, even in MDM mode (obviously just more forgiving), but a yellow light won't flash unless you're REALLY spinning the tires, or the car is really going sideways.

I've been meaning to go back and confirm...

[Die ///M Rakete]

+1 on the car feeling stronger in lower gear straight line acceleration with all electronic safety nets disabled. Even without the traction light blinking with MDM on it still feels like the power is being held back some.

[bdaddylo]

For novices, you should attend a car control school. Most car clubs offer this class on an annual basis. As with any high torque rear-wheel drive car, it is easy to break the rear tires loose.

Traction control, DSC, MDM utilize both the engine and brakes to control the car. This is why the 1M will feel sluggish.

[robertm]

The car feels faster without the traction control on because it intervenes right when the ls diff is trying to put the power down for ya. I really don't like the traction control at all and the first thing I do when I get in is turn it all the way off. It's the only way to really be able to drive the car. The car is extremely well behaved, provides a lot of feedback and will do exactly what you tell it to do. You will be amazed at just how capable the car is and how well it responds to input but you have to turn off the tc in order for it to behave properly.

Rain would be the one exception. Not smart to mess around in the rain on the street so best to just leave it on.

[1SerieStud]

Originally Posted by EIN M

+1 on the car feeling stronger in lower gear straight line acceleration with all electronic safety nets disabled. Even without the traction light blinking with MDM on it still feels like the power is being held back some.

Yep, exactly my point!

Originally Posted by robertm

The car feels faster without the traction control on because it intervenes right when the ls diff is trying to put the power down for ya. I really don't like the traction control at all and the first thing I do when I get in is turn it all the way off. It's the only way to really be able to drive the car. The car is extremely well behaved, provides a lot of feedback and will do exactly what you tell it to do. You will be amazed at just how capable the car is and how well it responds to input but you have to turn off the tc in order for it to behave properly.

Rain would be the one exception. Not smart to mess around in the rain on the street so best to just leave it on.

I'm very tempted to start driving this way, obviously in a responsible manner. Just like the first thing I do when I sit in my car is turn MDM on and press the M button, I think I can get used to turning TC all the way off and pressing the M button. I just have to readjust to the car's power delivery which feels much stronger.

[mayhewjr]

This is good stuff to know. I only turned the nannies off completely a couple brief times between break-in and snow tires, but I drive 90% of the time in MDM. (The first day I had 18" snows I tried driving with the traction control off and was spinning the wheels at the first green light with a very moderate right foot.) When spring comes and the OEM Michelins go back on I'm definitely going to explore the 1M sans traction control!

[nachob]

Originally Posted by bdaddylo

For novices, you should attend a car control school. Most car clubs offer this class on an annual basis. As with any high torque rear-wheel drive car, it is easy to break the rear tires loose.

Traction control, DSC, MDM utilize both the engine and brakes to control the car. This is why the 1M will feel sluggish.

+1 and I want to raise. : )

I think this Novice thing is really misleading. When you hear that from editors and fellow owners, it is misleading. Very few here are actually novices. I am not a novice. Even with a lot of experience with quick cars, the 1M is different. The short wheel base, tons of torque and more importantly the overboost. Because the ECU decides when overboost comes on in the right condition, as a driver you can get 320 lb ft or 369 lb feet. So I want to raise on this statement....not just novices, but those new to the 1M should autocross and take a driving school. As I said, the Stig is no novice and he got thrown off the track in the 1M. Tiff Nedell, got scared on his drive and put the traction control back on so not just novices need to respect the car. Perhaps it should be 1M novices.

[clived]

Originally Posted by nachob

Tiff Nedell, got scared on his drive and put the traction control back on so not just novices need to respect the car. Perhaps it should be 1M novices.

I asked Tiff about that footage. He wasn't scared, just making a point.

[nachob]

Originally Posted by clived

I asked Tiff about that footage. He wasn't scared, just making a point.

OK, I don't know him personally just based on his video it seemed to catch him off guard. The Stig got tossed and if Tiff was making a point, that is the same point I'm agreeing with and highlighting. I think the novice thing is misleading because few here are really novices but this car's character is different. Here is a better example:

experienced fighter pilots that flew P-40s had to be briefed and certified when they got P-51s. The character was different. Same goes for guys that flew Wildcats and Hellcats if they moved to a Corsair. It's a little extreme but hopefully you get the point I think something like those new to very high Horsepower cars should take a school, etc. I am not disagreeing with anyone, just that as I said, several here like myself are not novices per se, but this car can be a handful especially on bouncy roads with nannies off and high throttle travel.

Thanks.

[Fundahl]

Lol, literally the first thing I do every time after strapping in and starting the car is hold the TC button for 3 seconds.

[nachob]

Originally Posted by Fundahl

Lol, literally the first thing I do every time after strapping in and starting the car is hold the TC button for 3 seconds.

I wish I could make mine default to MDM for everyday. The full-monty is too intrusive. MDM is just right for everyday for me.

[Fundahl]

Originally Posted by nachob

I wish I could make mine default to MDM for everyday. The full-monty is too intrusive. MDM is just right for everyday for me.

Yeah, they should have an option in the iDrive menu. But that probably violates some law.

[bdaddylo]

Originally Posted by nachob

+1 and I want to raise. : )

As I said, the Stig is no novice and he got thrown off the track in the 1M.

In the Stig's defense, the track was wet and he hit a wet spot on a high speed sweeper. And even though he put the 1M in the wet grass, he didn't spin the rear around.

The 1M is no different from any high torque, rear wheel drive car where if you over drive it in a corner, it'll oversteer. The only issue I have with trying to learn car control by doing autox, is the minimal amount of seat time per each event.

[nachob]

Originally Posted by bdaddylo

In the Stig's defense, the track was wet and he hit a wet spot on a high speed sweeper. And even though he put the 1M in the wet grass, he didn't spin the rear around.

The 1M is no different from any high torque, rear wheel drive car where if you over drive it in a corner, it'll oversteer. The only issue I have with trying to learn car control by doing autox, is the minimal amount of seat time per each event.

Stig drives on wet courses all the time, it's England. Anyway, it's not a big difference of opinion just that I have driven powerful cars up 500 HP, last one being Shelby GT500. Also E46 and E90 M3. The 1M's non-linear delivery makes it a little more challenging when TC is off IMO. Some cars have a ton of power and torque, like the GT500 but it is more linear than the surge that hits the 1M.

I corrected on the turbo cars because it sounded like I was saying they were linear, I meant that I had driven powerful cars. Don't jump on me yet, just bad writing!

[jnm]

Originally Posted by clived

I asked Tiff about that footage. He wasn't scared, just making a point.

Well he certainly did a good job of looking surprised at how quickly the car started going sideways. It's certainly one of the last person you would expect to reach for the TC button so quickly .

Also while I have not tried myself I'm pretty certain the 1M does lift-off oversteer just as well as any other car. Be smooth with the throttle, both on the press down and on the lifting off when you slide too much.

I do agree with nachob though: the turbos (and over boost) can conjure a LOT of torque pretty quickly. Thats what makes the in-gear straight line acceleration of the 1M so impressive, but also what could surprise "novices".

One quick question though: if you turn TC all the way off, does the M button still make a difference? I seem to remember that when I had it off pressing the M button would not show the little "sport" text in the dash? (if you're going to turn TC off, meaning that you want to do some controlled sliding assumedly why do it otherwise, then the better throttle response of the M mode is a must IMHO)