What does the M button really do in technical detail?

[scotth944]

You can increase the timing low load part of the mappings to give the engine a snappier response to throttle inputs. I have done this to help make toe/heal combination for steering turn ins on corners easier. The down side I have found is that high load side of the mapping sometimes "feels" weak and there is nothing extra for the engine to give.

[tkbr0wn]

Seems like a good tuner would be able to alter this to include mdm mode as well.

[Lester]

It probably is more subliminal than anything. Because you've pressed the button, you are looking for better throttle response. Has anyone actually produced any kind of hard data on this? Does it reduce 0-60 times? Or is it subjective.

[Dee Pee]

Push button. Go fast. That's all you need to know.

[theblackangus]

Originally Posted by v1k0d3n

Saying (or repeating rather) increased "throttle response" is generic. Ok, I agree with you (never doubted)...increased throttle response. But let's liken throttle response to the color Blue. Now I'm asking is this Blue more of a sea-blue, or more of a baby-blue. HOW is throttle response achieved? That is the question.

The M button makes my car blue?
... Cool.

[mattm]

How do I make the button always "on?"

[JimD]

My earlier statement was incorrect. The M button is purely throttle mapping in the 1M. In the other Ms, it controls the stability control but the 1M retains the same button that the other 1 series cars have. It is supposed to be mapped differently, so that a single push gives you M mode - but you have two buttons on the 1M. You need to push both to get the M-mode of the M3.

Jim

[MDORPHN]

Originally Posted by Lester

It probably is more subliminal than anything. Because you've pressed the button, you are looking for better throttle response. Has anyone actually produced any kind of hard data on this? Does it reduce 0-60 times? Or is it subjective.

Of course, not. It changes throttle response only and has no effect on power. You can achieve exactly the same result with a sensitive right foot!

Neil

[sparoz]

Originally Posted by Lester

It probably is more subliminal than anything. Because you've pressed the button, you are looking for better throttle response. Has anyone actually produced any kind of hard data on this? Does it reduce 0-60 times? Or is it subjective.

It changes the throttle mapping, nearly stalled the car a few times when i forgot to press the M button while I gave it the same throttle. It also changes the gear change indicator to fuel saving mode to performance mode.

I will try the non M mode to see if there are any difference in over boost and lag. The throttle response in M is pretty instantaneous even at 2 grand. The over boost is easy to tell as you can feel when it actually kicks in.

Away on hols ATM so will try when I get home.

[tkbr0wn]

This is all I imagine that is happening when the m button is pressed. Just replace Sport with M. The curves may be exaggerated, and one of the two modes may actually be linear.

[Advevo]

This from the new M5 but it does the same for the 1M coupe. The sport button does more then only a shorter throttle pedal. I am sorry it s german maybe some one can translate it.

Wenn man die Fahrpedalkennungen Sport oder Sport plus wählt, wird das Ansprechverhalten noch einmal deutlich spürbar verbessert. Wie funktioniert das?

Durch geeignete Steuerung der VALVETRONIC und der Wastegates der Turbolader werden im Modus Sport und Sport plus die Turbolader auf höheren Drehzahlen gehalten. Normalerweise mache ich das Wastegate, mit dem der Ladedruck gesteuert wird, auf und sorge dafür, dass das Abgas möglichst verlustfrei ausströmt. Erst wenn ich Gas gebe, wird wieder Druck aufgebaut. Für ein verbessertes Ansprechverhalten lasse ich das Wastegate zu, bis ich es zum Regeln brauche. Das Abgas geht dann immer über die Turbine, die dadurch mit deutlich höherer Drehzahl fährt. Wenn Leistung abgefordert wird, steht sie damit sofort zur Verfügung. Allerdings habe ich so einen graduell höheren Gegendruck, damit steigt der Verbrauch etwas an. Deshalb ist diese Funktion auch schaltbar. Beim BMW 1er M Coupé wird übrigens die gleiche Funktion durch Drücken des M Buttons aktiviert.

[Aussie_in_London]

Durch geeignete Steuerung der VALVETRONIC und der Wastegates der Turbolader werden im Modus Sport und Sport plus die Turbolader auf höheren Drehzahlen gehalten. Normalerweise mache ich das Wastegate, mit dem der Ladedruck gesteuert wird, auf und sorge dafür, dass das Abgas möglichst verlustfrei ausströmt. Erst wenn ich Gas gebe, wird wieder Druck aufgebaut. Für ein verbessertes Ansprechverhalten lasse ich das Wastegate zu, bis ich es zum Regeln brauche. Das Abgas geht dann immer über die Turbine, die dadurch mit deutlich höherer Drehzahl fährt. Wenn Leistung abgefordert wird, steht sie damit sofort zur Verfügung. Allerdings habe ich so einen graduell höheren Gegendruck, damit steigt der Verbrauch etwas an. Deshalb ist diese Funktion auch schaltbar. Beim BMW 1er M Coupé wird übrigens die gleiche Funktion durch Drücken des M Buttons aktiviert.




If the accelerator pedal identifiers Sport or Sport Plus selects the response is noticeably improved considerably. How does it work?

By suitable control of the VALVETRONIC and wastegate turbocharger are held in the Sport and Sport Plus mode, the turbocharger at higher revs. I usually do the wastegate, the boost pressure is controlled, and making sure that the exhaust gas flowing out loss as possible. Only when I give gas, pressure is being rebuilt. For better response, I leave to the wastegate until I need it to regulate. The exhaust gas is always on the turbine that drives by with a much higher speed. If power is demanded, it is thus immediately available. However, I have such a gradual increase back pressure, thereby increasing the consumption of something. Therefore, this feature is also selectable. In the BMW 1 Series M Coupe by the way the same function by pressing the M button is activated.

[TunedM2C]

When I press the M button my catback exhaust gets much louder.

[jhall1957]

I haven't driven my 1M yet (picking it up Friday) but I have driven a new M3 9on track and road) and I have a E46 with a Sprint Booster that is a track and DD.

I believe the M button does more then the Sprint Booster. The Sprint Booster is great but I do think the M button changes the DSC. The car "moves" better on track.

Anyway, I should have a better answer on Friday evening as we are visiting the M Studio on Friday at 2 pm. From what I hear you get to meet several of the designers and engineers that planned/built the car. I'll make sure to ask them exactly what the M Button does and report back!

[v1k0d3n]

ok, so are we saying that there are hardware changes that occur when the M button is pressed? http://www.usautoparts.net/bmw/techn...alvetronic.htm This article may not be 100% correct, as it says: "Don't expect to see Valvetronic in the "M" series engines any time soon."

[MDORPHN]

Great new stuff about the M button.

Also found this from a thread on another site:

(Originally Posted by COBB Tuning)

"The alternate throttle maps offer varying amounts of engine power for throttle input. It is important to note that the pedal input does not specifically change the throttle plate on these cars. Instead, BMW has implemented logic to make the pedal input request a percentage of torque. The stock mapping has varying power output per pedal input depending on what part of the RPM band you are in."

Neil

[sparoz]

Did a WOT last night and thought something's not right - and I didn't have my M button on. I was travelling at around 40km in second before WOT.

Although the 1M doesn't have valvetronic, the difference in the waste gate could be the difference?

[GaryS]

Originally Posted by JimD

The M button is purely throttle mapping in the 1M. In the other Ms, it controls the stability control but the 1M retains the same button that the other 1 series cars have. It is supposed to be mapped differently, so that a single push gives you M mode - but you have two buttons on the 1M. You need to push both to get the M-mode of the M3.

Jim

The M button is user programmable in the M3. The user can specify settings for EDC (shocks), Servotronic (steering), Power (throttle map), and DSC (stability) for M button off and on. The last two are like the two buttons in the 1M.

[Moo]

What does the M button do when you have an ESS or GIAC tune?

[sparoz]

Originally Posted by GaryS

The M button is user programmable in the M3. The user can specify settings for EDC (shocks), Servotronic (steering), Power (throttle map), and DSC (stability) for M button off and on. The last two are like the two buttons in the 1M.

The M button on 1M doesn't change DSC. To put in M dynamic mode you have to use the DSC button.

[JasonCSU]

Here's a blurb from the "Interview: BMW M Head of Engine Development Details F10 M5 S63Tu Engine" thread that should help explain the technical detail better:

In Sport or Sport plus mode, a suitable VALVETRONIC controller and the waste gates keep the turbocharger in the higher speed range. Normally, the waste gate used to regulate the charging pressure opens so that the exhaust gas flows out with the minimum possible loss. Pressure is built up again only when I hit the accelerator. For an improved response, I leave the waste gate closed until I need it for regulating. The exhaust gas then always passes over the turbine, which then runs at a considerably higher speed. When even more power is demanded, it is immediately available. However, I have a gradually rising counterpressure that causes a slight rise in consumption. This function can therefore be switched on and off. By the way, in the BMW 1 Series M Coupé the same function is activated at the M Button.

Here is the original post:

http://f10.5post.com/forums/showthread.php?t=588858

[GoingTooFast]

The M button only gets you a sharper throttle response mapping. Unlike the new M5 the 1M engine (N54) doesn't have the VALVETRONIC feature (the single-turbo N55 engine in the late 135i does have it though).