Power button and Drivelogic

[///WeissBisBlau]

Originally Posted by FlyM3_R1

+1 ... I'm new here and dread the day I ask a question about my M3. I guess I'd better read this manual and study every page before I dare ask a question here. Kinda sucks really.

Man, just search for the answer first, and read your manual. If you still can't find it, post on it. People will answer you. Just ignore the trolls and look for the gold in the pan. Somebody will bring it. There are a-holes in here ( I mean c'mon, we DO drive Bimmers, after all...), but there are some nice folks, too.

[YolkyPalky]

Originally Posted by EvenSteven

For the third time, the DCT shifts exactly the same speed/force no matter what the setting. Google quickshifting vs. powershifting.

Seriously, asking questions that can easily be answered by a simple search is one thing, asking the same question in the same thread over and over is remedial. May god have mercy on your souls.

Uh, Wrong, try again.

Drivelogic modes affect BOTH the shift points, i.e., where on the RPM range the shift initiates, AND the speed at which the shift takes place. For Christ's sake it's written almost verbatim in the DCT Manual.


Easy explanation:

Low Drivelogic mode: Low shift points (shift initiates at lower RPM's), Slower shifts (makes for very smooth shifts), good for taking granny out to brunch, or baby to the park, etc.

High Drivelogic mode: High shift points (shift initiates at higher RPM's, gears hold longer), Faster shifts (sometimes even head-snapping fast). Good for kickass M3 driving!


If you are only driving the DCT in "S" or Manual mode (which you should be), then of course YOU initiate the shift points yourself, the Drivelogic mode will determine how aggressive/subtle the shifts will be. I.E. S1 - smooth easy shifts, slower shift times, S5 - fast, head snapping shift times

[///WeissBisBlau]

Above all, I just want to say GO DRIVE THESE BABIES!!! Seriously, just go experiment with all the settings. You will never "get" DCT Drivelogic settings until you experience them, and you won't experience them if all you ever do in your M is drive Granny to church!

[YolkyPalky]

Originally Posted by TexasSpartan

I didn't know what the "M" button did when I bought my car....

The "M" button doesn't "DO" anything! It is simply a user-defined pre-progammed engine/vehicle settings button. Kind of like when you have your favorite radio station on radio push button #1.

The "M" button is whatever you want it to be. You can set your "M" button to be full on "granny mode" for kids, elderly relatives, or you can set your "M" button to the most aggressive settings possible, it's YOUR choice.

It is simply a "hot button" to recall WHATEVER settings you program it to be.

[dparm]

Originally Posted by ILSMKU

You guys are dicks. Just help the guy out. This forum is going to shit with replies like that. Way to help a member out!

+1


Also, whomever said that Drivelogic doesn't change shift speed, you are incorrect. It was proven that the shift times are indeed changed:

http://www.m3post.com/forums/showthread.php?t=165773

[YolkyPalky]

Originally Posted by dparm

+1


Also, whomever said that Drivelogic doesn't change shift speed, you are incorrect. It was proven that the shift times are indeed changed:

http://www.m3post.com/forums/showthread.php?t=165773

This is also cut/paste directly from the MDCT Manual, page 40:

"In sequential mode the switching speed is affected which has a direct effect on the shifting firmness.

In drive mode the shift points and the shifting speed are affected, as a higher shift program means a higher gear changeover speed and thus a higher shifting speed."

[EvenSteven]

Originally Posted by YolkyPalky

Uh, Wrong, try again.

Drivelogic modes affect BOTH the shift points, i.e., where on the RPM range the shift initiates, AND the speed at which the shift takes place. For Christ's sake it's written almost verbatim in the DCT Manual.


Easy explanation:

Low Drivelogic mode: Low shift points (shift initiates at lower RPM's), Slower shifts (makes for very smooth shifts), good for taking granny out to brunch, or baby to the park, etc.

High Drivelogic mode: High shift points (shift initiates at higher RPM's, gears hold longer), Faster shifts (sometimes even head-snapping fast). Good for kickass M3 driving!


If you are only driving the DCT in "S" or Manual mode (which you should be), then of course YOU initiate the shift points yourself, the Drivelogic mode will determine how aggressive/subtle the shifts will be. I.E. S1 - smooth easy shifts, slower shift times, S5 - fast, head snapping shift times

You are 100% wrong. The dct always shifts at the same 140ms (110ms for GTS iirc). The roughness of the shift is due to throttle input.

[YolkyPalky]

Originally Posted by EvenSteven

You are 100% wrong. The dct always shifts at the same 140ms (110ms for GTS iirc). The roughness of the shift is due to throttle input.

Take it up with BMW, this is from their own printed material:

This is also cut/paste directly from the MDCT Manual, page 40:

"In sequential mode the switching speed is affected which has a direct effect on the shifting firmness.

In drive mode the shift points and the shifting speed are affected, as a higher shift program means a higher gear changeover speed and thus a higher shifting speed."

[EvenSteven]

The transition from one gear to the other with the DCT takes the same amount of time regardless of drivelogic settings. "Higher shifting speed" here means it shifts at higher engine speeds, as in higher RPMs, because it's specifically talking about the D mode.

[gatorfast]

Originally Posted by EvenSteven

The transition from one gear to the other with the DCT takes the same amount of time regardless of drivelogic settings. "Higher shifting speed" here means it shifts at higher engine speeds, as in higher RPMs, because it's specifically talking about the D mode.

Never driven a DCT car but I think you are wrong. Otherwise, what is the difference between s1-s6?

You are saying the shift speed is the same no matter what. So at full throttle in s1 you are saying the shifts feel the same as if you were full throttle in s6?

[dparm]

Originally Posted by dparm

+1


Also, whomever said that Drivelogic doesn't change shift speed, you are incorrect. It was proven that the shift times are indeed changed:

http://www.m3post.com/forums/showthread.php?t=165773

Again, see above URL. There are graphs where it was measured how long these shifts took. They have good resolution and show that there is a wide range of speeds.

Drivelogic is adjusting the shift speed and is doing things with the throttle between gears (which you can also see in the above graphs).

[EvenSteven]

If you actually read that thread, you will see the conclusion is that while the DCT shift times fall within a certain range (the 110ms I mentioned earlier was an average), the drivelogic modes do not have an effect on that speed, or at least the relationship isn't as simple as "higher drivelogic mode = faster shift". As the thread states, "S4->S6 with surge does not shift faster than D modes but it is faster [as in your speed after the shift will be higher]". You will also note that in this particular test, S4 was shifting slower (200ms) than D3 (35ms). Then there's the fact that the thread is comparing D and S modes, not individual drivelogic modes. So at best, with that thread you've tried to admit irrelevant evidence. At worst, you've only hurt your case.

I'll try explaining this again:

The DCT transmission allows you to maintain throttle while you shift, so there is no interruption of torque or pulling force. The various drivelogic modes modulate just how much of that power and traction is being applied during the shift. If you've ever driven a manual, "powershifting" means keeping the throttle wide open while you shift to try and replicate this. So rather than the revs stopping to climb when you let off the throttle to disengage the clutch, you actually momentarily over-rev until the clutch re-engages again. Watch your RPM needle next time you're shifting in S5, you can actually see the needle bounce a bit before continuing to climb. This gives you that rough surge feeling while in the car, and if you are watching a car do this, you can often see the wheels spin a little. This works slightly differently with a computer-controlled dual clutch, but the effect is the same.

And it is that wheel spin that the drivelogic modes are trying to control. In poor road conditions (rain/snow/etc), higher drivelogic modes can easily make you lose traction and spin out.

This is why the manual refers to S1 as the "winter program" and S6 as "speedy puristic".

If you are still skeptical, this is directly from BMW's documentation on the DCT transmission.

To provide an even more sporting driving impression and to further improve
the car’s acceleration, the M double-clutch increases torque and pulling
power to an even higher standard when shifting gears by means of the
appropriately configured Drivelogic programs. In conjunction with the small
increments between gears, these Drivelogic programs give the driver an even
more intense feeling of acceleration, sensing each gearshift as the starting
point for an even greater surge of power. The additional power generated
in this way comes out clearly in the new transmission ratio feeding torque and
traction to the drive wheels.

So again, the Drivelogic modes do not change how fast the transmission shifts, but rather how much power is delivered to the wheels during the shift. Depending on road conditions, you can actually get better numbers in a lower Drivelogic mode, just like you can get better numbers with softer suspension settings on rough roads.

[Dice13]

Originally Posted by MysticBlue

All these things have been discussed a million times over the years, but I'm bored, so...
1. Power button should not be labeled "Power" button, it should be labeled "Throttle Position Sensitivity". That's all it does. The computer looks at throttle position, 0-100%. The button just changes the curve that the computer sees for your pedal position. The power button makes the throttle more sensitive at the beginning of it's travel. You push it in 50% and instead of seeing 50%, the computer sees 70%. 100% is still 100% either way. There is no more than 100%. No more torque, no more hp. The power button does not add any torque or hp. Go to a track event and I guarantee the instructor will tell you leaving it on normal is better. Smoother is better.
2. 6th position of drive logic only comes up as an option when you turn off DSC. My advice is that you do not do this. This is where you start if you are doing launch control, which I also advise you not to do at this point.
In S mode, higher settings cause the transmission to shift faster and more aggressively and to rev match more aggressively on downshifts. You should be able to feel the diffence shifting at higher rpm under heavy throttle and you should hear the difference downshifting at higher rpm. You should really be able to tell the difference between 1 and 5. Again, 6 is only going to happen with DSC off. No reason for you to go there.
3. Shift indicator lights can be turned on in settings, I think under M settings. I don't remember specifically, but if you search around in the menus, you will find it. If you don't have nav, then you can use the thingy on the turn signal stalk.. someone else will have to splain that, or you could search. It's here somewhere.

I had a white 2011 M3 vert. I just got a 13 M ILB and fell in love all over again . If I recall right I set my old car up in S 6 the only way I drove her when DSC was off. I loved the way she drove and blipped on down shifts. I can not seem to get her programed to S 6. Is it because I did not do my break in period yet. Thats te only reason I can think of. I know you can not launch during break in and it wont let you. I really don't wanna do that any way.

[YolkyPalky]

Originally Posted by EvenSteven

If you actually read that thread, you will see the conclusion is that while the DCT shift times fall within a certain range (the 110ms I mentioned earlier was an average), the drivelogic modes do not have an effect on that speed, or at least the relationship isn't as simple as "higher drivelogic mode = faster shift". As the thread states, "S4->S6 with surge does not shift faster than D modes but it is faster [as in your speed after the shift will be higher]". You will also note that in this particular test, S4 was shifting slower (200ms) than D3 (35ms). Then there's the fact that the thread is comparing D and S modes, not individual drivelogic modes. So at best, with that thread you've tried to admit irrelevant evidence. At worst, you've only hurt your case.

I'll try explaining this again:

The DCT transmission allows you to maintain throttle while you shift, so there is no interruption of torque or pulling force. The various drivelogic modes modulate just how much of that power and traction is being applied during the shift. If you've ever driven a manual, "powershifting" means keeping the throttle wide open while you shift to try and replicate this. So rather than the revs stopping to climb when you let off the throttle to disengage the clutch, you actually momentarily over-rev until the clutch re-engages again. Watch your RPM needle next time you're shifting in S5, you can actually see the needle bounce a bit before continuing to climb. This gives you that rough surge feeling while in the car, and if you are watching a car do this, you can often see the wheels spin a little. This works slightly differently with a computer-controlled dual clutch, but the effect is the same.

And it is that wheel spin that the drivelogic modes are trying to control. In poor road conditions (rain/snow/etc), higher drivelogic modes can easily make you lose traction and spin out.

This is why the manual refers to S1 as the "winter program" and S6 as "speedy puristic".

If you are still skeptical, this is directly from BMW's documentation on the DCT transmission.



So again, the Drivelogic modes do not change how fast the transmission shifts, but rather how much power is delivered to the wheels during the shift. Depending on road conditions, you can actually get better numbers in a lower Drivelogic mode, just like you can get better numbers with softer suspension settings on rough roads.

You are so 100% wrong I barely even want to waste the time replying. Shift times are 100% effected by what Drivelogic program you are in, whether its S1-S6 or D1-D5. The length of time for clutch engagement, gear switch and clutch disengagement is absolutely longer and smoother in S1 than it is in S6. BMW says the exact same thing in their own MDCT Manual which was posted in this thread, check page 40. The quote you provided says nothing about shift times.

Anyways, I really could care less because I've been an original owner of an '02 M3 SMGII and an '11 M3 DCT so I've had plenty of years to realize empirically how slow and smooth the shifts are in low Drivelogic, and how lightening fast they are in high Drivelogic. It's almost laughable really that you are saying otherwise, since it's something BMW says and is generally known as true.

[Dice13]

Why can't I get S6 is it because I am in break in period.

[MysticBlue]

Originally Posted by Dice13

Why can't I get S6 is it because I am in break in period.

Yes, if I remember correctly. You definitely cannot do launch control until about 1250 miles. It's been awhile, but I think S6 is the step that you cannot get past... S6 is not selectable until after the break in period. Just an FYI, there is nothing the dealer does to reset, or enable the software when you go in for the break in service. It just enables on it's own at around 1250 miles, so if you get your 1200 mile service at 1200 or earlier, don't expect S6 or launch control to work right away. It still has to go over 1250.
Honestly, I don't know what the point of S6 is anyway (other than getting to launch control, if and when you chose to). If your whole point is getting aggressive sounding rev matching while downshifting, S5 does that, but I would be careful with that until after break in, but that's a whole other discussion. In any case, there isn't anything you can do in S6 that you can't do in S5 (other than launch control).

[EvenSteven]

Originally Posted by YolkyPalky

You are so 100% wrong I barely even want to waste the time replying. It's almost laughable really that you are saying otherwise, since it's something BMW says and is generally known as true.

Good thing I don't need to prove myself to someone with no understanding how the dual clutch works (the transition between two gears is seamless so there is no jerk when the clutch is reengaged because one clutch is always engaged), utterly fails at reading comprehension (your manual quote that is talking about D mode, the technical document that says what that surge actually is, or the linked thread that shows shift speed and drivelogic mode are not in a linear relationship), and whose argument is based on their SMG experiences (lol) and "that's generally known as true" which is another way of saying "a common misconception".

Keep wallowing in ignorance.

[Kung Fu English]

I love how everyone is like 'ZOMG UZE DE SEARCH NUB! DE ANSER IS SO OBVIOUZ'

Then everyone argues about the actual answer for 2 pages.

I have a search button too. It's labeled 'new thread'. Why have a forum if you don't want anyone to ever post.

And has anyone ever actually tried to search for something useful with a thread search? Especially a subject that is probably 5 years old? It sorts results by reverse chronology. So if you search for 'how does the power button work' you probably won't actually find an answer because it is buried under some no name thread, and all the threads that come up have replies that say 'use teh search lolz'.

[GVIFlyer]

Originally Posted by dparm

Again, see above URL. There are graphs where it was measured how long these shifts took. They have good resolution and show that there is a wide range of speeds.

Drivelogic is adjusting the shift speed and is doing things with the throttle between gears (which you can also see in the above graphs).

You don't have to look at the graphs - the second paragraph in the URL clearly states:

"For those that don't want to read the remaining details nor actually look at the data the shift times likely vary from about 30 to 200 ms."

[YolkyPalky]

Originally Posted by EvenSteven

The transition from one gear to the other with the DCT takes the same amount of time regardless of drivelogic settings. "Higher shifting speed" here means it shifts at higher engine speeds, as in higher RPMs, because it's specifically talking about the D mode.

Directly from the MDCT Manual, page 40:

"In sequential mode the switching speed is affected which has a direct effect on the shifting firmness.

In drive mode the shift points and the shifting speed are affected, as a higher shift program means a higher gear changeover speed and thus a higher shifting speed."

Shift Points - where in RPM range shift initiates
Shifting Speed - how fast the shift takes place
Gear changeover speed - can BMW make it any clearer?

Sounds like you are the one who fails at reading comprehension. Do you even own an M3 DCT? Anyone who does would never argue shift times aren't affected by Drivelogic setting. Try driving 7,000 RPM and downshift in S1 and then in S5, you will feel the difference in gear switching speed.

[llis]

Originally Posted by YolkyPalky

The "M" button doesn't "DO" anything! It is simply a user-defined pre-progammed engine/vehicle settings button. Kind of like when you have your favorite radio station on radio push button #1.

The "M" button is whatever you want it to be. You can set your "M" button to be full on "granny mode" for kids, elderly relatives, or you can set your "M" button to the most aggressive settings possible, it's YOUR choice.

It is simply a "hot button" to recall WHATEVER settings you program it to be.

There is a difference I discovered in having first a 2011 w nav and then a 2013 without: On the 2011, I could set the M button to DSC off. On the 2013, it will NOT save DSC off to the M button settings. I don't know if this is a difference of years, or because of the method of saving the settings.

Or am I missing something?

[EvenSteven]

Originally Posted by YolkyPalky

Directly from the MDCT Manual, page 40:

"In sequential mode the switching speed is affected which has a direct effect on the shifting firmness.

In drive mode the shift points and the shifting speed are affected, as a higher shift program means a higher gear changeover speed and thus a higher shifting speed."

Shift Points - where in RPM range shift initiates
Shifting Speed - how fast the shift takes place
Gear changeover speed - can BMW make it any clearer?

Sounds like you are the one who fails at reading comprehension. Do you even own an M3 DCT? Anyone who does would never argue shift times aren't affected by Drivelogic setting. Try driving 7,000 RPM and downshift in S1 and then in S5, you will feel the difference in gear switching speed.

I can't quite decide whether you're being willfully ignorant or are just stupid. Stop clinging to a quote you don't understand and look at the other material presented in this thread. Have you ever driven anything but an automatic? The difference in feeling has already been addressed and has nothing to do with shift speed.