Calling all tuners! Does the M button manipulate the wastegate duty cycle? - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)

ZCP M3 · 09-28-2012, 12:28 PM

A while back there was an interview with the head of M GmbH on the F10 M5 and he mentioned that in that car as well as the 1M, activating the M button on the steering wheel kept the turbos spooled at an optimum RPM for quicker boost.

So just as the title asks, have you guys seen a different wastegate duty cycle when tuning the 1M with the M button activated? I figured the tuners are the best people to ask since the 1M's high flow downpipes were discovered via lower wastegate duty cycles during some dyno runs.

ozinaldo · 09-28-2012, 01:50 PM

I too am very curious to hear some tuner replies on that. People who actually worked on stock 1Ms intensively, Evolve, GIAC, others.

MDORPHN · 09-28-2012, 02:35 PM

As I understand it, having the M button on closes the wastegates, thereby decreasing spool time and speeding the transition from partial to full throttle.

When the M button is off, the wastegates are open which reduces backpressure/pumping losses and increases efficiency/fuel mileage.

Neil

M3Power79 · 10-02-2012, 06:31 AM

Quote:

Originally Posted by MDORPHN

As I understand it, having the M button on closes the wastegates, thereby decreasing spool time and speeding the transition from partial to full throttle.

When the M button is off, the wastegates are open which reduces backpressure/pumping losses and increases efficiency/fuel mileage.

Neil

That's probably the reason why the exhaust pops like crazy when shifting from 1st to 2nd in normal mode, especialy when the engine is cold.

ZCP M3 · 10-02-2012, 10:29 AM

Quote:

Originally Posted by MDORPHN

As I understand it, having the M button on closes the wastegates, thereby decreasing spool time and speeding the transition from partial to full throttle.

When the M button is off, the wastegates are open which reduces backpressure/pumping losses and increases efficiency/fuel mileage.

Neil

The above is exactly what I'd love to hear confirmation on from those who are balls deep in the DME.

I'm curious if this is true or it's all just more aggressive throttle pedal mapping.

vito747 · 10-21-2012, 06:04 AM

up!
I never drive with M mode on, I like to have more "control" on the gas pedal but if that was the case i would probably drive with M mode on almost all the time.

SDD · 10-21-2012, 09:47 AM

Quote:

Originally Posted by vito747

up!
I never drive with M mode on, I like to have more "control" on the gas pedal but if that was the case i would probably drive with M mode on almost all the time.

Seriously?

This car earns its keep in M mode

Besides the sharper throttle is ideally better for control. Revs build quicker, lag is reduced... I am all for it

bdaddylo · 10-21-2012, 10:58 AM

Quote:

Originally Posted by SDD

Seriously?

This car earns its keep in M mode

Besides the sharper throttle is ideally better for control. Revs build quicker, lag is reduced... I am all for it

It all depends on the driver and where. On the trac, race and autox, it's all about how well you can modulate the throttle and control the boost/torque.

LotusBoy · 10-21-2012, 12:39 PM

Totally agree with the previous post. Until proved otherwise, the M button only changes the throttle pedal mapping. And the last thing you want with that much torque, is a varying throttle response. So I my opinion, it is better to drive with the M button always ON or always OFF. As I drive on the street with DSC in MDM, and track with DSC off, I prefer the more progressive throttle mapping. This means I also always leave the M button OFF !!

nachob · 10-21-2012, 01:01 PM

Im interested too. I think the 1M has enough power already, but quicker throttle response would be a great thing for a tuner to do. I think the M button is fun, but it is touchy and I have tried it both ways and find it too sensitive for my new-to-M-car posterior. I'm learning to manage the torque and traction still and keep the the nose pointed forward. I don't believe touchy throttle gives you better control. If you believe that try heel and toeing with with a Honda Accord's overboosted brakes or the Acura TSX. Even the Blue Angels put stiffer springs on their sticks for better accuracy and control.

ozinaldo · 10-21-2012, 02:08 PM

I am 90 % of the time M button OFF too. It is easier and more natural to manage throttle despite the fact that the lag seems more noticeable in default setting. I also noticed that overboost comes more predictable but then hits sharper in default mode which I like. In fact, what I would like to have is best possible response and least possible lag in non-M mode rather than the M mode. Exhaust mods helped already getting there and now I will add a filter plus a charge pipe and will probably stop there.

///M1 · 10-21-2012, 05:14 PM

Quote:

Originally Posted by nachob

Im interested too. I think the 1M has enough power already, but quicker throttle response would be a great thing for a tuner to do. I think the M button is fun, but it is touchy and I have tried it both ways and find it too sensitive for my new-to-M-car posterior. I'm learning to manage the torque and traction still and keep the the nose pointed forward. I don't believe touchy throttle gives you better control. If you believe that try heel and toeing with with a Honda Accord's overboosted brakes or the Acura TSX. Even the Blue Angels put stiffer springs on their sticks for better accuracy and control.

You don't necessarily need a tune to get improved throttle response/lessen lag, you can achieve so from some bolt-ons. Aftermarket (or N55) midpipes for one, and an appropriately sized FMIC. I say appropriately because too big of an IC can actually worsen lag.

M button = Sprintbooster. I use it most of the time, except for casual driving/in city traffic/congestion, etc. even though it makes the car more 'edgy' with in engaged, I like the on-demand responsiveness.

vito747 · 10-23-2012, 04:33 PM

Quote:

Originally Posted by SDD

Seriously?

This car earns its keep in M mode

Besides the sharper throttle is ideally better for control. Revs build quicker, lag is reduced... I am all for it

Yep, it is all about modulation for me, I find lag to be exactly the same if you push the throttle all the way down...

09-28-2012, 12:28 PM	#1
ZCP M3 First Lieutenant Drives: 2011 VO 1M Coupe #759 Join Date: Jul 2011 Location: St. Louis, MO Posts: 384 iTrader: (0)	Calling all tuners! Does the M button manipulate the wastegate duty cycle? A while back there was an interview with the head of M GmbH on the F10 M5 and he mentioned that in that car as well as the 1M, activating the M button on the steering wheel kept the turbos spooled at an optimum RPM for quicker boost. So just as the title asks, have you guys seen a different wastegate duty cycle when tuning the 1M with the M button activated? I figured the tuners are the best people to ask since the 1M's high flow downpipes were discovered via lower wastegate duty cycles during some dyno runs. Last edited by ZCP M3; 10-02-2012 at 10:30 AM.
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09-28-2012, 01:50 PM	#2
ozinaldo Colonel Drives: 1M Join Date: Jan 2011 Location: Chile, Santiago Posts: 2,163 iTrader: (0)	I too am very curious to hear some tuner replies on that. People who actually worked on stock 1Ms intensively, Evolve, GIAC, others. __________________ 2011 BMW 1M: Euro spec, w/out Nav, manual seats. Evolve Race+N55 mid, Michelin PSS, ER charge pipe, aFe ProDryS drop-in filter, CDVx, BMW-IND trunk spoiler matt cf/VO stripe, BMW blacklines, BMW black grills, IND side gills&rear M logo, silver turn indicator bulbs, anthrazit overlays on side creases and on air curtains, MPerformance steering wheel w/VO ring, BMW steel pedals, custom mats, color matched MPower e-brake.

10-21-2012, 02:08 PM	#11
ozinaldo Colonel Drives: 1M Join Date: Jan 2011 Location: Chile, Santiago Posts: 2,163 iTrader: (0)	I am 90 % of the time M button OFF too. It is easier and more natural to manage throttle despite the fact that the lag seems more noticeable in default setting. I also noticed that overboost comes more predictable but then hits sharper in default mode which I like. In fact, what I would like to have is best possible response and least possible lag in non-M mode rather than the M mode. Exhaust mods helped already getting there and now I will add a filter plus a charge pipe and will probably stop there. __________________ 2011 BMW 1M: Euro spec, w/out Nav, manual seats. Evolve Race+N55 mid, Michelin PSS, ER charge pipe, aFe ProDryS drop-in filter, CDVx, BMW-IND trunk spoiler matt cf/VO stripe, BMW blacklines, BMW black grills, IND side gills&rear M logo, silver turn indicator bulbs, anthrazit overlays on side creases and on air curtains, MPerformance steering wheel w/VO ring, BMW steel pedals, custom mats, color matched MPower e-brake.

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09-28-2012, 02:35 PM	#3
MDORPHN Lieutenant Colonel Drives: AW 1M Join Date: Oct 2010 Location: Wash, DC Posts: 1,833 iTrader: (0)	As I understand it, having the M button on closes the wastegates, thereby decreasing spool time and speeding the transition from partial to full throttle. When the M button is off, the wastegates are open which reduces backpressure/pumping losses and increases efficiency/fuel mileage. Neil

10-21-2012, 06:04 AM	#6
vito747 Private Drives: 1 coupe M Join Date: Jun 2011 Location: Barcelona Posts: 82 iTrader: (0)	up! I never drive with M mode on, I like to have more "control" on the gas pedal but if that was the case i would probably drive with M mode on almost all the time.

10-21-2012, 12:39 PM	#9
LotusBoy Private First Class Drives: BSM 1M, N55, KW's DDC Join Date: Jan 2012 Location: Brussels Posts: 118 iTrader: (0)	Totally agree with the previous post. Until proved otherwise, the M button only changes the throttle pedal mapping. And the last thing you want with that much torque, is a varying throttle response. So I my opinion, it is better to drive with the M button always ON or always OFF. As I drive on the street with DSC in MDM, and track with DSC off, I prefer the more progressive throttle mapping. This means I also always leave the M button OFF !!

10-21-2012, 01:01 PM	#10
nachob Major Drives: 2011 1M Coupe Join Date: Apr 2008 Location: California Posts: 1,051 iTrader: (3)	Im interested too. I think the 1M has enough power already, but quicker throttle response would be a great thing for a tuner to do. I think the M button is fun, but it is touchy and I have tried it both ways and find it too sensitive for my new-to-M-car posterior. I'm learning to manage the torque and traction still and keep the the nose pointed forward. I don't believe touchy throttle gives you better control. If you believe that try heel and toeing with with a Honda Accord's overboosted brakes or the Acura TSX. Even the Blue Angels put stiffer springs on their sticks for better accuracy and control.