[No_curebimmer]

Originally Posted by Marlbombs

Okay so forgive my ignorance, but based on that video earlier in this thread regarding the hyundai, it sounds like ignition timing is altered to create the burbles. Are there any concerns that there may be long term consequences or warranty concerns over essentially changing the engine timing?

Excellent point...yes, I would like to know as well.

For those in the know, for those super-techies...are there any technical issues in removing the exhaust pops and burbles upon deceleration? I'm sure all would agree that we don't want to remove the burbles if they would cause some engine or performance issues.

Just like someone else posted before (the Hyundai vid mentions it as well) - the burbles seem to serve as an 'anti-lag mechanism'. Now, I'm no street nor race-track racer, but I haven't noticed any power issues or turbo lags in my road tests. Erroneously, I thought they were part of 'unburnt fuel in the exhaust manifold'...

P.S. wonder how the Stuttgart engineers achieve maximum performance in their 991.2 or 992 engines without the exhaust burbles.

[Marlbombs]

For the record, im not suggesting this will cause any mechanical problems...but more concerned about it causing warranty issues.

[No_curebimmer]

Originally Posted by Marlbombs

For the record, im not suggesting this will cause any mechanical problems...but more concerned about it causing warranty issues.

Noted!

But it's worth bringing it up: it may seem that the burbles DO indeed serve or have a technical purpose, especially if they relate to engine timing or anti-lag nomenclature. And we'd have to worry about warranty claims IF mechanical issues occur as a result of 'turning off burbles', so they're somewhat related (I know it's a BIG IF).

Despite my true dislike of the burbles, in the spirit of better understanding how the S55 engine works, I would like to pursue this technical conversation.

[Marlbombs]

Originally Posted by No_curebimmer

Wut??? Not sure what he meant by this...are burbles part of a diagnostic mode or something?

I'm wondering if the burbles can be disabled so a tech can hear the engine under load without having the burbles overpowering possible sounds that would indicate mechanical problems?

[JustinHEMI]

I went to almighty google and put in "what purpose do burbles serve for turbo cars" and this was the first thing to come up, some key excerpts;


"Pops and bangs can be attained through many different methods of modification. The main focus is around altering the timing of the car’s ignition map. On most cars, you want the combustion of fuel/air mix to happen just after TDC (Top Dead Centre – where the piston is highest in the cylinder). This means that the piston is only just on it’s way back down to the bottom of the cylinder – an explosion at this point gives it a (pretty significant) helping hand to force the piston down to the bottom of the cylinder as quickly as possible. The exact timing varies from engine to engine, but this is how the ignition is timed to produce maximum power.

Pops and bangs are generated when an explosion echoes in the exhaust. This is either fuel touching the hot exhaust before exploding, or an explosion happening earlier in the system and reverberating through the exhaust. The most common way of achieving this is by retarding the ignition timing so the fuel/air mix ignites later in the engine’s cycle. If timed correctly, the exhaust valve will be opening to allow gas – along with pops and bangs – to escape. This is what most commonly gives you the effect."


"Many modern automatic sports cars will generate a pleasing burble or pop when changing gear – this is achieved in exactly the same way, but not just for the sake of producing that satisfying sound.

In a manual car, you depress the clutch and lift off the accelerator when changing gear. This reduces the load on the gears, allowing them to separate so a new one can be slid into position. In an automatic car, however, you can keep your foot buried in the carpet and flick the “+” paddle until you run out of cogs. This is because when you flick the paddle, the ECU retards (or sometimes cuts entirely) the ignition to reduce the load on the gears for just a split second. As above, this means either some unburnt fuel makes its way to the hot exhaust, or the exhaust port is opening as the explosion occurs in the cylinder."


"Dan was keen to point out that there’s a limit to what is safe. All of that excess fuel and increased temperature isn’t always healthy for your catalytic converter or exhaust. This is kept reasonable when the car is moving with lots of air flowing around keeping things cool (well, cool for an exhaust).

If you’re that kind of reprobate who enjoys redlining their car in front of a crowd at car shows, exercise some caution and keep your popping and banging to a minimum. Luckily though, Dan tells me Litchfield have just the way to control your pops and bangs…"

"Yup. Litchfield have an app that lets you control pretty much any of your car’s functions from your phone, whilst driving. Boost pressure, boost in certain gears, traction control intervention and even the amount your exhaust pops and bangs can all be adjusted in real-time. All hopes of maintaining my poker face vanished at this point. Litchfield has even added features such as rolling launch control, for when you want to thoroughly embarrass non-GTR peasants on the move."



https://drivetribe.com/p/exhaust-pop...Qt6bTnZM37zMyQ



Comments on that article say the same as what's said here, the burbles are sort of an "anti lag" in turbo cars.



The point of sharing that article is that it appears, to me, that there's no danger in turning off the burbles.

[Marlbombs]

yeah, I assumed there wouldnt be any danger from doing so. But are we sure that the only thing being changed in this diagnostic mode is a minor advance to the off throttle ignition timing? This isn't really "disabling burbles" so much as its enabling a diagnostic mode.

[No_curebimmer]

Originally Posted by JustinHEMI

I went to almighty google and put in "what purpose do burbles serve for turbo cars" and this was the first thing to come up, some key excerpts;


"Pops and bangs can be attained through many different methods of modification. The main focus is around altering the timing of the car’s ignition map. On most cars, you want the combustion of fuel/air mix to happen just after TDC (Top Dead Centre – where the piston is highest in the cylinder). This means that the piston is only just on it’s way back down to the bottom of the cylinder – an explosion at this point gives it a (pretty significant) helping hand to force the piston down to the bottom of the cylinder as quickly as possible. The exact timing varies from engine to engine, but this is how the ignition is timed to produce maximum power.

Pops and bangs are generated when an explosion echoes in the exhaust. This is either fuel touching the hot exhaust before exploding, or an explosion happening earlier in the system and reverberating through the exhaust. The most common way of achieving this is by retarding the ignition timing so the fuel/air mix ignites later in the engine’s cycle. If timed correctly, the exhaust valve will be opening to allow gas – along with pops and bangs – to escape. This is what most commonly gives you the effect."


"Many modern automatic sports cars will generate a pleasing burble or pop when changing gear – this is achieved in exactly the same way, but not just for the sake of producing that satisfying sound.

In a manual car, you depress the clutch and lift off the accelerator when changing gear. This reduces the load on the gears, allowing them to separate so a new one can be slid into position. In an automatic car, however, you can keep your foot buried in the carpet and flick the “+” paddle until you run out of cogs. This is because when you flick the paddle, the ECU retards (or sometimes cuts entirely) the ignition to reduce the load on the gears for just a split second. As above, this means either some unburnt fuel makes its way to the hot exhaust, or the exhaust port is opening as the explosion occurs in the cylinder."


"Dan was keen to point out that there’s a limit to what is safe. All of that excess fuel and increased temperature isn’t always healthy for your catalytic converter or exhaust. This is kept reasonable when the car is moving with lots of air flowing around keeping things cool (well, cool for an exhaust).

If you’re that kind of reprobate who enjoys redlining their car in front of a crowd at car shows, exercise some caution and keep your popping and banging to a minimum. Luckily though, Dan tells me Litchfield have just the way to control your pops and bangs…"

"Yup. Litchfield have an app that lets you control pretty much any of your car’s functions from your phone, whilst driving. Boost pressure, boost in certain gears, traction control intervention and even the amount your exhaust pops and bangs can all be adjusted in real-time. All hopes of maintaining my poker face vanished at this point. Litchfield has even added features such as rolling launch control, for when you want to thoroughly embarrass non-GTR peasants on the move."



https://drivetribe.com/p/exhaust-pop...Qt6bTnZM37zMyQ



Comments on that article say the same as what's said here, the burbles are sort of an "anti lag" in turbo cars.



The point of sharing that article is that it appears, to me, that there's no danger in turning off the burbles.

I appreciate you sharing this...

[ebisu8]

I found something I noticed that was slightly different.

When the car is parked, there is a sound when you use the Bimmerlink app to adjust the exhaust flap, from On<->Auto<->Off. Like you can hear the module open/close etc.

Before I did tried the Burble disable - I'd press the M2 button, then go drive from a stop normally, no sound.

After I did turn on the burble disable - I press M2 button, then as soon as I start to drive, I hear the same sound as when I press the button exhaust flap button.

Also, this might sound odd but I think the exhaust is slightly louder without burble disable and performs slightly better than with the burble disabled. Not sure if it is my imagination or not but I do sense a difference. At least enough of a difference for me to mention it.

[CKr]

Originally Posted by ebisu8

I found something I noticed that was slightly different.

When the car is parked, there is a sound when you use the Bimmerlink app to adjust the exhaust flap, from On<->Auto<->Off. Like you can hear the module open/close etc.

Before I did tried the Burble disable - I'd press the M2 button, then go drive from a stop normally, no sound.

After I did turn on the burble disable - I press M2 button, then as soon as I start to drive, I hear the same sound as when I press the button exhaust flap button.

Also, this might sound odd but I think the exhaust is slightly louder without burble disable and performs slightly better than with the burble disabled. Not sure if it is my imagination or not but I do sense a difference. At least enough of a difference for me to mention it.

I noticed some differences as-well, but would like to reserve my comments until I have a chance to drive the car more with burbles on/off. It's rough in California right now, so I'm not even sure if I'll get to drive this weekend, but I'll certainly update the thread when I do get the chance.

[ebisu8]

Originally Posted by Poochie

Bimmerlink disabling burbles, coming soon! https://f80.bimmerpost.com/forums/sh....php?t=1749699

Thanks, if you click back a few pages a few of us already had this before that thread was started, I believe No_curebimmer led the charge on this one.

[No_curebimmer]

Originally Posted by ebisu8

Also, this might sound odd but I think the exhaust is slightly louder without burble disable and performs slightly better than with the burble disabled. Not sure if it is my imagination or not but I do sense a difference. At least enough of a difference for me to mention it.

I more or less know what you mean. In the normal 'stock' mode (burbles ON) it seems everything is louder. However, I can't get over how much the burbles mask whatever is going on under the hood...hard to explain but it's like I want to hear the engine breathe in/out, not be interrupted by the coughing noise of the burbles.

Given @JustinHEMI's findings a few posts above, burbles off don't seem to have any negative effect on the performance or engine per se. So I'll be keeping them off...

[No_curebimmer]

Originally Posted by ebisu8

Thanks, if you click back a few pages a few of us already had this before that thread was started, I believe No_curebimmer led the charge on this one.

Quick update: no issues, no CEL, no loss of power. Once I coded them off, the burbles stayed away.

Not sure if it's too early, as a few of us are still beta testing, but I think we may call this mission accomplished!

[Poochie]

Originally Posted by No_curebimmer

Quick update: no issues, no CEL, no loss of power. Once I coded them off, the burbles stayed away.

Not sure if it's too early, as a few of us are still beta testing, but I think we may call this mission accomplished!

My thing is I need to know if it's like the Bimmerlink ASD disable, where the OBD2 dongle has to remain plugged in, for the bypass to stay active or if the settings retain to the vehicle's memory.

I'll pop the champagne when I know this with certainty.

[No_curebimmer]

Originally Posted by Poochie

My thing is I need to know if it's like the Bimmerlink ASD disable, where the OBD2 dongle has to remain plugged in, for the bypass to stay active or if the settings retain to the vehicle's memory.

I'll pop the champagne when I know this with certainty.

I can confirm that the OBD dongle (Veepeak BLE in my case) doesn't need to remain plugged in.

I basically used it only to turn them off and stowed it away...and they've been off for about 1 week since I got the beta Blink version to test. Never once did I have to replug or reprogram the burbles off.

Thus far, it's been 'set it and forget it' use case.

[Dutch Devotion]

For the S55 this doesn't seem to be an explanation, my 2017 F80M3 had no burbles, and no lag, my 2020M2C has burbles and no lag. The burbles on the S55 have to my opinion nothing to do with anti lag. To be honest, knowing how the torque is limited at low rpm, you cannot really speak about any lag for this engine/turbo setup. I would put my money on keeping cats on temp / emission control measures / snowflakes thinking burbles are cool LOL

By the way, iirc you can also disable the burbles via the AK Motion display. I am still exploring that display and its functionality, which I hobbied in a couple of weeks ago, sofar deeply impressed. Will check next week (when the EL exhaust is on) if I manage to shut down the burbles pops/bangs / farts.

Regards

Erik

[Marlbombs]

I'd still really like to know A) what mechanism the S55 is using to create the burbles in the first place (I.e. what we are turning off) and B) what this diagnostic mode you are enabling does and what its intended use is.

I am just curious if there is some mechanical purpose to it. For instance, maybe it involves extra fuel being injected off throttle to cool the cylinder/valves and the result is the pops. Speculating here obviously, but this isn't like turning off a speaker. This is altering the tuning of the engine somehow.

Maybe this diagnostic mode is actually just whatever is different in the non-comp F80 that doesnt burble? Any tuners out there that would have a way to confirm this?

[Dutch Devotion]

Originally Posted by Marlbombs

I'd still really like to know A) what mechanism the S55 is using to create the burbles in the first place (I.e. what we are turning off) and B) what this diagnostic mode you are enabling does and what its intended use is.

I am just curious if there is some mechanical purpose to it. For instance, maybe it involves extra fuel being injected off throttle to cool the cylinder/valves and the result is the pops. Speculating here obviously, but this isn't like turning off a speaker. This is altering the tuning of the engine somehow.

Maybe this diagnostic mode is actually just whatever is different in the non-comp F80 that doesnt burble? Any tuners out there that would have a way to confirm this?

PTF/Bootmod3 should be able to tell as they offer all kinds of pops nd bangs from absolutely no pops till Hiroshima level and back.

[No_curebimmer]

Originally Posted by Dutch Devotion

For the S55 this doesn't seem to be an explanation, my 2017 F80M3 had no burbles, and no lag, my 2020M2C has burbles and no lag. The burbles on the S55 have to my opinion nothing to do with anti lag. To be honest, knowing how the torque is limited at low rpm, you cannot really speak about any lag for this engine/turbo setup. I would put my money on keeping cats on temp / emission control measures / snowflakes thinking burbles are cool LOL

By the way, iirc you can also disable the burbles via the AK Motion display. I am still exploring that display and its functionality, which I hobbied in a couple of weeks ago, sofar deeply impressed. Will check next week (when the EL exhaust is on) if I manage to shut down the burbles pops/bangs / farts.

Regards

Erik

This further validates that if the F80 platform doesn't have/need the burbles, they serve no purpose for the M2C other than for entertainment value.

[No_curebimmer]

Another brief update: the BimmerLink feature "Sound Tuning" used to turn off the burbles works as intended and designed.

I've been using it for nearly two weeks now - and I've encountered no problems whatsoever!

[Marlbombs]

Originally Posted by No_curebimmer

Another brief update: the BimmerLink feature "Sound Tuning" used to turn off the burbles works as intended and designed.

I've been using it for nearly two weeks now - and I've encountered no problems whatsoever!

Is this still in beta? Can the developer the developer tell you what is happening on the back end when this is enabled/disabled?

[CKr]

Originally Posted by Marlbombs

Is this still in beta? Can the developer the developer tell you what is happening on the back end when this is enabled/disabled?

I asked if he could explain the purpose of this function:

Does BMW have any documentation or explain the purpose of this diagnostic mode [service function]?

Hi,
I can not tell why this service function has been implemented, sorry.

[No_curebimmer]

Originally Posted by Marlbombs

Is this still in beta? Can the developer the developer tell you what is happening on the back end when this is enabled/disabled?

Here is the information that I got from the BimmerLink developer: in the file that describes the ECU functions, BMW themselves call the burble/exhaust pops option "Sound Tuning". Thus, it seems that the only implication is for sound effects, and nothing about turbo spooling or performance related.

Edit: yes, the BimmerLink is still in beta as far as the "Sound Tuning" feature is concerned. Last week I was told it would take him a few weeks to sort everything out.