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I was on Instagram and saw this guys E39 M5. He somehow has a burble tune or something that has the pops and bangs when lifting off the throttle. Anyone know how to do this? I know you can tune it in on modern cars,
but how did he do it on an E39? Could it be potentially bad for the engine? I used to have an F80 M3 that did this and I miss those pops, I know some people think it’s dumb, but i think it sounds cool.

https://www.instagram.com/p/BxBHubjA7xn/?igshid=onc0olzbwben
 

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The MSS54 project pretty much documented this whole thing, basically you need to over run the injector a little bit after cut off. It's not hard it's really just a few map edits, and googling the right map. I never had much interest so that's all I know, but the info is out there.
 

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If your F80 did that is was broken also. If that car is running a stock tune it is also broken. In the long term it will not be good but hard to say bad either, just depends.
If you want to do that just imitate what is broken, 1/2 the clutch switch. Two parts to a clutch switch one for starting and one to know that you pushed in the clutch so it will supply fuel to the injectors so the car does not stall when you are off the gas. One switch works at the top of the pedal the other at the bottom.

All you need to do is remove one wire and you can guess at it if you want pull any that go to the starter part car won't start any of the others are fine.
 

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I used to have an F80 M3 that did this in stock form. Should I have bought a honda civic instead?


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Mfg's do this on newer performance cars because people think its trendy and cool. Its just artificial how forced it is these days.
 

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If your F80 did that is was broken also. If that car is running a stock tune it is also broken. In the long term it will not be good but hard to say bad either, just depends.
If you want to do that just imitate what is broken, 1/2 the clutch switch. Two parts to a clutch switch one for starting and one to know that you pushed in the clutch so it will supply fuel to the injectors so the car does not stall when you are off the gas. One switch works at the top of the pedal the other at the bottom.

All you need to do is remove one wire and you can guess at it if you want pull any that go to the starter part car won't start any of the others are fine.


Pretty sure my F80 that I bought brand new wasn’t broken. It was bone stock. The burbles and pops are part of the competition package.


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I have not heard one do it and it is part of emissions requirements to turn off fuel on decel for all new cars since IIRC 98. Maybe it was fake sound from the audio.
 

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I have not heard one do it and it is part of emissions requirements to turn off fuel on decel for all new cars since IIRC 98. Maybe it was fake sound from the audio.
It's not emissions decel with the S55 tuning...not at all unfortunately. The S55 in my M2C when in Sport or Sport+ mode is full of pops, burbles and crackles on the over-run. Outside the car it is fairly loud but well integrated into the exhaust sound; let one go by you at full throttle in 2nd and then abruptly lifts off throttle at about 5k rpms....loud ripping tear followed by burbles. Put it in Comfort mode, and all is much quieter and all those shenanigans are gone.

As to the other subject about fuel cut-off on closed throttle...that first appeared with Bosch Motronic in 1982 on the M20 in the 528e (in North America) and then in the M30 and others. Hence all BMWs from E28 onward essentially have fuel cutoff on closed throttle (above a preset rpm, usually about 1400). 37 years now.
 
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If your F80 did that is was broken also. If that car is running a stock tune it is also broken. In the long term it will not be good but hard to say bad either, just depends.
If you want to do that just imitate what is broken, 1/2 the clutch switch. Two parts to a clutch switch one for starting and one to know that you pushed in the clutch so it will supply fuel to the injectors so the car does not stall when you are off the gas. One switch works at the top of the pedal the other at the bottom.

All you need to do is remove one wire and you can guess at it if you want pull any that go to the starter part car won't start any of the others are fine.
Competition Package S55 motors do it from the factory, with nothing wrong with them.
Pretty sure my F80 that I bought brand new wasn’t broken. It was bone stock. The burbles and pops are part of the competition package.


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Exactly. 2017 F80 Competition Pack here and it snaps crackles and pops from the factory at 4500-6000rpms upon letting up on the gas.
 

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My car does this (though not as loud) after installing my x-pipe and exhaust. While it typically only happens when letting off the throttle at certain RPM ranges, you can re-create it by letting off the throttle, and tapping the throttle pedal with your foot. Not enough to propel you forward, but enough to send fuel to be burbled off. I very much dislike all the pops on so many cars these days as it seems you hear the machine gun pops on so many cars if you sit and watch cars go by on a busy road.
 

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I used to have an F80 M3 that did this in stock form. Should I have bought a honda civic instead?


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I'm pretty sure F80 m3 doesn't just dump fuel into the exhaust on overrun, because that's what' that e39 is doing. Turbo anti lag, except without a turbo...
 

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Well that is getting into another area and it is from fuel being left in the head sitting on the valves when you let off the gas. At full throttle your injector duty cycle is 95% likely. That is a ton of fuel at 5k or 6k rpm. The S62 burbles a bit at 6k when you come of the gas. My RS4 with two turbos added and 2 sizes up on injectors burbles for a very long time, because of all the fuel being dumped in for all that air I push through at 6k. It is atomized above the valve, it is not like it pours in like a tap.

When I come off the gas the air is reduced to nothing from 15 psi and just drags a little of that fuel into the cyl each pass. I can stop the burble by hitting the gas just a bit for a second or two.
Anyway my comment was based on the video, not full throttle at high rpms. If people want to take it out of context so be it.
Yes I recognize many manufacturers shut fuel off on decel much earlier but the point was it became law and there is no getting around that, so BMW is not adding fuel on decel so guys can hear their cars burble so they sell more cars.
 

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It's not emissions decel with the S55 tuning...not at all unfortunately. The S55 in my M2C when in Sport or Sport+ mode is full of pops, burbles and crackles on the over-run. Outside the car it is fairly loud but well integrated into the exhaust sound; let one go by you at full throttle in 2nd and then abruptly lifts off throttle at about 5k rpms....loud ripping tear followed by burbles. Put it in Comfort mode, and all is much quieter and all those shenanigans are gone.

As to the other subject about fuel cut-off on closed throttle...that first appeared with Bosch Motronic in 1982 on the M20 in the 528e (in North America) and then in the M30 and others. Hence all BMWs from E28 onward essentially have fuel cutoff on closed throttle (above a preset rpm, usually about 1400). 37 years now.
Correct. Standard on the competition packages. The big aftermarket tuning platforms (Bootmod3, Apline, MHD etc) all add this. Bootmod actually allow the user to modify burbles to his/her taste. Personally, I think it sounds ricey and turned them off in my F82. To each their own


Brian
 

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I used to have an F80 M3 that did this in stock form. Should I have bought a honda civic instead?


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Well, exhaust sound on F80 is computer generated soundtrack that comes through the speakers anyway, so you could do what ever sound you want, really. J/k, but I do find F80 exhaust sound super lame.
 

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Well, exhaust sound on F80 is computer generated soundtrack that comes through the speakers anyway, so you could do what ever sound you want, really. J/k, but I do find F80 exhaust sound super lame.
LOL. Thats why so many decat and do cartwheels trying to get rid of the Fart Can sound of the inline 6 LOL It is sSUCH a great engine though despite its sound
 
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