Gurgles, pops and SNAPS ... OH MY!

Horseman · 11-30-2023, 02:13 PM

Alright, so we all know that the M40i makes alot more gurgly poppy noises than the 30i, but considering how new this is to me, it is still a bit of a wow factor.

Today I was in Sport Plus and downshifting as I was coming up to a red light. Poor lady was walking on the cross walk when I downshifted into first to only be met with a loud SNAP!! that sounded like a whip crack. Needless to say I was very stunned myself to hear that especially since it was at only maybe... 4.5k rpm.

Now... why a new thread.. well I don't recall the car ever being that SNAPPY when I first picked it up, so is this something that will keep on going as the engine gets more worn in?

MisanoblueZ4 · 11-30-2023, 02:40 PM

Quote:

Originally Posted by Horseman

Alright, so we all know that the M40i makes alot more gurgly poppy noises than the 30i, but considering how new this is to me, it is still a bit of a wow factor.

Today I was in Sport Plus and downshifting as I was coming up to a red light. Poor lady was walking on the cross walk when I downshifted into first to only be met with a loud SNAP!! that sounded like a whip crack. Needless to say I was very stunned myself to hear that especially since it was at only maybe... 4.5k rpm.

Now... why a new thread.. well I don't recall the car ever being that SNAPPY when I first picked it up, so is this something that will keep on going as the engine gets more worn in?

Mine has 13.5k on it and snap crackle pops significantly with Plus mode shifting programming, especially when coming to a stop and the higher revs are coming down in each gear change.

I have my Sport Individual programmed to (Sport) transmission as I feel it is a nice balance of revs/shift with less pops and bangs coming to a stop.

Horseman · 11-30-2023, 02:45 PM

With my 30i I was thinking of replacing my stock exhaust system with something a little louder but I didn't want the BANG BANG BANG annoyance. Don't need it sounding like a gun.

It was clear that I startled the person that was walking in the cross walk when I downshifted and it SNAPPED, and I had no intention of doing so. Hell, it surprised me! I know it gurgles and pops alot more like... ALOT MORE, but the really loud ones get me sometimes lol

MisanoblueZ4 · 11-30-2023, 03:15 PM

Quote:

Originally Posted by Horseman

With my 30i I was thinking of replacing my stock exhaust system with something a little louder but I didn't want the BANG BANG BANG annoyance. Don't need it sounding like a gun.

It was clear that I startled the person that was walking in the cross walk when I downshifted and it SNAPPED, and I had no intention of doing so. Hell, it surprised me! I know it gurgles and pops alot more like... ALOT MORE, but the really loud ones get me sometimes lol

Around here a factory Z4 M40i exhaust is very tame lol. Most trucks are MUCH louder, never mind the Mustang/Chargers/Camaro.

GerryC · 11-30-2023, 03:28 PM

Quote:

Originally Posted by MisanoblueZ4

Around here a factory Z4 M40i exhaust is very tame lol. Most trucks are MUCH louder, never mind the Mustang/Chargers/Camaro.

I've got a Camaro, Mustang, and a modified Corvette that drive by regularly. They're loud, but the loudest is the Harley.

Balr14 · 12-01-2023, 10:06 AM

Quote:

Originally Posted by GerryC

I've got a Camaro, Mustang, and a modified Corvette that drive by regularly. They're loud, but the loudest is the Harley.

I live in the Milwaukee area. The Harley plant is about 4 miles away. Several of them live across the street from me. My son-in-law and grandson own Harleys. In the summer, you can't swing a dead cat around here without hitting a Harley. Makes me glad to be hearing impaired!

alvitdk · 12-01-2023, 12:09 PM

Quote:

Originally Posted by Horseman

With my 30i I was thinking of replacing my stock exhaust system with something a little louder but I didn't want the BANG BANG BANG annoyance. Don't need it sounding like a gun.

It was clear that I startled the person that was walking in the cross walk when I downshifted and it SNAPPED, and I had no intention of doing so. Hell, it surprised me! I know it gurgles and pops alot more like... ALOT MORE, but the really loud ones get me sometimes lol

I fully agree and I remedied the situation by setting it in Sport Individual to "Comfort" setting and installed the Denin throttle booster to make up for the slower throttle response. Everything else is set to sport. Now it behaves like in sport mode (Or sport plus depending on the setting on the fly) but with way less burbles and bangs.

CJ421 · 12-01-2023, 02:43 PM

I've had an unusually loud pop/snap on downshifts a couple times since I've owned the car - I don't think BMW intends it to be that loud i.e., it's a glitch.

But this car definitely creates some noise. I personally love how animated it can be while downshifting. It sounds better than the inline-6 M cars. Truly a fantastic exhaust - and it's stock!

Charles

Horseman · 12-02-2023, 06:55 AM

Quote:

Originally Posted by CJ421

I've had an unusually loud pop/snap on downshifts a couple times since I've owned the car - I don't think BMW intends it to be that loud i.e., it's a glitch.

But this car definitely creates some noise. I personally love how animated it can be while downshifting. It sounds better than the inline-6 M cars. Truly a fantastic exhaust - and it's stock!

Charles

Yeah a security guard at my kid's school was very very surprised that this was a stock exhaust. He came to talk to me and was wondering what kind of exhaust system I had and I'm like... No idea.. it's stock. lol and then demonstrated it for him. Gave a couple baby revs and you can definitely tell it melted his heart a little.

stlcdr · 12-02-2023, 08:18 AM

I don't find them particularly loud, but it's a fun sound. Sometimes I wish sport mode was a little less, ahem, 'sporty'. (Not really).

I had an old fiat spider ('82) that you could get to gurgle by giving it a tad of throttle to put gas in the cylinders while slowing down under engine braking (I'm assuming this is how it's done).

perryinva · 12-02-2023, 08:54 AM

I thought all the pops and gurgles were from ASD? I know (well pretty sure) in my 3.0 that once I turned off ASD, they all went away. Have any of you with the loud pops etc turned off ASD?

CJ421 · 12-02-2023, 10:22 AM

Quote:

Originally Posted by perryinva

I thought all the pops and gurgles were from ASD? I know (well pretty sure) in my 3.0 that once I turned off ASD, they all went away. Have any of you with the loud pops etc turned off ASD?

I don't think it's ASD. The effect is quite pronounced with the top down.

Charles

dholaday · 12-02-2023, 11:39 AM

Quote:

Originally Posted by perryinva

I thought all the pops and gurgles were from ASD? I know (well pretty sure) in my 3.0 that once I turned off ASD, they all went away. Have any of you with the loud pops etc turned off ASD?

How do you turn ASD off?

Thanks

StanDiego · 12-02-2023, 12:52 PM

Quote:

Originally Posted by perryinva

I thought all the pops and gurgles were from ASD? I know (well pretty sure) in my 3.0 that once I turned off ASD, they all went away. Have any of you with the loud pops etc turned off ASD?

I'm not sure it's completely gone but certainly greatly diminished (even in sport mode) in my s30i after disabling ASD.

MisanoblueZ4 · 12-02-2023, 01:29 PM

Quote:

Originally Posted by StanDiego

I'm not sure it's completely gone but certainly greatly diminished (even in sport mode) in my s30i after disabling ASD.

I was under the impression ASD was played through the speakers? Does removing ASD change the external exhaust tone as well?

StanDiego · 12-02-2023, 02:40 PM

Quote:

Originally Posted by MisanoblueZ4

I was under the impression ASD was played through the speakers? Does removing ASD change the external exhaust tone as well?

No, it doesn’t change the external exhaust tone. Only the control flap on the exhaust will change the sound of the exhaust output.
A little bit of unburnt fuel in the exhaust will give you the burble but I don’t know if/how BMW programs that into the fuel maps or not.

ImActuallyAParrotNotHuman · 12-02-2023, 10:02 PM

If you want louder bangs without modifying stock exhausts in any way whether by modifying, adding,or removing parts, get a tune so you can use E85. I've been adding 33% e85 always, on a custom tune. Much louder bangs and it's like a new car the acceleration is massive. B58 has so much potential

vertigo corsa · 12-03-2023, 01:18 PM

Quote:

Originally Posted by StanDiego

...I don’t know if/how BMW programs that into the fuel maps or not.

Its intentionally coded into the tune.

The usual way of achieving this is by retarding timing in the vehicle's ignition mapping, causing a portion of the unburnt fuel/air mix to combust from the heat of the exhaust instead. Those sounds reverberate through your pipes after the power stroke, causing the resulting pops, bangs, and burbles.

StanDiego · 12-03-2023, 04:58 PM

Quote:

Originally Posted by vertigo corsa

Its intentionally coded into the tune.

The usual way of achieving this is by retarding timing in the vehicle's ignition mapping, causing a portion of the unburnt fuel/air mix to combust from the heat of the exhaust instead. Those sounds reverberate through your pipes after the power stroke, causing the resulting pops, bangs, and burbles.

Correct. I know how it can be done but I don't know specifically how BMW currently achieves it.

perryinva · 12-03-2023, 11:49 PM

ASD has to be coded off with software, like Bimmercode, which uses your phone (or tablet) and a BT dongle that plugs in to the OBDII port. I know the 6 has more burble than the 4, I just don’t know how much is fake and how much is real. There is very little in the 4, with ASD OFF. Even top down, with ASD ON, it is quite real sounding, with the either stock stereo.

But add a DSP amp and the ASD becomes annoyingly loud and fake sounding (for me, of course, others may like it enhanced)

Balr14 · 12-04-2023, 02:24 PM

I may be imagining this, as I don't hear very well, but it seems to me the popping is less when in Sport Plus and manual mode than when just in Sport Plus.

Horseman · 12-04-2023, 07:44 PM

Quote:

Originally Posted by Balr14

I may be imagining this, as I don't hear very well, but it seems to me the popping is less when in Sport Plus and manual mode than when just in Sport Plus.

Honestly.... i never am in sport plus and NOT in manual mode.

11-30-2023, 02:13 PM	#1
Horseman Colonel 4132 Rep 2,494 Posts Drives: 2024 BMW Z4 M40i Join Date: May 2021 Location: Texas iTrader: (0) Garage List 2024 BMW Z4 M40i [9.90]	Gurgles, pops and SNAPS ... OH MY! Alright, so we all know that the M40i makes alot more gurgly poppy noises than the 30i, but considering how new this is to me, it is still a bit of a wow factor. Today I was in Sport Plus and downshifting as I was coming up to a red light. Poor lady was walking on the cross walk when I downshifted into first to only be met with a loud SNAP!! that sounded like a whip crack. Needless to say I was very stunned myself to hear that especially since it was at only maybe... 4.5k rpm. Now... why a new thread.. well I don't recall the car ever being that SNAPPY when I first picked it up, so is this something that will keep on going as the engine gets more worn in? __________________ Retired: 2021 BMW Z4 sDrive 30i - Alpine White/Magma Red
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11-30-2023, 02:45 PM	#3
Horseman Colonel 4132 Rep 2,494 Posts Drives: 2024 BMW Z4 M40i Join Date: May 2021 Location: Texas iTrader: (0) Garage List 2024 BMW Z4 M40i [9.90]	With my 30i I was thinking of replacing my stock exhaust system with something a little louder but I didn't want the BANG BANG BANG annoyance. Don't need it sounding like a gun. It was clear that I startled the person that was walking in the cross walk when I downshifted and it SNAPPED, and I had no intention of doing so. Hell, it surprised me! I know it gurgles and pops alot more like... ALOT MORE, but the really loud ones get me sometimes lol __________________ Retired: 2021 BMW Z4 sDrive 30i - Alpine White/Magma Red
	Appreciate 1 MisanoblueZ41374.50 Quote

12-01-2023, 02:43 PM	#8
CJ421 Brigadier General 1559 Rep 4,109 Posts Drives: BMW M3 Join Date: Feb 2011 Location: Blue Bell, PA iTrader: (1) Garage List 2024 BMW M3 Sedan [9.50]	I've had an unusually loud pop/snap on downshifts a couple times since I've owned the car - I don't think BMW intends it to be that loud i.e., it's a glitch. But this car definitely creates some noise. I personally love how animated it can be while downshifting. It sounds better than the inline-6 M cars. Truly a fantastic exhaust - and it's stock! Charles __________________ 2024 BMW M3 Sedan Frozen Pure Grey II/Fjord Blue, 6MT Past: 2021 Z4 M40i Frozen Grey II/Black Alcantara \| 2017 F30 340i Mineral Gray/Coral Red, 6MT \| 2011 E92 335i Le Mans Blue/Black, 6MT
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12-02-2023, 08:18 AM	#10
stlcdr Captain 1015 Rep 681 Posts Drives: 2022 Z4 M40i Join Date: Feb 2022 Location: Kentucky iTrader: (0)	I don't find them particularly loud, but it's a fun sound. Sometimes I wish sport mode was a little less, ahem, 'sporty'. (Not really). I had an old fiat spider ('82) that you could get to gurgle by giving it a tad of throttle to put gas in the cylinders while slowing down under engine braking (I'm assuming this is how it's done). __________________ 2022 BMW Z4 M40i \| 2021 HD Road Glide Limited \| 2019 Ford Expedition XLT MAX \| Subaru Outback 2019 \| Subaru Outback 2024
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12-02-2023, 08:54 AM	#11
perryinva Private First Class 123 Rep 161 Posts Drives: 2022 Z4S30i 2019 X3x30i Join Date: Aug 2023 Location: Richmond, VA iTrader: (0)	I thought all the pops and gurgles were from ASD? I know (well pretty sure) in my 3.0 that once I turned off ASD, they all went away. Have any of you with the loud pops etc turned off ASD?
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12-02-2023, 10:02 PM	#17
ImActuallyAParrotNotHuman Enlisted Member 71 Rep 41 Posts Drives: Z4 (M40i), prev M235 M2C M4 Join Date: Nov 2023 Location: Malibu iTrader: (0)	If you want louder bangs without modifying stock exhausts in any way whether by modifying, adding,or removing parts, get a tune so you can use E85. I've been adding 33% e85 always, on a custom tune. Much louder bangs and it's like a new car the acceleration is massive. B58 has so much potential
	Appreciate 0 Quote

12-03-2023, 11:49 PM	#20
perryinva Private First Class 123 Rep 161 Posts Drives: 2022 Z4S30i 2019 X3x30i Join Date: Aug 2023 Location: Richmond, VA iTrader: (0)	ASD has to be coded off with software, like Bimmercode, which uses your phone (or tablet) and a BT dongle that plugs in to the OBDII port. I know the 6 has more burble than the 4, I just don’t know how much is fake and how much is real. There is very little in the 4, with ASD OFF. Even top down, with ASD ON, it is quite real sounding, with the either stock stereo. But add a DSP amp and the ASD becomes annoyingly loud and fake sounding (for me, of course, others may like it enhanced)
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12-04-2023, 02:24 PM	#21
Balr14 Lieutenant 559 Rep 400 Posts Drives: 2020 Z4 M40i Join Date: Mar 2019 Location: Menomonee Falls, Wi. iTrader: (0)	I may be imagining this, as I don't hear very well, but it seems to me the popping is less when in Sport Plus and manual mode than when just in Sport Plus.
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