Exhaust Burble Questions

CurtisP87 · 02-14-2018, 02:14 PM

The upcoming MHD update had me wondering some things about exhaust burbles....mainly, what is it?

Here's how I understand it, someone correct me if I'm wrong: Extra fuel is injected into the cylinders during the exhaust stroke, which allows unburnt fuel into the exhaust system where it's detonated by the heat of the exhaust gases. These tiny "controlled" explosions in the exhaust piping are the burbles/pops/cracks we all (most of us) love.

Is that correct? If it is correct, then does increasing the intensity of these burbles just mean injecting more extra fuel? How much extra are we talking about (read: how big of a hit will my gas consumption take if I'm driving around banging and popping everywhere)? Are there any negative side effects over the long term of having these explosions in the exhaust system?

Finally, whats the origin of these exhaust noises? I feel like it must have started with WRC cars, but maybe it goes back further than that....What caused the pops/crackles on those cars? Surely professional race car tuners weren't bothered to code little "tricks" just to make some extra noise the way we have to with our street cars.

joeinsd · 02-14-2018, 03:11 PM

There's already lots of debate out there (just search) on whether the burbles have any negative side affects or not. Depends on who you talk to, and there hasn't been any real data out there to back it up. Some turbo companies have come out to say that if you use burble, your warranty will be void.

For a good amount of time, I used it with Medium for 1.5 secs, but have disabled for about 6 months now and I feel that the car drives better without. With it enabled, I felt the car was a bit on the jerky side. Aside from that, I didn't see any other issues really (ie smoking, etc.) Everyone will have their different experiences and opinions with it.

CurtisP87 · 02-14-2018, 03:37 PM

I've been running the burble with MHD for a while now, haven't noticed any impact on how the car runs...But, I've got an AT, so if I don't wanna hear it I can just throw it in D and forget that it's there...

With all the hype about the coming update and increased intensity, I was just curious about what's actually happening in the engine/exhaust.

dleccord · 02-15-2018, 03:17 AM

Quote:

Originally Posted by CurtisP87

I've been running the burble with MHD for a while now, haven't noticed any impact on how the car runs...But, I've got an AT, so if I don't wanna hear it I can just throw it in D and forget that it's there...

With all the hype about the coming update and increased intensity, I was just curious about what's actually happening in the engine/exhaust.

can you comment on your mpg?

CurtisP87 · 02-15-2018, 08:18 PM

Quote:

Originally Posted by dleccord

can you comment on your mpg?

I honestly don't pay much attention to it...lol

My mileage isn't great, though, if I'm having fun in it. If I'm just cruising at a relaxed pace, I think I hover around 20-22 mpg.

02-14-2018, 02:14 PM	#1
CurtisP87 Enlisted Member 4 Rep 30 Posts Drives: 2011 335xi Alpine White Join Date: Sep 2016 Location: Portland, OR iTrader: (0)	Exhaust Burble Questions The upcoming MHD update had me wondering some things about exhaust burbles....mainly, what is it? Here's how I understand it, someone correct me if I'm wrong: Extra fuel is injected into the cylinders during the exhaust stroke, which allows unburnt fuel into the exhaust system where it's detonated by the heat of the exhaust gases. These tiny "controlled" explosions in the exhaust piping are the burbles/pops/cracks we all (most of us) love. Is that correct? If it is correct, then does increasing the intensity of these burbles just mean injecting more extra fuel? How much extra are we talking about (read: how big of a hit will my gas consumption take if I'm driving around banging and popping everywhere)? Are there any negative side effects over the long term of having these explosions in the exhaust system? Finally, whats the origin of these exhaust noises? I feel like it must have started with WRC cars, but maybe it goes back further than that....What caused the pops/crackles on those cars? Surely professional race car tuners weren't bothered to code little "tricks" just to make some extra noise the way we have to with our street cars.
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02-14-2018, 03:11 PM	#2
joeinsd Captain 288 Rep 899 Posts Drives: Stock 2010 e92 335i M Sport Join Date: Apr 2015 Location: San Diego iTrader: (9)	There's already lots of debate out there (just search) on whether the burbles have any negative side affects or not. Depends on who you talk to, and there hasn't been any real data out there to back it up. Some turbo companies have come out to say that if you use burble, your warranty will be void. For a good amount of time, I used it with Medium for 1.5 secs, but have disabled for about 6 months now and I feel that the car drives better without. With it enabled, I felt the car was a bit on the jerky side. Aside from that, I didn't see any other issues really (ie smoking, etc.) Everyone will have their different experiences and opinions with it.
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02-14-2018, 03:37 PM	#3
CurtisP87 Enlisted Member 4 Rep 30 Posts Drives: 2011 335xi Alpine White Join Date: Sep 2016 Location: Portland, OR iTrader: (0)	I've been running the burble with MHD for a while now, haven't noticed any impact on how the car runs...But, I've got an AT, so if I don't wanna hear it I can just throw it in D and forget that it's there... With all the hype about the coming update and increased intensity, I was just curious about what's actually happening in the engine/exhaust.
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