Exhaust sound affected by temperature?

wuchao1 · 05-11-2010, 12:30 AM

So last night it got really cold here in Michigan about 30 degrees and I just noticed that the sound coming from my exhaust is way different than when it is warm outside, I installed my performance exhaust during winter but somehow I just noticed that now... anyway so does temperature have any affect on how loud the exhaust will be? or making it sound differently? when its cold it sounds like theres something thick covered the exhaust blocking the sound...

jayely1 · 05-11-2010, 12:33 AM

Well your car will usually idle higher when its cold out, so thats one reason why your exhaust is louder..

wuchao1 · 05-11-2010, 12:45 AM

no i mean when im off driving. it sounds different when its cold vs. warm... just wanna know why : )

sole cal · 05-11-2010, 01:42 AM

Ive noticed mine to be quieter when warmer

georgelb · 05-11-2010, 02:11 AM

I would guess it has something to do with sound traveling faster through warm air; cold air blocks sound a bit, which probably accounts for the 'something thick covering the exhaust'.

PiZauL · 05-11-2010, 06:32 AM

I love how it sounds when you just start it up in cold weather, lots of gurgling.. its like music to my ears.

I would imagine once the piping and engine warms up, the sound shouldn't be any different no matter what the temp is. Maybe Geirgelb is onto something. The colder the air, the denser the air is. That causes a greater concentration of oxygen per cubic inch, and the greater the concentration per cubic inch, the higher the fuel/air mixture becomes (more air available to intake). Thus a higher fuel / air mixure yields greater combustion. So this might mean more power/effeciency from the engine resulting in a slightly louder exhaust note? Then again, I dont know shit about fuck, lulz.

MusclezMarinara · 05-11-2010, 11:01 AM

definately louder when colder

Couch · 05-11-2010, 11:06 AM

I think it appears louder b/c when it's colder the air is less dense.

ragingclue · 05-11-2010, 11:08 AM

The air is more dense in cold weather, so sound waves travel more efficiently through the air. With the molecules closer together they have a greater chance of colliding with other molecules to transfer the sound.

Verbiage · 05-11-2010, 07:06 PM

Quote:

Originally Posted by ragingclue

The air is more dense in cold weather, so sound waves travel more efficiently through the air. With the molecules closer together they have a greater chance of colliding with other molecules to transfer the sound.

FrankiE90 · 05-11-2010, 07:47 PM

bmw performance exhaust sounds more aggressive in the cold weather./
i've notice it on mine as well.

Oulixes · 05-11-2010, 08:54 PM

Quote:

Originally Posted by wuchao1

So last night it got really cold here in Michigan about 30 degrees and I just noticed that the sound coming from my exhaust is way different than when it is warm outside, I installed my performance exhaust during winter but somehow I just noticed that now... anyway so does temperature have any affect on how loud the exhaust will be? or making it sound differently? when its cold it sounds like theres something thick covered the exhaust blocking the sound...

ragingclue is right: sound transmission depends on air density. Colder air has greater density than hot air and transmits sound better.

JoshM813 · 05-11-2010, 10:13 PM

Quote:

Originally Posted by ragingclue

The air is more dense in cold weather, so sound waves travel more efficiently through the air. With the molecules closer together they have a greater chance of colliding with other molecules to transfer the sound.

Damn...someone beat me to it...glad to know someone paid attention to physics class haha

ragingclue · 05-12-2010, 09:17 AM

Quote:

Originally Posted by JoshM813

Damn...someone beat me to it...glad to know someone paid attention to physics class haha

Unfortunately for OP, I'm not sure you're even required to go to class at State.

WilliamE92 · 05-12-2010, 09:56 AM

I love cold weather starts even with just a golf tee mod!

Sounds badass, but the loud exhaust novelty wears off quickly IMO and just gets annoying.

wuchao1 · 05-12-2010, 12:03 PM

So it all about air density... never really thought about that. I was thinking more about the temperature on all those metal causing it...

Quote:

Originally Posted by ragingclue

Unfortunately for OP, I'm not sure you're even required to go to class at State.

What Im learning has nothing to do with science at all.. And plus I suck at it.

Couch · 05-12-2010, 02:00 PM

Quote:

Originally Posted by ragingclue

The air is more dense in cold weather, so sound waves travel more efficiently through the air. With the molecules closer together they have a greater chance of colliding with other molecules to transfer the sound.

Duh to myself.

Wasn't thinking about it properly. When you live in humidity, it sure feels more dense.

05-11-2010, 12:30 AM	#1
wuchao1 台北台灣 43 Rep 619 Posts Drives: 2004 MazdaSpeed Miata Join Date: Apr 2009 Location: Michigan State Spartans / Taipei iTrader: (5)	Exhaust sound affected by temperature? So last night it got really cold here in Michigan about 30 degrees and I just noticed that the sound coming from my exhaust is way different than when it is warm outside, I installed my performance exhaust during winter but somehow I just noticed that now... anyway so does temperature have any affect on how loud the exhaust will be? or making it sound differently? when its cold it sounds like theres something thick covered the exhaust blocking the sound... __________________ 2006 E90 325i AT TiAG...Sold! 2000 E39 M5 "The Beast"...Sold! 2004 Mazda Speed Miata... Bone Stock... 2000 Ford Explorer... Beater all the way
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05-11-2010, 12:33 AM	#2
jayely1 Colonel 223 Rep 2,076 Posts Drives: 335i Join Date: Jun 2008 Location: New Mexico/Illinois iTrader: (1)	Well your car will usually idle higher when its cold out, so thats one reason why your exhaust is louder..
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05-11-2010, 12:45 AM	#3
wuchao1 台北台灣 43 Rep 619 Posts Drives: 2004 MazdaSpeed Miata Join Date: Apr 2009 Location: Michigan State Spartans / Taipei iTrader: (5)	no i mean when im off driving. it sounds different when its cold vs. warm... just wanna know why : ) __________________ 2006 E90 325i AT TiAG...Sold! 2000 E39 M5 "The Beast"...Sold! 2004 Mazda Speed Miata... Bone Stock... 2000 Ford Explorer... Beater all the way
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05-11-2010, 01:42 AM	#4
sole cal Black Mamba 66 Rep 1,326 Posts Drives: E90 335i Join Date: Jul 2008 Location: SoCal 818 iTrader: (10)	Ive noticed mine to be quieter when warmer __________________ www.ticketbeaters.com
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05-11-2010, 02:11 AM	#5
georgelb nsomneeak 39 Rep 501 Posts Drives: E92 RB 335i Join Date: Apr 2010 Location: DFW, TX iTrader: (3) Garage List 2007 335i [8.00]	I would guess it has something to do with sound traveling faster through warm air; cold air blocks sound a bit, which probably accounts for the 'something thick covering the exhaust'.
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05-11-2010, 06:32 AM	#6
PiZauL I6 + TT = FTW 84 Rep 849 Posts Drives: E90 M3, GT350, Tesla M3P Join Date: Jan 2010 Location: Baltimore, MD iTrader: (2)	I love how it sounds when you just start it up in cold weather, lots of gurgling.. its like music to my ears. I would imagine once the piping and engine warms up, the sound shouldn't be any different no matter what the temp is. Maybe Geirgelb is onto something. The colder the air, the denser the air is. That causes a greater concentration of oxygen per cubic inch, and the greater the concentration per cubic inch, the higher the fuel/air mixture becomes (more air available to intake). Thus a higher fuel / air mixure yields greater combustion. So this might mean more power/effeciency from the engine resulting in a slightly louder exhaust note? Then again, I dont know shit about fuck, lulz. Last edited by PiZauL; 05-11-2010 at 07:38 AM..
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05-11-2010, 11:01 AM	#7
MusclezMarinara Banned 262 Rep 5,018 Posts Drives: VALNCYA Join Date: Jan 2009 Location: Jersey iTrader: (23) Garage List 2011 BMW 1M [9.22] 2009 335i Sedan xdrive [9.34]	definately louder when colder
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05-11-2010, 11:06 AM	#8
Couch Colonel 142 Rep 2,900 Posts Drives: E92 335i Join Date: Jan 2007 Location: Houston iTrader: (0) Garage List 2007 E92 335i [0.00]	I think it appears louder b/c when it's colder the air is less dense.
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05-11-2010, 11:08 AM	#9
ragingclue One cam is enough 130 Rep 6,801 Posts Drives: VF Join Date: Oct 2008 Location: mulletville iTrader: (1)	The air is more dense in cold weather, so sound waves travel more efficiently through the air. With the molecules closer together they have a greater chance of colliding with other molecules to transfer the sound.
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05-11-2010, 07:47 PM	#11
FrankiE90 Major General 654 Rep 8,801 Posts Drives: Krooked Sk8board Join Date: Feb 2008 Location: Pasadena, Ca iTrader: (11)	bmw performance exhaust sounds more aggressive in the cold weather./ i've notice it on mine as well. __________________ FrankiE90 AKA:.[The TANK] *CLICK THE SIG E90s (been gone but not forgotten) • KW clubsports • • • • • • • • • • 18" BBS GT4 // Build E30 (pending) + E46 M3 Wagon ESTORIL Blue
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05-12-2010, 09:56 AM	#15
WilliamE92 First Lieutenant 21 Rep 318 Posts Drives: 2013 EB F30 335 MT Join Date: Aug 2009 Location: CA iTrader: (1)	I love cold weather starts even with just a golf tee mod! Sounds badass, but the loud exhaust novelty wears off quickly IMO and just gets annoying.
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