Exhaust @ cold start

caman · 07-22-2017, 01:31 PM

Apologies in advance to the many who have taken time to post on the various Exhaust threads but I'm looking for relatively basic info.

My M2 sounds great on cold startup but something changes around 20-30 seconds after startup. Placing in Sport + mode doesn't seem to make a difference.

My question is whether there is a way to keep the cold startup sound 20-30 seconds after startup.

I am running a stock exhaust system.

Thanks.

mrcheezle19 · 07-22-2017, 01:48 PM

No, that is the engine cold starting and as the idle dies down the sound goes away. I guess you could unlock the ECU and have the idle rpm changed and fueling, but realistically just get an exhaust or downpipe. I'll sell you my GThaus exhaust. It's nasty all the time lol.

kiysersosae · 07-22-2017, 01:49 PM

Quote:

Originally Posted by caman

Apologies in advance to the many who have taken time to post on the various Exhaust threads but I'm looking for relatively basic info.

My M2 sounds great on cold startup but something changes around 20-30 seconds after startup. Placing in Sport + mode doesn't seem to make a difference.

My question is whether there is a way to keep the cold startup sound 20-30 seconds after startup.

I am running a stock exhaust system.

Thanks.

A sound clip would be good?

There is no way you can keep that sound after the engine and exhaust begin to heat up and expand . fuel will be reduced into the cylinders as the car warms and normal service will resume.

caman · 07-22-2017, 01:54 PM

Understand but the change I'm hearing is a not gradual change but a distinct step change like a valve is opening or closing - about 20-30 seconds after a cold start.

kiysersosae · 07-22-2017, 02:01 PM

Quote:

Originally Posted by caman

Understand but the change I'm hearing is a not gradual change but a distinct step change like a valve is opening or closing - about 20-30 seconds after a cold start.

I have the MPE perf exhaust and can't hear much until after 10 seconds. The only thing I can think are the valve lifters, is to do with helping catalytic convertor heat up cycle.

ZPrime · 07-22-2017, 05:33 PM

Secondary air injection. it's for emissions. heats the cat quicker.

NO_USER_ · 07-22-2017, 07:18 PM

I'm selling my Remus Exhaust, it'll give you a nice start up sound! Brand new tips, and only about 35 miles on the exhaust.

DoggieHowser · 07-22-2017, 08:01 PM

The missus is complaining that when the M2 starts up in the garage, which shares a wall with the kitchen where we hang all our cooking utensils, everything is clanging and vibrating. It's going to be mad as hell when I get the M Performance exhaust installed

Artemis · 07-22-2017, 09:40 PM

Quote:

Originally Posted by DoggieHowser

The missus is complaining that when the M2 starts up in the garage, which shares a wall with the kitchen where we hang all our cooking utensils, everything is clanging and vibrating. It's going to be mad as hell when I get the M Performance exhaust installed

BAN_M2C · 07-24-2017, 04:29 PM

Like this?

https://instagram.com/p/BW6KybflOeh/

mike@x-ph.com · 07-24-2017, 06:04 PM

Quote:

Originally Posted by caman

Apologies in advance to the many who have taken time to post on the various Exhaust threads but I'm looking for relatively basic info.

My M2 sounds great on cold startup but something changes around 20-30 seconds after startup. Placing in Sport + mode doesn't seem to make a difference.

My question is whether there is a way to keep the cold startup sound 20-30 seconds after startup.

I am running a stock exhaust system.

Thanks.

As mentioned, cold start tone is always higher.

You can get an upgraded exhaust system for a more aggressive sound

kab_m2 · 07-24-2017, 06:50 PM

Quote:

Originally Posted by caman

Understand but the change I'm hearing is a not gradual change but a distinct step change like a valve is opening or closing - about 20-30 seconds after a cold start.

There is a baffle that's controlled by an actuator in the exhaust, usually on one side. The valve closes on a cold start to heat the engine up more quickly. This also increases the exhaust note, I'm assuming due to increased back pressure. After the engine is up to temperature, the valve opens again, changing the exhaust note due to increased flow through both sides of the exhaust.

Also during the cold start, the engine automatically revs higher in idle, again to bring up the temp quickly

NO_USER_ · 07-24-2017, 07:05 PM

Quote:

Originally Posted by kab999

There is a baffle that's controlled by an actuator in the exhaust, usually on one side. The valve closes on a cold start to heat the engine up more quickly. This also increases the exhaust note, I'm assuming due to increased back pressure. After the engine is up to temperature, the valve opens again, changing the exhaust note due to increased flow through both sides of the exhaust.

Also during the cold start, the engine automatically revs higher in idle, again to bring up the temp quickly

Valves are open during cold start

kab_m2 · 07-24-2017, 07:08 PM

Quote:

Originally Posted by inline6ax

Quote:

Originally Posted by kab999

There is a baffle that's controlled by an actuator in the exhaust, usually on one side. The valve closes on a cold start to heat the engine up more quickly. This also increases the exhaust note, I'm assuming due to increased back pressure. After the engine is up to temperature, the valve opens again, changing the exhaust note due to increased flow through both sides of the exhaust.

Also during the cold start, the engine automatically revs higher in idle, again to bring up the temp quickly

Valves are open during cold start

Are you sure?

Whenever I cold start my m135i, I always get exhaust fog out of one side. Then after a minute both sides open?

NO_USER_ · 07-24-2017, 07:15 PM

Quote:

Originally Posted by kab999

Are you sure?

Whenever I cold start my m135i, I always get exhaust fog out of one side. Then after a minute both sides open?

Yes, I think the valves are open the majority of the time on the M2.

DivideBYZero · 07-31-2017, 11:43 AM

Just happened to do a video of my completely stock car. Something that's quite rare on YT.

It's interesting how great it sounds, but sound deadening kills most of it off for the driver.

Tag · 07-31-2017, 12:09 PM

Quote:

Originally Posted by DivideBYZero

Just happened to do a video of my completely stock car. Something that's quite rare on YT.

It's interesting how great it sounds, but sound deadening kills most of it off for the driver.

What exhaust tips do you have? From the cameras angle they appear to be slanted and look black. Exhaust sounds great outside the car!

DivideBYZero · 07-31-2017, 01:00 PM

Quote:

Originally Posted by Tag

What exhaust tips do you have? From the cameras angle they appear to be slanted and look black. Exhaust sounds great outside the car!

They are the M4 Comp Pack tips. Direct fit, order from your dealer.

Car is filthy in the video, but I was;t trying to win a concours...!

Tag · 07-31-2017, 01:24 PM

Quote:

Originally Posted by DivideBYZero

They are the M4 Comp Pack tips. Direct fit, order from your dealer.

Car is filthy in the video, but I was;t trying to win a concours...!

That was my initial guess. They are black chrome right? Have any pics you can share?

cookiesowns · 07-31-2017, 02:03 PM

Cold start has the waste gates full open to bypass the turbo in order to heat up the cats quicker as it runs real rich.

Probably also helps the turbos as the oil is still thick so the bearings don’t spin too much.

That said, if you guys really want a loud startup the new v61.4 ISTEP seems to have the ZCP/GTS startup mode in it sounds meaaaaan!

Fuman · 08-01-2017, 08:39 AM

Quote:

Originally Posted by DivideBYZero

Just happened to do a video of my completely stock car. Something that's quite rare on YT.

It's interesting how great it sounds, but sound deadening kills most of it off for the driver.

I can hear the flaps opening and closing?? Is this in comfort??

DivideBYZero · 08-01-2017, 11:15 AM

Quote:

Originally Posted by Fuman

I can hear the flaps opening and closing?? Is this in comfort??

Nope. Started in Traction, then mid way through it's in Sport+. No comfort allowed in my car.

07-22-2017, 01:31 PM	#1
caman New Member 21 Rep 15 Posts Drives: 2017 LBB M2 6 sp, 2015 WRX STI Join Date: Feb 2014 Location: Atlanta iTrader: (0)	Exhaust @ cold start Apologies in advance to the many who have taken time to post on the various Exhaust threads but I'm looking for relatively basic info. My M2 sounds great on cold startup but something changes around 20-30 seconds after startup. Placing in Sport + mode doesn't seem to make a difference. My question is whether there is a way to keep the cold startup sound 20-30 seconds after startup. I am running a stock exhaust system. Thanks.
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07-22-2017, 01:48 PM	#2
mrcheezle19 Lieutenant 375 Rep 507 Posts Drives: 21 M2C 6MT Join Date: Nov 2013 Location: lake elsinore iTrader: (0)	No, that is the engine cold starting and as the idle dies down the sound goes away. I guess you could unlock the ECU and have the idle rpm changed and fueling, but realistically just get an exhaust or downpipe. I'll sell you my GThaus exhaust. It's nasty all the time lol. __________________ Present: 21 M2C 6MT/Ford something Past: M2 Mineral Grey 6MT Past: BMW e30 m52 turbo 628whp/558wtq
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07-22-2017, 01:54 PM	#4
caman New Member 21 Rep 15 Posts Drives: 2017 LBB M2 6 sp, 2015 WRX STI Join Date: Feb 2014 Location: Atlanta iTrader: (0)	Understand but the change I'm hearing is a not gradual change but a distinct step change like a valve is opening or closing - about 20-30 seconds after a cold start.
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07-22-2017, 05:33 PM	#6
ZPrime I INDIC8 612 Rep 1,286 Posts Drives: 2018 LBB M2, 6MT Join Date: Dec 2016 Location: Cleveland, OH iTrader: (0) Garage List 2018 BMW M2 [9.50]	Secondary air injection. it's for emissions. heats the cat quicker. __________________ 2004 Matrix XRS 6MT => 2008 VW R32 DSG => 2012 Audi TTRS 6MT => 2018 BMW ///M2 6MT I'm an IT guy by trade and tech nerd by choice. I like HPDEs, parts of US Hwy 129, NC 28, and the Cherohala Skyway. I'm also a fan of aural pleasure.
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07-22-2017, 07:18 PM	#7
NO_USER_ Captain 538 Rep 752 Posts Drives: . Join Date: Jan 2017 Location: . iTrader: (2)	I'm selling my Remus Exhaust, it'll give you a nice start up sound! Brand new tips, and only about 35 miles on the exhaust.
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07-22-2017, 08:01 PM	#8
DoggieHowser First Lieutenant 211 Rep 360 Posts Drives: F87 Pure F20 125i MSport 2017 Join Date: Apr 2017 Location: Australia iTrader: (0)	The missus is complaining that when the M2 starts up in the garage, which shares a wall with the kitchen where we hang all our cooking utensils, everything is clanging and vibrating. It's going to be mad as hell when I get the M Performance exhaust installed
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07-24-2017, 04:29 PM	#10
BAN_M2C Brigadier General 4185 Rep 3,077 Posts Drives: 991.2 Porsche GT3, BMW E46 M3 Join Date: Jul 2016 Location: Sunshine State iTrader: (5) Garage List 1987 BMW 325is [10.00] 2004 BMW X3 [6.50] 2018 Porsche 911 GT3 [10.00] 1974 BMW 2002tii [10.00] 2004 BMW M3 [10.00]	Like this? https://instagram.com/p/BW6KybflOeh/ __________________ Follow me on IG Garage: 2018 991.2 GT3\|2013 135i\|2004 M3\|2004 X3\|1987 325is\|1987 325i\|1974 2002tii
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07-31-2017, 11:43 AM	#16
DivideBYZero Never underestimate the Home-Bowl 484 Rep 821 Posts Drives: F87 M2<E92 M3<E46 M3 Join Date: Jul 2011 Location: UK iTrader: (0) Garage List 2017 BMW M2 [0.00] 2016 BMW M235i [0.00] 2012 BMW 120d M Spo ... [0.00] 2010 BMW M3 - SOLD [10.00] 2002 BMW Z3 2.2i Sport [0.00] 2001 BMW M3 - SOLD [9.00]	Just happened to do a video of my completely stock car. Something that's quite rare on YT. It's interesting how great it sounds, but sound deadening kills most of it off for the driver. __________________ 2017 F87 M2, MG, M-DCT 2002 E36/7 Z3 2.2 Sport 5MT 2016 F22 M235i Coupe, MW, ZF8
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07-31-2017, 02:03 PM	#20
cookiesowns ;) 587 Rep 898 Posts Drives: X5 45e, 535i N54, X3 N55 Join Date: Jan 2011 Location: West iTrader: (0)	Cold start has the waste gates full open to bypass the turbo in order to heat up the cats quicker as it runs real rich. Probably also helps the turbos as the oil is still thick so the bearings don’t spin too much. That said, if you guys really want a loud startup the new v61.4 ISTEP seems to have the ZCP/GTS startup mode in it sounds meaaaaan!
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