Has anyone coded out their cold start, is it quieter?

Ginger_Extract · 02-11-2017, 01:30 PM

After installing the catess downpipes my car is INSANELY loud on cold starts. After that it's fine. However it is impossible to quietly leave my neighborhood as is. This morning someone called the cops after I left and my very upset room mate had to deal with it.
Has anyone coded out their cold start and did it make an appreciable difference in volume reduction? It's incredible that it can be so goddamn loud on cold starts and totally fine the rest of the time.

ShocknAwe · 02-11-2017, 01:43 PM

What are you using for tune man? MHD has cold start fix for both standalone and BMS backends

Ginger_Extract · 02-11-2017, 02:43 PM

Quote:

Originally Posted by ShocknAwe

What are you using for tune man? MHD has cold start fix for both standalone and BMS backends

JB4 w/ Back End Flash. Sounds like I'll have to hop on the MHD train. Have you tried it? Is the difference appreciable?

ShocknAwe · 02-11-2017, 04:05 PM

Quote:

Originally Posted by Ginger_Extract

JB4 w/ Back End Flash. Sounds like I'll have to hop on the MHD train. Have you tried it? Is the difference appreciable?

I haven't tried any of the standalones, currently using MHD to flash the backends.

dsocold · 02-11-2017, 05:41 PM

i have mhd, and i selected the quieter cold start option and i can say that it definetly does get rid of the loud startups with my n54 its pretty much almost like starting a warm car.

titium · 02-11-2017, 05:57 PM

yep mhd option works as advertised. no raised idle, no open wastegates = much quieter cold starts

bNks334 · 02-12-2017, 05:31 PM

Before I got cold start delete (MHD) I used to hold the revs at ~1500 rpms upon startup. That keeps the engine quite! Not as effective as the actual cold start delete, but it will keep your neighbors from calling the cops on you again until you get the situation properly sorted.

drunkenup · 02-12-2017, 08:28 PM

The initial fire up is extremely loud, still. I think there are several layers of 'cold start' in the computer and the car still idles at ~850 before falling to 600, not nearly as bad as stock but my exhaust setup is still very loud. Maybe you need to fabricate a silencer for mornings

weeeee · 02-12-2017, 08:34 PM

It's loud for about 0.5 seconds, idle drops, and it's much quieter. Even with golf t mod.

drunkenup · 02-12-2017, 08:47 PM

Had this on my phone, this is what mine sounds like

Cmoney135i · 02-15-2017, 01:28 PM

Quote:

Originally Posted by bNks334

Before I got cold start delete (MHD) I used to hold the revs at ~1500 rpms upon startup. That keeps the engine quite! Not as effective as the actual cold start delete, but it will keep your neighbors from calling the cops on you again until you get the situation properly sorted.

uhhh what? the oil isn't even circulated and your revving the engine?

Rob_BMW_PNW · 02-15-2017, 02:56 PM

Quote:

Originally Posted by Cmoney135i

uhhh what? the oil isn't even circulated and your revving the engine?

I think what he meant was after the car has started, he would hold at 1500

katsooba · 02-15-2017, 02:56 PM

jb4+mhd here on a 3.25" custom exhaust.
cold start is coded out and even after a night of parking the car starts as if i just turned the motor off
QUIET

drwillb · 02-15-2017, 06:47 PM

What is the reason/function for the loud cold start?

From what I read on a post somewhere I think the sound comes from the wastegates being held open. I imagine that must be to protect the turbo from spooling up before there is adequate oil pressure and flow, especially on a cold day. Is there any danger, then, to not allow for this safety period by closing the waste gates?

titium · 02-15-2017, 07:04 PM

Quote:

Originally Posted by drwillb

What is the reason/function for the loud cold start?

From what I read on a post somewhere I think the sound comes from the wastegates being held open. I imagine that must be to protect the turbo from spooling up before there is adequate oil pressure and flow, especially on a cold day. Is there any danger, then, to not allow for this safety period by closing the waste gates?

nope its to warm up the cats quicker. car also does some vanos stuff, dumps extra fuel and runs different ignition timing to speed up the heating process.

5 seconds of raised idle would be nice to help with the slight roughtness when it's cold.

bNks334 · 02-16-2017, 09:20 AM

Quote:

Originally Posted by Cmoney135i

uhhh what? the oil isn't even circulated and your revving the engine?

Cold start revs the engine high immediately upon startup... this builds instant oil pressure... I am not talking about pinning redline. There is no significant extra loading on the engine at 1500 rpms... it's the same load if not lesss. light throttle input takes the car out of the cold start loop... Oil pressure buolds the instant the engine turns over.

The car stays loud for a long time even after cranking because its dumping fuel and the secondary air pump is running. If you have a catless downpipe the air pump isn't needed anymore anyway so you're not gaining anything by letting the car go through its cold start cycle. All the cold start cycle does is warm the cat up for emissions purposes.

drwillb · 02-16-2017, 11:42 AM

Good info.

Thank you.

deesea · 02-19-2017, 10:49 AM

I coded mine off via MHD for a brief period of time. Noticed that when I cold start the car, it would shake at idle a lot. Anyone else have this issue? Maybe I have an injector or coil pack on its way out. The problem went away after I coded it back in. Car drives normally otherwise.

bNks334 · 03-03-2017, 09:53 AM

Quote:

Originally Posted by deesea

I coded mine off via MHD for a brief period of time. Noticed that when I cold start the car, it would shake at idle a lot. Anyone else have this issue? Maybe I have an injector or coil pack on its way out. The problem went away after I coded it back in. Car drives normally otherwise.

No, I think this is just tuning that could use a bit of tweaking to keep th eengine happy on cold starts...

02-11-2017, 01:30 PM	#1
Ginger_Extract California-bound 385 Rep 1,480 Posts Drives: BMW 135i Join Date: Jan 2013 Location: Los Angeles, CA iTrader: (3)	Has anyone coded out their cold start, is it quieter? After installing the catess downpipes my car is INSANELY loud on cold starts. After that it's fine. However it is impossible to quietly leave my neighborhood as is. This morning someone called the cops after I left and my very upset room mate had to deal with it. Has anyone coded out their cold start and did it make an appreciable difference in volume reduction? It's incredible that it can be so goddamn loud on cold starts and totally fine the rest of the time. __________________ Streets of Willow: 1:27.7 CW 11/15/15; 1:29.5 CCW 8/15/15 \|\|\|\| Autoclub Speedway ROVAL (CCW): 1.52.6 - 12/2/17 Willow Springs - Big Willow (CW): 1:35.8 - 3/31/18 \|\|\|\| Buttonwillow #13 (CW): 1:59.3 1/27/18 https://www.facebook.com/JakeStumphRacing \|\|\|\| http://www.youtube.com/user/RaceMeMZ3
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02-11-2017, 01:43 PM	#2
ShocknAwe 1Addict 3234 Rep 7,894 Posts Drives: E82 Mutt, M57 Truck Join Date: Jul 2012 Location: Charleston iTrader: (22)	What are you using for tune man? MHD has cold start fix for both standalone and BMS backends __________________ 2010 135i 6MT Jet Black N54/3 FE82 Mutt \| BUILD THREAD \| GARAGE SALE
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02-11-2017, 05:41 PM	#5
dsocold Captain 198 Rep 684 Posts Drives: f06 640i GC. E82 N54 135i Join Date: Apr 2015 Location: new york iTrader: (0)	i have mhd, and i selected the quieter cold start option and i can say that it definetly does get rid of the loud startups with my n54 its pretty much almost like starting a warm car.
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02-11-2017, 05:57 PM	#6
titium Major 327 Rep 960 Posts Drives: 2009 BMW 135i Join Date: Jun 2015 Location: Sydney iTrader: (0)	yep mhd option works as advertised. no raised idle, no open wastegates = much quieter cold starts
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02-12-2017, 05:31 PM	#7
bNks334 Major 427 Rep 957 Posts Drives: '11 135i (N55) Join Date: May 2014 Location: New York iTrader: (1)	Before I got cold start delete (MHD) I used to hold the revs at ~1500 rpms upon startup. That keeps the engine quite! Not as effective as the actual cold start delete, but it will keep your neighbors from calling the cops on you again until you get the situation properly sorted.
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02-12-2017, 08:28 PM	#8
drunkenup Captain 215 Rep 988 Posts Drives: 2009 135i, 2021 F150 Join Date: Sep 2013 Location: NJ iTrader: (1)	The initial fire up is extremely loud, still. I think there are several layers of 'cold start' in the computer and the car still idles at ~850 before falling to 600, not nearly as bad as stock but my exhaust setup is still very loud. Maybe you need to fabricate a silencer for mornings __________________ MHD \| BMS \| VRSF \| APEX \| RECARO \| TC Kline \| BERK \| Turner Motorsport \| Eibach \| BMW Performance
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02-12-2017, 08:34 PM	#9
weeeee Private First Class 40 Rep 133 Posts Drives: 2011 135i Join Date: Mar 2012 Location: 757 iTrader: (1)	It's loud for about 0.5 seconds, idle drops, and it's much quieter. Even with golf t mod.
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02-12-2017, 08:47 PM	#10
drunkenup Captain 215 Rep 988 Posts Drives: 2009 135i, 2021 F150 Join Date: Sep 2013 Location: NJ iTrader: (1)	Had this on my phone, this is what mine sounds like __________________ MHD \| BMS \| VRSF \| APEX \| RECARO \| TC Kline \| BERK \| Turner Motorsport \| Eibach \| BMW Performance
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02-15-2017, 02:56 PM	#13
katsooba First Lieutenant 85 Rep 354 Posts Drives: bmw 135i Join Date: Apr 2012 Location: Israel iTrader: (0)	jb4+mhd here on a 3.25" custom exhaust. cold start is coded out and even after a night of parking the car starts as if i just turned the motor off QUIET __________________ 135i N55 / KW V3 / MHD Flash / Tons of grip mods / CP-E charge pipe / CP-E 7" FMIC
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02-15-2017, 06:47 PM	#14
drwillb BMW Fan 289 Rep 838 Posts Drives: e30 M3, e30 M3, e46 M3 Join Date: Aug 2008 Location: northern NJ iTrader: (4)	What is the reason/function for the loud cold start? From what I read on a post somewhere I think the sound comes from the wastegates being held open. I imagine that must be to protect the turbo from spooling up before there is adequate oil pressure and flow, especially on a cold day. Is there any danger, then, to not allow for this safety period by closing the waste gates?
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02-16-2017, 11:42 AM	#17
drwillb BMW Fan 289 Rep 838 Posts Drives: e30 M3, e30 M3, e46 M3 Join Date: Aug 2008 Location: northern NJ iTrader: (4)	Good info. Thank you. __________________ 2012 135i Mods: air scoops, CP, K&N filter, PS1, ADE FMIC, BMW PE, JB4, 1M front body, full M3 suspension front and rear, M3 brakes front and rear, M3 rear subframe and LSD Owned so far: 88 M3 x 2, 95 325is, 95 M3 x 2, 06 Mini Cooper S, 08 335 xi, 09 Z4 35i, 01 M3, 12 135i
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02-19-2017, 10:49 AM	#18
deesea First Lieutenant 60 Rep 351 Posts Drives: 2009 135i Join Date: Jul 2015 Location: Markham, ON iTrader: (1)	I coded mine off via MHD for a brief period of time. Noticed that when I cold start the car, it would shake at idle a lot. Anyone else have this issue? Maybe I have an injector or coil pack on its way out. The problem went away after I coded it back in. Car drives normally otherwise.
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