[D CHOI]

Occasionally if I don't want to disturb neighborhoods (late night hours/early mornings) I would start the car in 1st gear and immediately apply throttle to get the car moving to tone down the exhaust note significantly. I'm wondering if this is detrimental to the engine? I know the book says to drive off immediately after starting the car but I assume that's after a second or 2 naturally. Usually I let it sit for less than a minute on average because that Cold Start from the M2 never gets old.

[No Boost]

Cold start, especially with a DP, can be brutally loud. I'll start the car and immediately drive off. From what I gather, it's not detrimental to the engine or drivetrain. Cold start is in place to heat the catalytic converter quickly in order to work efficiently. Folks have had it coded out, something to consider.

[nomade30]

Stage IV is correct cold start is only for heating up the catalyst. The only way to disable it would be to get a custom tune that codes it out.

[stefan]

Code out or Tune out?

If there are codes I'd like to know what they are.

[alscks0414]

Nope it wont hurt the engine or any fluided drivetrain unless (of course) you WOT before oil is warm enough. Little gas after start to get her to calm down is just fine.

I do the exact same thing... Haha I have MPE + Fabspeed Sport Cat DP (+ TrueNorth Winter Climate) makes her angry as hell at cold start...

My day starts at 7am driving to work and usually all my neighbours are in sleep. I usually give it a little gas and clutch it to move about few inches to calm her down in comfort. Drive-off for 2 block to see the wider main road, put her to Sport+ double tab of my BT to open MPE and smile

[Artemis]

FWIW:

Originally Posted by Artemis

The loudest bass sound on the M2 during cold start lasts close to 40 seconds since firing up the engine. Subsequently the deep bass sound dies down and the normal bass sound remains while idling.

What happens AFAIK: the engine management arranges to quickly heat up the catalytic convertors through 'open loop' fueling (fueling control loop: fuel/air-fuel ratio feedback loop between the injector pulse and oxygen sensors). On cold start, some open loop algorithm pulses the injectors until the time that oxygen sensors are sufficiently warmed up to properly do their job. Oxygen sensors feature heater wires to help shorten this time and maintain operating temperature. Hence, the open loop fueling only happens during a brief time window after firing up the engine and won't be triggered that way if the engine was already warmed up to operating temperature (you'll notice that there won't be that hallmark cold start deep bass sound if you restart the engine briefly after a drive). Reason for all this: emissions requirements and getting the cold engine a little quicker up to temp.

With a manual gearbox, the loudness of an M2 cold start (with or without MPE) or 1M (with or without Akrapovič exhaust) can definitely be toned down by using the clutch and accelerator pedals in close harmony. Fire up the engine (if you got MPE: don't open the butterfly valve) and immediately climb a little higher in the revs (thus higher than the usual 1200-900rpm engine idle yo-yo cold start start-up sequence) with the accelerator pedal, whilst partially depressing the clutch pedal. Just a matter of subtle interaction between the left and right feet to slowly move forward/backward out of your parking space whilst gently subduing the deep bass sound. You'll notice that by doing so, you'll reduce that deep bass sound loudness. And as this pedal interaction only takes place at very slow speed and for a very brief period of time (just enough to move the car from its parking spot), it's best to operate when in a location where the deep bass sound could eventually bother other people nearby (especially from dusk till dawn). A lesser known fringe benefit of a 6MT compared to an M-DCT.

Technical explanation (general): "Internal combustion engine cold-start efficiency: A review of the problem, causes and potential solutions":
http://www.sciencedirect.com/science...96890414001939

[bmwizgoat]

Is letting the car sit for 5-10 minutes bad for it ? I tend to do this when it's -25 outside and I park on the street.

[D CHOI]

Originally Posted by bmwizgoat

Is letting the car sit for 5-10 minutes bad for it ? I tend to do this when it's -25 outside and I park on the street.

[Archie Bunker]

You guys are a lot nicer than me. If my car is making legally acceptable noises, I feel no remorse for my neighbors. Now, my dogs barking occasionally after 10pm makes me angry and embarrassed until I shut them up.

[No Boost]

Originally Posted by Archie Bunker

You guys are a lot nicer than me. If my car is making legally acceptable noises, I feel no remorse for my neighbors. Now, my dogs barking occasionally after 10pm makes me angry and embarrassed until I shut them up.

You live in Texas, correct? There's a difference between 60° cold start and 10° cold start. It's substantially louder in very cold temps.

[alscks0414]

Originally Posted by bmwizgoat

Is letting the car sit for 5-10 minutes bad for it ? I tend to do this when it's -25 outside and I park on the street.

There is no need of warming up the engine at idle like old time. Just drive off slowly after start and try to keep it below 3k rpm until oil temp warmed up

[Archie Bunker]

Originally Posted by Stage IV

You live in Texas, correct? There's a difference between 60° cold start and 10° cold start. It's substantially louder in very cold temps.

You do make a good point. Further to your point, my car is always started in the warm garage. Maybe I should leave it outside over the cold(ish) weekend, start it one morning, and see how many HOA letters I get.

[No Boost]

Originally Posted by Archie Bunker

You do make a good point. Further to your point, my car is always started in the warm garage. Maybe I should leave it outside over the cold(ish) weekend, start it one morning, and see how many HOA letters I get.

Funny you mention HOA. The manager of my complex told me he got a complaint from a crotchety old man. It was probably the Harley that, per the rules, isn't allowed in the complex. The thing is, it's unenforceable, just like a loud car. I'm eagerly awaiting a confrontation from said old man. I may just may feel the need to perform a redline clutch dump for his audible pleasure.

[Potatohead-M2]

Originally Posted by Stage IV

Funny you mention HOA. The manager of my complex told me he got a complaint from a crotchety old man. It was probably the Harley that, per the rules, isn't allowed in the complex. The thing is, it's unenforceable, just like a loud car. I'm eagerly awaiting a confrontation from said old man. I may just may feel the need to perform a redline clutch dump for his audible pleasure.

Give him one of these lol

[F87_LCI]

I swear I am getting deja-vu reading this thread...

Anyway, I find that a double tap of the MPE button on cold start actually makes the car quieter on idle - still sounds like a truck according to my wife, lol. Getting it out of the garage and down the street might be another issue...

[pissclams]

if it’s too loud, you’re too old

[stefan]

Originally Posted by bmwizgoat

Is letting the car sit for 5-10 minutes bad for it ? I tend to do this when it's -25 outside and I park on the street.

No. Give it 30 sec and off you go. Page 180 in your manual. However, If you're parking in -25 and letting it sit, you will want to seriously make some changes. I suggest dropping the cold viscosity of the oil, maybe to 0w40. I'd also consider a block heater, though I have no idea if they are available for the N55.

[lax01]

Originally Posted by pissclams

if it’s too loud, you’re too old

Agreed

[matty_f]

I would love the option of a quieter cold start exhaust. I try not to shit where I eat. I like my neighbors, and I know they hear when I leave to hit the canyons before the crack of dawn.

Maybe if I lived in an apartment where noise is just a fact of life, I’d say “if it’s too loud, you’re too old.”

[Corinne]

Originally Posted by Archie Bunker

You guys are a lot nicer than me. If my car is making legally acceptable noises, I feel no remorse for my neighbors. Now, my dogs barking occasionally after 10pm makes me angry and embarrassed until I shut them up.

Hear hear. My neighbors are utterly horrible and their dog barks at me non stop whenever I’m in my garden. It can go on for hours. My response is an early morning cold start in sub zero temperatures with a Fabspeed, the car parked outside under my front porch with a clear line of sight to the neighbors. I never move until those orchestral 40 seconds are over

[Aronis]

The homes are far enough apart here that I don't think either of my loud cars bothers any of my neighbors. We have to dogs too. The boy likes to bark a bit. So far no complaints.

Now the guy who flies his acrobatic plane over our neighborhood, He is hated!

Mike

[No one]

Originally Posted by pissclams

if it’s too loud, you’re too old

If it's your best idea you're too young.

Originally Posted by Corinne

My neighbors are utterly horrible and their dog barks at me non stop whenever I’m in my garden. It can go on for hours. My response is an early morning cold start in sub zero temperatures with a Fabspeed, the car parked outside under my front porch with a clear line of sight to the neighbors. I never move until those orchestral 40 seconds are over

And so you do your best to feed it with a reason. Does your dog (Megabyte) bark back for you or is she just too clever to get involved?