N54 Backfiring? - Page 2 - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)

Drace1 · 02-04-2013, 04:32 PM

Quote:

Originally Posted by SpeedballTrix

is awesome.

/thread

Im with Speedball, most people look for this sound! Sit back relax and enjoy letting off the throttle and hearing that backfire noise.

I'm actually looking forward to having some more backfire in the future. Kind of jealous of EinserM's sound, I got the craziest sound clip from it yesterday and haven't stopped watching/listening to it.

Freon · 02-04-2013, 05:11 PM

I tend to think this is caused not necessarily "lean" or "rich" but both in quick succession due to lag in sensors. Your MAP or MAF sensor isn't instantaneous, so when you suddenly go from 100% to 0% throttle there can be spikes. I would tend to think you're rich at high throttle, and a sudden throttle reduction to 0% can cause the injectors to turn off, pump some of the leftover air in the intake manifold (pure air, ~21% oxygen) into the exhaust where there is still some rich mixture, and the super hot turbine wheel or other hotspot in the exhaust will trigger combustion.

I wouldn't sweat it. Your car always did this, you just didn't really notice due to the factory catalysts, mufflers, and resonators.

NickyC · 02-05-2013, 12:48 AM

Popping/gurgling on my car is pretty wild under deceleration. I have a straight through exhaust, Cobb Stage 2+ car and I adore the sound. I've had quite a few excited teenagers or whatever pull up to me after a spirited launch and tell me the car spit pretty nice flames out the back. I've never seen it in person however, so I'll have to take their word for it.

SteveAZ · 02-05-2013, 01:56 AM

Negative....you do not go rich during shifts....

Cozy · 02-05-2013, 04:24 AM

Rip out the mid-cats, resonator and install a new axle-back and the gurgling and pops get pretty insane. I out-gurgled a McLaren 12C on the weekend but sadly in all other departments he would have destroyed me

.

NickyC, I cannot imagine how wild your car sounds

pkim1079 · 02-10-2013, 05:31 AM

This is an old post but gurgling is nothing. And my stock n55 had a huge backfire tonight going hard up "the snake". When i got to the area where ppl park and hang out, they were going shits and giggles nuts over it. I was surprised and thought i hit a branch on the undercarriage at first but apparently it echoed all the way up to the spectators. Nice.

jose325i · 04-07-2013, 09:05 PM

Once, I accelerated WOT and shifted from 1-2 in Manual mode (step tranny) around 3-3.5k...Heard a LOUD "bang" from the exhaust, and got a service engine soon light.

I think the car turned off 2-3 cylinders afterwards. When I tried to accelerate, the RPM gauge would just wobble up and down, almost no power. After driving relaxed for a minute, the light went away and the car went back to normal. Anyone had this happen? I'm 100% stock...

335chi · 04-19-2013, 06:39 PM

Quote:

Originally Posted by jose325i

Once, I accelerated WOT and shifted from 1-2 in Manual mode (step tranny) around 3-3.5k...Heard a LOUD "bang" from the exhaust, and got a service engine soon light.

I think the car turned off 2-3 cylinders afterwards. When I tried to accelerate, the RPM gauge would just wobble up and down, almost no power. After driving relaxed for a minute, the light went away and the car went back to normal. Anyone had this happen? I'm 100% stock...

Sounds like misfire which is common N54 code - do you have access to an OBD scanner to check for stored codes?

themellly · 04-19-2013, 06:48 PM

Quote:

Originally Posted by RealityDesign

To get REAL backfire (flames out the exhaust tips), you'd need to be completely catless.

Very true. Such a huge difference. If I get it in the right moment sometimes its like gunshots. If your loving the sound now, remove all the cats and then you'll be really excited!

02-04-2013, 05:11 PM	#24
Freon Lieutenant Drives: 2009 135i Join Date: Nov 2007 Location: Indianapolis Posts: 401 iTrader: (2)	I tend to think this is caused not necessarily "lean" or "rich" but both in quick succession due to lag in sensors. Your MAP or MAF sensor isn't instantaneous, so when you suddenly go from 100% to 0% throttle there can be spikes. I would tend to think you're rich at high throttle, and a sudden throttle reduction to 0% can cause the injectors to turn off, pump some of the leftover air in the intake manifold (pure air, ~21% oxygen) into the exhaust where there is still some rich mixture, and the super hot turbine wheel or other hotspot in the exhaust will trigger combustion. I wouldn't sweat it. Your car always did this, you just didn't really notice due to the factory catalysts, mufflers, and resonators. __________________ 2009 BMW 135i, 6 MT, M Sport, DIY DCI, Cobb AP, Apex 18x8.5+9.5, 235/265 Starspecs

02-05-2013, 01:56 AM	#26
SteveAZ First Lieutenant Drives: 135i Cab Join Date: Jul 2012 Location: Phoenix, AZ Posts: 346 iTrader: (2)	Negative....you do not go rich during shifts.... __________________ 2008 AW E88 Auto Current--AA FMIC--BMS BEF (w/Cobb), G5 ISO, SLD, CPS, DCIs, & OCC--M3 FSB & FCAs--ER OC--Walbro IFP--RB PCV--Whiteline RSFBs--ER SS brakelines--Stoptech slotted rotors w/Ferodo pads--Apex Arc 8s wrapped in Michelin PSS Future upgrades: Wavetrac LSD TBD: coilovers

02-05-2013, 04:24 AM	#27
Cozy Major Drives: E82 135i Join Date: Mar 2011 Location: Surrey, England Posts: 1,216 iTrader: (0)	Rip out the mid-cats, resonator and install a new axle-back and the gurgling and pops get pretty insane. I out-gurgled a McLaren 12C on the weekend but sadly in all other departments he would have destroyed me . NickyC, I cannot imagine how wild your car sounds __________________ BMW 135i N54 \| Black Sapphire \| M-Sport \| BMS 10mm Spacers (Rear) \| Eibach 5mm Spacers (Front) \| Gunmetal 261M 18" Wheels \| Vredestein Ultrac Sessanta 225/255 \| LCI Tails \| COBB AP Stage 1+ \| Matt Black Grilles \| BMW PE + Resonator Delete \| N55 Midpipe \| Rieger Tuning Matt Black Diffuser \| ETS FMIC

02-10-2013, 05:31 AM	#28
pkim1079 Lieutenant Colonel Drives: e90 ///M3 ZCP + e82 135i DCT Join Date: Dec 2009 Location: lost angeles Posts: 1,515 iTrader: (0)	This is an old post but gurgling is nothing. And my stock n55 had a huge backfire tonight going hard up "the snake". When i got to the area where ppl park and hang out, they were going shits and giggles nuts over it. I was surprised and thought i hit a branch on the undercarriage at first but apparently it echoed all the way up to the spectators. Nice. __________________ 1,2,3,4,5,6,7,8.3 shift! (repeat!!) who needs software when you can tune the DRIVER?

04-07-2013, 09:05 PM	#29
jose325i New Member Drives: 2008 135i Join Date: Sep 2011 Location: Houston Posts: 6 iTrader: (0)	Once, I accelerated WOT and shifted from 1-2 in Manual mode (step tranny) around 3-3.5k...Heard a LOUD "bang" from the exhaust, and got a service engine soon light. I think the car turned off 2-3 cylinders afterwards. When I tried to accelerate, the RPM gauge would just wobble up and down, almost no power. After driving relaxed for a minute, the light went away and the car went back to normal. Anyone had this happen? I'm 100% stock... __________________

02-05-2013, 12:48 AM	#25
NickyC Lieutenant Drives: Something German. Join Date: Nov 2010 Location: Somewhere I don't want to be Posts: 421 iTrader: (6)	Popping/gurgling on my car is pretty wild under deceleration. I have a straight through exhaust, Cobb Stage 2+ car and I adore the sound. I've had quite a few excited teenagers or whatever pull up to me after a spirited launch and tell me the car spit pretty nice flames out the back. I've never seen it in person however, so I'll have to take their word for it.

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