Exhaust flow not even?

Miller335 · 01-23-2015, 09:20 AM

Took a cold start vid for the hell of it and noticed that more exhaust was coming out the driver tailpipe than the passanger side.

How is this even possible?
I have exhaust flap unplugged and I thought coupes had an X pipe connecting both sides.

(Hit play on the vid, I dont know why the preview says image not available)

3000GT MR · 01-23-2015, 10:44 AM

If I'm not mistaken, I believe one of the SW revisions BMW came out with closed one wastegate and opened the other to address the rattle and responsiveness of the throttle. It may just be a velocity thing caused by that and not actual volume.

samsamwu · 01-23-2015, 10:53 AM

actually there is a servo in the pipes that keep one tailpipe closed when cold, this purpose is for warming up faster

Jeff@TopGearSolutions · 01-23-2015, 10:54 AM

I'm pretty sure this is normal. My car did the same thing even with golf tee mod, especially on cold start. The exhaust isn't perfectly even to begin with either.

Miller335 · 01-23-2015, 01:46 PM

Quote:

Originally Posted by samsamwu

actually there is a servo in the pipes that keep one tailpipe closed when cold, this purpose is for warming up faster

Not sure if you saw my OP but that's unplugged.
Also, the side that has more velocity is the side with the flap.

Miller335 · 01-23-2015, 01:47 PM

Quote:

Originally Posted by Jeff@TopGearSolutions

I'm pretty sure this is normal. My car did the same thing even with golf tee mod, especially on cold start. The exhaust isn't perfectly even to begin with either.

OK thanks for heads up.

1chanc3 · 01-23-2015, 01:49 PM

Quote:

Originally Posted by samsamwu

actually there is a servo in the pipes that keep one tailpipe closed when cold, this purpose is for warming up faster

The flapper was unplugged. That's why exhaust is coming out of both tail pipes. If it was still intact, exhaust would only come out of the passenger pipe on warm up.

01-23-2015, 09:20 AM	#1
Miller335 Colonel 291 Rep 2,189 Posts Drives: 2007 E92 Join Date: Oct 2013 Location: Portland, OR iTrader: (0)	Exhaust flow not even? Took a cold start vid for the hell of it and noticed that more exhaust was coming out the driver tailpipe than the passanger side. How is this even possible? I have exhaust flap unplugged and I thought coupes had an X pipe connecting both sides. (Hit play on the vid, I dont know why the preview says image not available) __________________ 2007 E92 335 6MT w/335is clutch FBO MHD E60 Wedge map 49k miles Last edited by Miller335; 01-23-2015 at 09:30 AM..
	Appreciate 0 Tweet Quote

01-23-2015, 10:44 AM	#2
3000GT MR Major 265 Rep 1,392 Posts Drives: 09 335i/3000gt vr4 Join Date: Jun 2012 Location: Sav GA iTrader: (6)	If I'm not mistaken, I believe one of the SW revisions BMW came out with closed one wastegate and opened the other to address the rattle and responsiveness of the throttle. It may just be a velocity thing caused by that and not actual volume. __________________ Have a single turbo and/or tired of burning up O2 sensors? Ask me about the new ADV O2 sensor retro kits! 335i 2010 e92 M-sport Mods: VM Top mount 6466, Aquamist HSF4 w/custom direct port. VRSF IC + Exhaust 335i 2009 e90 665RWHP VFF900 ST RIP .
	Appreciate 0 Quote

01-23-2015, 10:53 AM	#3
samsamwu Private First Class 11 Rep 134 Posts Drives: bmw Join Date: Sep 2007 Location: socal iTrader: (0)	actually there is a servo in the pipes that keep one tailpipe closed when cold, this purpose is for warming up faster
	Appreciate 0 Quote

01-23-2015, 10:54 AM	#4
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	I'm pretty sure this is normal. My car did the same thing even with golf tee mod, especially on cold start. The exhaust isn't perfectly even to begin with either.
	Appreciate 0 Quote