Back pressure

Giggs11 · 11-15-2017, 02:16 AM

Hi all I hear you loose back pressure ( gargle ) of Msport and car gets slower 0-60 if you zip tie exhaust flap open. Is it true?

Walt White Coupe · 11-15-2017, 07:27 AM

I think it's a bunch of baloney.

The exhaust 'flappers' open at higher RPMs and full power to reduce back pressure and increase horsepower. My Corvette has a similar system called a 'dual mode' exhaust and it's an option. The C6 system opened at 3500 RPM and the engine was rated at 5 more HP than the car without the 'dual mode' system. My C7 has the same system but it's controllable depending on what driving mode you are in. In Economy or Tour it acts like the C6 and opens up at 3500 RPM, in Sport or Track mode it's open all the time. And with the optional 'Dual Mode' the engine again is rated at 460 HP vs. the engine without is rated at 455 HP.

Giggs11 · 11-16-2017, 03:08 AM

Hi ty this is something I read on one of the BMW forums some people did agree some didn't so I'm just trying to hear more opinions

11-15-2017, 02:16 AM	#1
Giggs11 Private First Class 49 Rep 198 Posts Drives: 13' f13 650i xdrive,M package Join Date: May 2017 Location: Florida iTrader: (0)	Back pressure Hi all I hear you loose back pressure ( gargle ) of Msport and car gets slower 0-60 if you zip tie exhaust flap open. Is it true?
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11-15-2017, 07:27 AM	#2
Walt White Coupe Captain 221 Rep 738 Posts Drives: 2013 650ix Coupe, 23 C8 Vette Join Date: Mar 2011 Location: Phila, PA iTrader: (0)	I think it's a bunch of baloney. The exhaust 'flappers' open at higher RPMs and full power to reduce back pressure and increase horsepower. My Corvette has a similar system called a 'dual mode' exhaust and it's an option. The C6 system opened at 3500 RPM and the engine was rated at 5 more HP than the car without the 'dual mode' system. My C7 has the same system but it's controllable depending on what driving mode you are in. In Economy or Tour it acts like the C6 and opens up at 3500 RPM, in Sport or Track mode it's open all the time. And with the optional 'Dual Mode' the engine again is rated at 460 HP vs. the engine without is rated at 455 HP.
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11-16-2017, 03:08 AM	#3
Giggs11 Private First Class 49 Rep 198 Posts Drives: 13' f13 650i xdrive,M package Join Date: May 2017 Location: Florida iTrader: (0)	Hi ty this is something I read on one of the BMW forums some people did agree some didn't so I'm just trying to hear more opinions
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