Anybody disable the flap on the muffler?

NoMods · 07-04-2006, 12:53 PM

What advantages is there to an open or closed flap on the muffler? I think it's on a 330 only and it looks like a passive system???

Artz 330 · 07-04-2006, 02:06 PM

Quote:

Originally Posted by armoredsaint

What advantages is there to an open or closed flap on the muffler? I think it's on a 330 only and it looks like a passive system???

It closes in the lower RPM range (Off a light) to increase back pressure which increases TQ. Disabling this will barely do anything but you will notice a slight decrease in TQ in the low speed (0 up to about 50-60mph) and low RPM range.

obLu · 07-05-2006, 04:52 PM

I'd thought it was for EU noise regulations. At least that was the theory back in the e46 days when it first appeared. Check over at e46fanatics, used to be a ton of posts on how people went about sealing off the solenoid line to disable it. Not sure if anybody bothers with it anymore though.

HRC · 07-05-2006, 10:18 PM

Quote:

Originally Posted by Artz 330

It closes in the lower RPM range (Off a light) to increase back pressure which increases TQ. Disabling this will barely do anything but you will notice a slight decrease in TQ in the low speed (0 up to about 50-60mph) and low RPM range.

It has to do with sound, not HP or torque.

Danny

07-04-2006, 12:53 PM	#1
NoMods Colonel 1133 Rep 2,334 Posts Drives: 2022 M5 Join Date: May 2006 Location: USA iTrader: (10) Garage List 2022 M5 [10.00]	Anybody disable the flap on the muffler? What advantages is there to an open or closed flap on the muffler? I think it's on a 330 only and it looks like a passive system???
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07-05-2006, 04:52 PM	#3
obLu Major 50 Rep 1,159 Posts Drives: 330i 6MT ZSP Join Date: Jun 2005 Location: Kirkland, WA, USA iTrader: (1)	I'd thought it was for EU noise regulations. At least that was the theory back in the e46 days when it first appeared. Check over at e46fanatics, used to be a ton of posts on how people went about sealing off the solenoid line to disable it. Not sure if anybody bothers with it anymore though.
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