View Single Post
      03-25-2014, 05:47 PM   #109
eyim1988
Lieutenant Colonel
eyim1988's Avatar
98
Rep
1,647
Posts

Drives: 2022 BMW M4
Join Date: Feb 2011
Location: Los Angeles, CA

iTrader: (5)

Garage List
2022 M4  [0.00]
Quote:
Originally Posted by dd1981
Quote:
Originally Posted by twelve535i
Quote:
Originally Posted by dd1981 View Post
Because the Helmholtz chamber is still in tact.
It's louder but not to the point where it will emit unbearable drone.
What confused me at first was the fact that the tubing in chamber 2 has no holes, so I didn't see how that could drown out any noise.
Now that I look at the picture again, it appears that there is an additional pipe the runs from chamber 1 into 2 that you have no touched. Is that correct?
Yes that is 100% correct. There is a smaller tube leading into the Helmholtz chamber that still slows some of the sound to drown out. This is naturally designed by BMW to severely reduce drone.

Someone in an earlier post mentioned they were planning on plugging this hole as well. I advise against this because essentially what you will just end up with is straight pipes. No sound can escape into the Helmholtz chamber hence it will drone and defeating the purpose I set out for.

At this point if he's gonna plug up that hole as well you may as well cut the muffler off and just straight pipe it.
Thats why i only spot welded half the holes. Ill do a better video soon
__________________
Current: 2021 X3MC
Past: 2013 bmw 335i, 2011 bmw 335i coupe, 2016 bmw m3
Appreciate 0