Thoughts on this custom downpipe muffler combo

overlook637 · 11-08-2018, 05:33 PM

My buddy who lives in El Salvador, doesn't have to worry about EPA.

The downpipes cat was opened up and the metal catalytic was removed. Hoping to change the sound, the inside of the chamber was fabricated into a very race type muffler.

One downpipe muffler has a half of a 2" pipe placed in the center. Should be plenty of air flow around this. Sound waves don't have a direct path thru.
Second downpipe muffler has two 1.75" pipes cut in half and staggered. This also should have plenty of air flow and prevent direct sound waves.

Thoughts, flames, thumbs up or down.

Cost was 100$ for the fabrication and about 40$ in supplies to cut the chamber open and removed the inside. Factory bends, connections, expansion section. Hopefully a positive or improved sound. Or at the very least a less lawnmower sound.

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overlook637 · 11-08-2018, 05:34 PM

overlook637 · 11-08-2018, 05:35 PM

gabriel.psd · 11-08-2018, 05:41 PM

Quote:

Originally Posted by overlook637

My buddy who lives in El Salvador, doesn't have to worry about EPA.

best thread intro, ever.

Brasko · 11-09-2018, 09:26 AM

I think you would get more replies/feedback if you posted some sound clips along with the design.

overlook637 · 11-09-2018, 02:55 PM

Sound clips will be after ceramic coating.

jpsimon · 11-09-2018, 03:06 PM

Definitely post a sound clip once this is done!

mynameisplayer · 11-10-2018, 12:56 AM

Very interested to hear - common trick removing the cat innards on every other tuned car, keen to see what it'll do on the F80.

Dr._Who · 11-11-2018, 11:13 PM

Quote:

Originally Posted by overlook637

My buddy who lives in El Salvador...

Hey,

Please forward to your "buddy".

* https://f80.bimmerpost.com/forums/sh....php?t=1502460

Thanx!

Cheers!

overlook637 · 11-30-2018, 06:42 PM

Ceramic Coating from SwainTech was 165$.

Pictures coming next week. Videos by next weekend.

overlook637 · 12-19-2018, 04:09 PM

Sounds great so far. Before the car had been tuned for all open flaps with resonator swap. The sound quality was ok and the volume was about right. Now it seams like there is less volume inside the car with a much improved sound quality. Zero drone. So far my buddy is happy..

The downpipe with 2 staggered halves were modified with 2 half inch holes drilled out per section. Looked like the 2 full half pipes would cause too much restriction. The extra holes should equal out the gas flow.

Video to be posted at later date.

11-08-2018, 05:33 PM	#1
overlook637 Lieutenant 245 Rep 466 Posts Drives: M4 Join Date: Mar 2018 Location: USA iTrader: (0)	Thoughts on this custom downpipe muffler combo My buddy who lives in El Salvador, doesn't have to worry about EPA. The downpipes cat was opened up and the metal catalytic was removed. Hoping to change the sound, the inside of the chamber was fabricated into a very race type muffler. One downpipe muffler has a half of a 2" pipe placed in the center. Should be plenty of air flow around this. Sound waves don't have a direct path thru. Second downpipe muffler has two 1.75" pipes cut in half and staggered. This also should have plenty of air flow and prevent direct sound waves. Thoughts, flames, thumbs up or down. Cost was 100$ for the fabrication and about 40$ in supplies to cut the chamber open and removed the inside. Factory bends, connections, expansion section. Hopefully a positive or improved sound. Or at the very least a less lawnmower sound. - Last edited by overlook637; 11-08-2018 at 06:05 PM..
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11-08-2018, 05:34 PM	#2
overlook637 Lieutenant 245 Rep 466 Posts Drives: M4 Join Date: Mar 2018 Location: USA iTrader: (0)	<img src="https://image.ibb.co/jAKAFA/IMG-2409.jpg" alt="IMG-2409" border="0">
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11-08-2018, 05:35 PM	#3
overlook637 Lieutenant 245 Rep 466 Posts Drives: M4 Join Date: Mar 2018 Location: USA iTrader: (0)
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11-09-2018, 09:26 AM	#5
Brasko #LSBM3 1420 Rep 1,973 Posts Drives: 2016 BMW M3 Join Date: Feb 2015 Location: Oregon / Florida iTrader: (4) Garage List 1984 BMW R65 [0.00] 2020 Ford F-150 XLT ... [0.00] 2003 Mitsubishi Evo ... [0.00] 2016 M3 Competition ... [10.00]	I think you would get more replies/feedback if you posted some sound clips along with the design. __________________ /// M3
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11-09-2018, 02:55 PM	#6
overlook637 Lieutenant 245 Rep 466 Posts Drives: M4 Join Date: Mar 2018 Location: USA iTrader: (0)	Sound clips will be after ceramic coating.
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11-09-2018, 03:06 PM	#7
jpsimon Team Zissou 3065 Rep 10,197 Posts Drives: 2022 AWD M3 Comp - SMB Join Date: Dec 2006 Location: CT iTrader: (7)	Definitely post a sound clip once this is done!
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11-10-2018, 12:56 AM	#8
mynameisplayer SCHNELL 226 Rep 835 Posts Drives: F15 50i, E46, E90, Crafter van Join Date: May 2016 Location: Australia iTrader: (0)	Very interested to hear - common trick removing the cat innards on every other tuned car, keen to see what it'll do on the F80.
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11-30-2018, 06:42 PM	#10
overlook637 Lieutenant 245 Rep 466 Posts Drives: M4 Join Date: Mar 2018 Location: USA iTrader: (0)	Ceramic Coating from SwainTech was 165$. Pictures coming next week. Videos by next weekend.
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12-19-2018, 04:09 PM	#11
overlook637 Lieutenant 245 Rep 466 Posts Drives: M4 Join Date: Mar 2018 Location: USA iTrader: (0)	Sounds great so far. Before the car had been tuned for all open flaps with resonator swap. The sound quality was ok and the volume was about right. Now it seams like there is less volume inside the car with a much improved sound quality. Zero drone. So far my buddy is happy.. The downpipe with 2 staggered halves were modified with 2 half inch holes drilled out per section. Looked like the 2 full half pipes would cause too much restriction. The extra holes should equal out the gas flow. Video to be posted at later date.
	Appreciate 0 Quote