Why does MPE sound "mature" with miles?

dhoggm3 · 12-13-2015, 06:50 AM

Title pretty much says it.

I've had the MPE on for a few thousand miles now, and the sound has matured from being somewhat raspy into sounding more like an angrily tuned E46 M3. I'm loving the better sound.

My automotive engineer nephews who have speculated that some internal materials form a better bond as the MPE breaks in; this morphs a series of shorter internal lengths into one longer-length integrated run. Hence the deeper sound.

But that's just educated speculation. Does anyone know the real answer?

F83 · 12-13-2015, 07:21 AM

Might be the buildup of deposits inside. It's going to be bare metal initially, after a few thousand miles there will be loads of carbon deposits inside, perhaps making the metallic sound less intense. Just speculation on my part though.

teefive · 12-13-2015, 10:00 AM

Quote:

Originally Posted by F83

Might be the buildup of deposits inside. It's going to be bare metal initially, after a few thousand miles there will be loads of carbon deposits inside, perhaps making the metallic sound less intense. Just speculation on my part though.

Correct. Exhaust systems without fiberglass packing get slightly deeper, throatier, and less raspy with age because of this.

CaryTheLabelGuy · 12-13-2015, 02:52 PM

It is from the carbon buildup inside the exhaust and especially inside the muffler. My stock exhaust sounds totally different now than it did when it was new. It currently has almost 8k miles on.

Mike@N54Tuning.com · 12-13-2015, 04:24 PM

Quote:

Originally Posted by CaryTheLabelGuy

It is from the carbon buildup inside the exhaust and especially inside the muffler. My stock exhaust sounds totally different now than it did when it was new. It currently has almost 8k miles on.

+1

Mike

shortseller · 12-14-2015, 03:49 PM

Quote:

Originally Posted by CaryTheLabelGuy

It is from the carbon buildup inside the exhaust and especially inside the muffler. My stock exhaust sounds totally different now than it did when it was new. It currently has almost 8k miles on.

Just turned over 9k with mine and have experienced the same outcome. No more immediate need to replace with aftermarket anymore as it sounds good as is.

CaryTheLabelGuy · 12-14-2015, 04:46 PM

Quote:

Originally Posted by shortseller

Just turned over 9k with mine and have experienced the same outcome. No more immediate need to replace with aftermarket anymore as it sounds good as is.

Yup. It is deeper and has more rumble and a lot less rasp.

tareemaa · 12-14-2015, 07:27 PM

Beautiful exhaust, I'm loving every mile of it

mike@x-ph.com · 12-18-2015, 01:35 PM

It is not exhaust specific. All exhaust tones will change after couple hundred miles for the reasons posted above

Brasko · 12-19-2015, 10:03 AM

Interesting input from everyone. I'm having the dealer install the MPE system when my M3 arrives. I'll try to capture some exhaust tones before breaking it in for comparison.

dhoggm3 · 12-19-2015, 11:30 AM

Thanks all! Carbon buildup was not an angle I had considered. Makes sense.

12-13-2015, 06:50 AM	#1
dhoggm3 Major 269 Rep 1,282 Posts Drives: 850i C, Gated R8 5.2, E63 Join Date: Jul 2007 Location: Central PA iTrader: (1)	Why does MPE sound "mature" with miles? Title pretty much says it. I've had the MPE on for a few thousand miles now, and the sound has matured from being somewhat raspy into sounding more like an angrily tuned E46 M3. I'm loving the better sound. My automotive engineer nephews who have speculated that some internal materials form a better bond as the MPE breaks in; this morphs a series of shorter internal lengths into one longer-length integrated run. Hence the deeper sound. But that's just educated speculation. Does anyone know the real answer? __________________ M850i Vert with RaceChip E46 M3, Euro Headers, Rasp Pipe, Kassel Tune Alpina B8, zero performance mods
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12-13-2015, 02:52 PM	#4
CaryTheLabelGuy Colonel 2634 Rep 2,809 Posts Drives: 2016 M4 ZCP Join Date: Mar 2015 Location: Jacksonville, FL iTrader: (0)	It is from the carbon buildup inside the exhaust and especially inside the muffler. My stock exhaust sounds totally different now than it did when it was new. It currently has almost 8k miles on.
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12-14-2015, 07:27 PM	#8
tareemaa Bimmer Fanatic 368 Rep 1,660 Posts Drives: M3 Join Date: Mar 2011 Location: Chicago iTrader: (7)	Beautiful exhaust, I'm loving every mile of it
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12-18-2015, 01:35 PM	#9
mike@x-ph.com BimmerPost Supporting Vendor 24280 Rep 190,975 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	It is not exhaust specific. All exhaust tones will change after couple hundred miles for the reasons posted above __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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12-19-2015, 10:03 AM	#10
Brasko #LSBM3 1421 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]	Interesting input from everyone. I'm having the dealer install the MPE system when my M3 arrives. I'll try to capture some exhaust tones before breaking it in for comparison. __________________ /// M3
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12-19-2015, 11:30 AM	#11
dhoggm3 Major 269 Rep 1,282 Posts Drives: 850i C, Gated R8 5.2, E63 Join Date: Jul 2007 Location: Central PA iTrader: (1)	Thanks all! Carbon buildup was not an angle I had considered. Makes sense. __________________ M850i Vert with RaceChip E46 M3, Euro Headers, Rasp Pipe, Kassel Tune Alpina B8, zero performance mods
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