Annoying Sound With Full Akrapovic Evo Line + Akra Catless Downpipes

AlexVDW · 06-08-2015, 10:35 AM

Hi guys,

I have the full Akrapovic evolution line + Akrapovic downpipes installed on my F80 M3. When driving in efficient mode with the exhaust valves closed I always hear a very annoying raspy noise below 4000 rpm. When I step on the gas and the valves open it’s gone.
In sport mode it’s also less noticeable because the exhaust valves open at lower rpm.
Has anyone experienced the same problem or is this normal with the full Akrapovic setup?

Greetings,

Alex

Daft · 06-08-2015, 12:20 PM

Got a sound clip? I plan on getting this exact exhaust setup in the future. That is, when I eventually get my M4..

danielxzy · 06-08-2015, 01:07 PM

Its normal, all ak evo+ donwpipe has this noise as far as I know. Use Macht Schnell EVC module, you will no longer has this noise as long as the valve is open.

ES_TRADER · 06-09-2015, 08:28 AM

I leave my valves open and unplugged 100% of the time and I hear no odd noise whatsoever

8600RPM · 06-10-2015, 09:27 PM

I had tried this with my MPE awhile back when I unplugged the valves and left them closed instead of open. You get a really annoying terrible sound. Not a good rasp but a really bad sounding rasp. So I am guessing its just too much exhaust gas flowing through the muffler not designed to really take that much exhaust gas since at higher rpm the stock logic opens valves in any mode.

Mario_Kart · 06-10-2015, 09:48 PM

Quote:

Originally Posted by 8600RPM

I had tried this with my MPE awhile back when I unplugged the valves and left them closed instead of open. You get a really annoying terrible sound. Not a good rasp but a really bad sounding rasp. So I am guessing its just too much exhaust gas flowing through the muffler not designed to really take that much exhaust gas since at higher rpm the stock logic opens valves in any mode.

you are doing it wrong. everyone is unplugging it so it stays open and not closed.

8600RPM · 06-10-2015, 10:51 PM

I understand. I was playing around when I was thinking about downpipes in the past to just see if it was viable option to have them closed at High rpm but I got my answer which was it sounds terrible

06-08-2015, 10:35 AM	#1
AlexVDW Registered 0 Rep 1 Posts Drives: BMW M3 F80 Join Date: Jun 2015 Location: Belgium iTrader: (0)	Annoying Sound With Full Akrapovic Evo Line + Akra Catless Downpipes Hi guys, I have the full Akrapovic evolution line + Akrapovic downpipes installed on my F80 M3. When driving in efficient mode with the exhaust valves closed I always hear a very annoying raspy noise below 4000 rpm. When I step on the gas and the valves open it’s gone. In sport mode it’s also less noticeable because the exhaust valves open at lower rpm. Has anyone experienced the same problem or is this normal with the full Akrapovic setup? Greetings, Alex
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06-08-2015, 12:20 PM	#2
Daft Major 384 Rep 1,203 Posts Drives: 2021 M2C Join Date: Jan 2009 Location: Ontario, Canada iTrader: (2) Garage List 2021 BMW M2 Competi ... [10.00]	Got a sound clip? I plan on getting this exact exhaust setup in the future. That is, when I eventually get my M4..
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06-08-2015, 01:07 PM	#3
danielxzy New Member 3 Rep 15 Posts Drives: m4 Join Date: Oct 2014 Location: Hangzhou iTrader: (0)	Its normal, all ak evo+ donwpipe has this noise as far as I know. Use Macht Schnell EVC module, you will no longer has this noise as long as the valve is open.
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06-09-2015, 08:28 AM	#4
ES_TRADER Colonel 344 Rep 2,928 Posts Drives: 328i, 335i, M3, 535i, X5, 36M Join Date: Oct 2010 Location: OC iTrader: (3) Garage List 2014 Ford Raptor [0.00] 2012 328i E92 [10.00] 2013 X5 [0.00] 2013 335i F30 [8.00] 1990 Toyota Previa [0.00] 1997 E36 M3 [10.00] 2011 E92 M3 [0.00] 2011 535i [0.00]	I leave my valves open and unplugged 100% of the time and I hear no odd noise whatsoever
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06-10-2015, 09:27 PM	#5
8600RPM Lieutenant Colonel 657 Rep 1,749 Posts Drives: e92 m3 Join Date: Oct 2014 Location: AZ iTrader: (0)	I had tried this with my MPE awhile back when I unplugged the valves and left them closed instead of open. You get a really annoying terrible sound. Not a good rasp but a really bad sounding rasp. So I am guessing its just too much exhaust gas flowing through the muffler not designed to really take that much exhaust gas since at higher rpm the stock logic opens valves in any mode.
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06-10-2015, 10:51 PM	#7
8600RPM Lieutenant Colonel 657 Rep 1,749 Posts Drives: e92 m3 Join Date: Oct 2014 Location: AZ iTrader: (0)	I understand. I was playing around when I was thinking about downpipes in the past to just see if it was viable option to have them closed at High rpm but I got my answer which was it sounds terrible
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