Carbon Filter Delete

David R said:
I am an old BMW rider. I like quiet bikes.

David
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I agree with all that you've posted. Gutting or removing the "cats" would probably not result in a big performance gain and I'd bet a bunch of $$$ that the bike's "computer" would have a fit. But, while I like a quiet bike, I would like to hear something back there. The darned exhaust note is so quiet that I hear nothing above 30 MPH. My Indian, which has stock exhaust is much louder than the BMW R18. I was thinking that uncorking the cats would result in a small improvement in exhaust note.
 
Yeah me too, but I would appreciate a deeper sound since the Berlin designers were trying to copy the classic HD paradigm with vibration, chrome, etc., it is a little disappointing to have a put-put type of exhaust note when we all know the Boxer engine can produce a deep, mellow base cadence. I still love the looks and feel of an open air cruiser that is very comfortable winding out to the NorCal coast at almost legal speeds. It’s a great counterpoint to my V4S!
 
dfinkelsteinmd said:
Yeah me too, but I would appreciate a deeper sound since the Berlin designers were trying to copy the classic HD paradigm with vibration, chrome, etc., it is a little disappointing to have a put-put type of exhaust note when we all know the Boxer engine can produce a deep, mellow base cadence. I still love the looks and feel of an open air cruiser that is very comfortable winding out to the NorCal coast at almost legal speeds. It’s a great counterpoint to my V4S!
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They had to cope with Euro 5 regulation.
That's already quite a performance they could make such an engine complying to it !
I'm personally satisfied with the noise, very discreet at low charge, and then much more present with the throttle up ! :LOL:
 
Gerard said:
They had to cope with Euro 5 regulation.
That's already quite a performance they could make such an engine complying to it !
I'm personally satisfied with the noise, very discreet at low charge, and then much more present with the throttle up ! :LOL:
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Are you folks in Europe even allowed to swap the exhaust to something from the aftermarket? In 20 years of traveling to the Geneva area, virtually every bike that I saw had stock exhaust.
 
Out curiosity, what is the maximum Decibel reading allowed?
I do have a Db meter and my custom exhaust register 84 Db at 2400 RPM 6ft(2 meters).
 
Do those here who would prefer louder pipes ride with ear plugs? If yes, the hell do you care how loud your pipes are? If no, man, eventually ALL pipes will seem quiet.:unsure:

/I wouldn't mind if the stock exhaust was a little louder
//still not shelling out $1500 for slip-on's with no character
 
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Gerard said:
They are currently testing sound "radars" paired with cameras, creating automatic fines ...
Welcome in Europe ! 🤣
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OUCH!
I would hate to be at the mercy of a cop with a sound meter. It's so easy to alter the reading with minor changes in position. The American Motorcyclist Association tried to establish a uniform method of measuring the sound pressure of an exhaust system years ago, so that police and racing officials (anyone with a meter) could get reliable results. As I recall, the usual presumption of a measurement at 90-degrees to the side of the exhaust outlet and some fixed distance (6 ft.?) away was their recommendation. But uniformity among different humans was not as simple as we would like. Moving the meter a foot toward the front of the bike, toward the rear, away or closer to the exhaust outlet can change the result dramatically. And also, when some machines have a single muffler and others have two (or more), it gets messy.
To even consider some way to measure the sound pressure of a moving vehicle, at varying distances and PRESUME to issue citations with the results... lawyers would have a field day with that one.
 
TodkaVonic said:
Do those here who would prefer louder pipes ride with ear plugs? If yes, the hell do you care how loud your pipes are? If no, man, eventually ALL pipes will seem quiet.:unsure:

/I wouldn't mind if the stock exhaust was a little louder
//still not shelling out $1500 for slip-on's with no character
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ABSOLUTELY! I would just like to hear that my engine is running. Not to be deafened by it.
Man! I hate that ignorant old crap about loud pipes saving lives.
 
I had a friend who, after we had a conversation that made it plain that we didn't share the same point of view, would say, "Yeah. Well... that's just YOUR opinion!"
To that I usually replied, "What else am I supposed to give... YOUR opinion? HAH!"
 
Black Dog said:
Out curiosity, what is the maximum Decibel reading allowed?
I do have a Db meter and my custom exhaust register 84 Db at 2400 RPM 6ft(2 meters).
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It depends on where you live - 90 dBA in South Africa for instance. I reckon your dB meter is either shot or in urgent need of calibration. Phone-based dB apps are useless, and each will provide another set of values. And a reading at 2400 rpm is of no value if taken with the bike on its side stand, and the engine under no-load.

An increase of 3dB doubles the sound intensity, but a 10dB increase is twice as loud. Also, note that dB sound pressure levels are unweighted while dBA levels are "A"-weighted according to weighting-curves approximating how the human ear perceives sound.
 
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TodkaVonic said:
Do those here who would prefer louder pipes ride with ear plugs? If yes, the hell do you care how loud your pipes are? If no, man, eventually ALL pipes will seem quiet.:unsure:

/I wouldn't mind if the stock exhaust was a little louder
//still not shelling out $1500 for slip-on's with no character
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There is a pronounced improvement in exhaust note and volume if one cracks open the throttle when, say, putting along in second gear. Who will be the first to remove the (assumed) butterfly flaps from the exhaust valves fitted just downstream of the second set of oxygen sensors? Removing only the motors will most likely result in a CEL on the dash and probably leave the butterflies closed permanently. It looks like it will require cutting the headers on an existing weld-seam and rewelding - BMW very cleverly reduced the header bores downstream of the valves, probably anticipating this modification. The required cut will transpire behind the exhaust shield, so it will neither ruin the exhaust nor its aesthetics.

I doubt that removing it will affect performance - the R18's exhaust valves were clearly intended to appease and obtain EURO-5 certification. Ducati always contended that their exhaust valves were 'tuned' for maximum performance across the rev-range. especially during all the years that the fuelling on their bikes s4cked (?)
 
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Looking at the parts sheet. I didn't know about the flap. My R1200R has it. I unhooked it and had some small running issues under light throttle, so I hooked it back up. All I had to do is unhook the cable from the valve inside the housing. I can understand why it worked and why I had light throttle issues.

David
 
THIS is a big reason why I love being on a forum like this one. I learn lots of great stuff from you guys!
I've had a bunch of motorcycles before, but the R18 is my first modern BMW and I did not know until now that BMW was installing valves in the exhaust systems. They are apparently much like the EXUP valves first devised by Yamaha. And I'll bet that there are few, if any, benefits to messing with them.
 
estoma said:
There is a pronounced improvement in exhaust note and volume if one cracks open the throttle when, say, putting along in second gear. Who will be the first to remove the (assumed) butterfly flaps from the exhaust valves fitted just downstream of the second set of oxygen sensors? Removing only the motors will most likely result in a CEL on the dash and probably leave the butterflies closed permanently. It looks like it will require cutting the headers on an existing weld-seam and rewelding - BMW very cleverly reduced the header bores downstream of the valves, probably anticipating this modification. The required cut will transpire behind the exhaust shield, so it will neither ruin the exhaust nor its aesthetics.

I doubt that removing it will affect performance - the R18's exhaust valves were clearly intended to appease and obtain EURO-5 certification. Ducati always contended that their exhaust valves were 'tuned' for maximum performance across the rev-range. especially during all the years that the fuelling on their bikes s4cked (?)
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Who will be the first to remove the loose nut behind the wheel?
 
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