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      08-28-2011, 05:32 PM   #45
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I never hate and I love to learn new shit but I dislike heavily when haters try to tell me random shit I either already know or dont care to know...
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      08-28-2011, 05:46 PM   #46
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      08-29-2011, 02:22 PM   #47
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Helmets save lives. Loud pipes just make you an a-hole :-)
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      08-29-2011, 07:47 PM   #48
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Helmets save lives. Loud pipes just make you an a-hole :-)
Obviously, you do not ride. I'm not a fan of loud bikes, but I certainly don't like riding a bike that no-one knows is there. A helmet won't prevent a broken neck or various other injuries when someone turns into you. It'll just give your brain a fighting chance.
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      08-30-2011, 04:55 AM   #49
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Yet another douche bag cop. Simple minded dolts that somehow pass the civil service exam.

I personally believe that many loud bike riders are DBs themselves, but there is a prevalent logic that "loud pipes save lives". I'm a believer in that philosophy, but still try not to upset folks if I can avoid it. This cop just bunches all loud bike riders into one group because he's too simple minded to evaluate more than one factor at a time.
There is "prevalent logic" by Harley riders who like loud pipes; those same bikers will tell you that it's dangerous to wear a helmet because there is "prevalent logic" that a helmet strap will kill you. In reality, they want to ride a loud bike without a helmet and rationalize it. Let's not confuse herd mentality with actual facts, and there is no evidence that loud pipes save lives, at least not by any unbiased party.

I personally believe that people can and should do whatever they want. I really don't care--up to the point when it affects me. And if I'm sleeping in on some Saturday morning when some DB with a modded M3 exhaust or some Harley rider with straight pipes goes for a cold start, it affects me. Clearly, LED rings, coil overs, CF goodies, etc, make no difference to me, so enjoy. But your "right" to enjoy a loud engine, make more power, whatever other justification you invent to rationalize your "right" ends when it impacts me.

So, do what you want, but save your moral indignation for the times when (1) you're not breaking the law, technically or otherwise; and (2) you're not affecting others' right to enjoy their space. Obviously, some people are unreasonable in what offends them, which is why we have noise ordinances that establish an objective standard. If you meet those rules, then I have no complaints.

And yes, I ride.
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      08-30-2011, 06:14 AM   #50
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Originally Posted by serranot View Post
There is "prevalent logic" by Harley riders who like loud pipes; those same bikers will tell you that it's dangerous to wear a helmet because there is "prevalent logic" that a helmet strap will kill you. In reality, they want to ride a loud bike without a helmet and rationalize it. Let's not confuse herd mentality with actual facts, and there is no evidence that loud pipes save lives, at least not by any unbiased party.

I personally believe that people can and should do whatever they want. I really don't care--up to the point when it affects me. And if I'm sleeping in on some Saturday morning when some DB with a modded M3 exhaust or some Harley rider with straight pipes goes for a cold start, it affects me. Clearly, LED rings, coil overs, CF goodies, etc, make no difference to me, so enjoy. But your "right" to enjoy a loud engine, make more power, whatever other justification you invent to rationalize your "right" ends when it impacts me.

So, do what you want, but save your moral indignation for the times when (1) you're not breaking the law, technically or otherwise; and (2) you're not affecting others' right to enjoy their space. Obviously, some people are unreasonable in what offends them, which is why we have noise ordinances that establish an objective standard. If you meet those rules, then I have no complaints.

And yes, I ride.
Very well written, but I think it is difficult to argue that waking Mrs. Minivandriver from her texting stuper is not a safer condition than humming up quietly beside her. I'm no fan of obnoxious Harley riders; no amount of noise will save many of them from their own stupidity; I just get upset at the types that lump all loud pipes into the same category as the dolt that revs his loud engine on Sunday morning in a residential neighborhood.
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      08-30-2011, 06:37 AM   #51
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Very well written, but I think it is difficult to argue that waking Mrs. Minivandriver from her texting stuper is not a safer condition than humming up quietly beside her.
Sure, but then that seems somewhat arbitrary. I mean, it might technically be safer if I could shoot jolts of electricity out of the front of my car toward people who appear to be driving while not paying attention to the road and their surroundings. But even if that were the case, it doesn't mean that everyone who I zap actually deserves it. I am invariably going to unjustly shock as many folks as I justly do.

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I'm no fan of obnoxious Harley riders; no amount of noise will save many of them from their own stupidity; I just get upset at the types that lump all loud pipes into the same category as the dolt that revs his loud engine on Sunday morning in a residential neighborhood.
I see your point. I would say that good judgement should prevail. For those that lack it, it doesn't matter what vehicle they have or anything else for that matter. They are going to be douche's at some point.
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      08-31-2011, 07:00 PM   #52
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Originally Posted by Radiation Joe View Post
Yet another douche bag cop. Simple minded dolts that somehow pass the civil service exam.

there is a prevalent logic that "loud pipes save lives". I'm a believer in that philosophy, . This cop just bunches all loud bike riders into one group because he's too simple minded to evaluate more than one factor at a time.
It appears someone has an inferiority complex and an anger issue.

First of all the modified exhaust is illegal.

Secondly this "simple-minded dolt' had a 20 year career as a police officer. This "simple-minded dolt" also has a degree in physics and electrical engineering and currently has a second career as a hardware engineering group manager at one of the country's largest defense contractors.

The fact that you believe in the philosophy that loud bikes are safe bikes just goes to show how little you do know. Sound waves travel in a straight line, with the wave widening as it moves from the source. The waves do not magically loop around to the front of the bike. The loud exhaust can only be heard from behind the bike. Reflections of the wave can be heard at other locations. You hear the loud exhaust after the bike passes you, not as it approaches you.

Essentially bikers like to pull the "loud bikes are are bikes" card out to try and not appear to be complete tools.

Oh and about those loud exhaust tickets; it did not cost me a dime to hand them out and you are going to have to do a lot better that call me names to hurt my feelings.

Thirdly, just to fire you up a bit more, this "simple-minded dolt" is currently collecting a generous pension from his police service and a salary from his current employer, who also offers a pension and 401K.

If that makes me a simple-minded dolt I can live with that.
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      08-31-2011, 07:55 PM   #53
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Originally Posted by Dave IV View Post
It appears someone has an inferiority complex and an anger issue.

First of all the modified exhaust is illegal.

Secondly this "simple-minded dolt' had a 20 year career as a police officer. This "simple-minded dolt" also has a degree in physics and electrical engineering and currently has a second career as a hardware engineering group manager at one of the country's largest defense contractors.

The fact that you believe in the philosophy that loud bikes are safe bikes just goes to show how little you do know. Sound waves travel in a straight line, with the wave widening as it moves from the source. The waves do not magically loop around to the front of the bike. The loud exhaust can only be heard from behind the bike. Reflections of the wave can be heard at other locations. You hear the loud exhaust after the bike passes you, not as it approaches you.

Essentially bikers like to pull the "loud bikes are are bikes" card out to try and not appear to be complete tools.

Oh and about those loud exhaust tickets; it did not cost me a dime to hand them out and you are going to have to do a lot better that call me names to hurt my feelings.

Thirdly, just to fire you up a bit more, this "simple-minded dolt" is currently collecting a generous pension from his police service and a salary from his current employer, who also offers a pension and 401K.

If that makes me a simple-minded dolt I can live with that.
lol
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BMW have tapped into this by mirroring typical BMW dynamics and steering communication within the new UKL cars.
You mean massive body roll, a steering system that is not connected to the front wheels, and the engine note played through the speaker system?!?!?!?!
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      08-31-2011, 08:33 PM   #54
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Quote:
Originally Posted by Dave IV View Post
It appears someone has an inferiority complex and an anger issue.

First of all the modified exhaust is illegal.

Secondly this "simple-minded dolt' had a 20 year career as a police officer. This "simple-minded dolt" also has a degree in physics and electrical engineering and currently has a second career as a hardware engineering group manager at one of the country's largest defense contractors.

The fact that you believe in the philosophy that loud bikes are safe bikes just goes to show how little you do know. Sound waves travel in a straight line, with the wave widening as it moves from the source. The waves do not magically loop around to the front of the bike. The loud exhaust can only be heard from behind the bike. Reflections of the wave can be heard at other locations. You hear the loud exhaust after the bike passes you, not as it approaches you.

Essentially bikers like to pull the "loud bikes are are bikes" card out to try and not appear to be complete tools.

Oh and about those loud exhaust tickets; it did not cost me a dime to hand them out and you are going to have to do a lot better that call me names to hurt my feelings.

Thirdly, just to fire you up a bit more, this "simple-minded dolt" is currently collecting a generous pension from his police service and a salary from his current employer, who also offers a pension and 401K.

If that makes me a simple-minded dolt I can live with that.
That in itself doesn't make you a simple minded dolt; stating that you wrote up every modified exhaust you encountered makes you simple minded. It's called a lack of discretion. Welcome to the same world as our friend who drives 65 mph in the #1 lane and feels he has every right to be there regardless of how many people pile up behind him. I'm also glad to hear you got a job with a defense contractor. Nothing like working for a company that makes money no matter how inefficiently they operate. Perhaps you'll go to work for a cigarette company next.

I don't have an inferiority complex. I understand that I'm inferior to many people. I just don't feel inferior to the simple minded dolts that make up a large percentage of our law enforcement community. Why don't you try to redeem yourself and tell us what percentage you believe shouldn't be carrying a badge? It's a rare department that doesn't have a percentage that would shock the average person.

I'm no amateur in the field of acoustics. I've been presenting the results of acoustic resonance calculations and showing the empirical evidence of same within the nuclear industry for years. As you should know, low frequency sound waves, like the exhaust beats from a low reving twin cylinder engine like a Harley, DON'T TRAVEL IN STRAIGHT LINES. Do you think they shoot out of the rear of the bike like a gun? They do "magically loop around to the front of the bike", if you want to put it that way. You'd have an argument if a Harley had 8 cylinders and revved to 8k rpm, but it wouldn't be a good one.

Care to impress us some more with your knowledge and history in law enforcement?
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      08-31-2011, 08:37 PM   #55
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OP, you should have rev'd your engine loud, then ram the basterd, get out and smack him for being an old fart that can't mind his own business.

Ok, maybe the raming and beating part might be a little over board but wouldn't it be nice to shut people up like that for good? lol!
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      08-31-2011, 08:38 PM   #56
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Quote:
Originally Posted by Dave IV View Post
It appears someone has an inferiority complex and an anger issue.

First of all the modified exhaust is illegal.

Secondly this "simple-minded dolt' had a 20 year career as a police officer. This "simple-minded dolt" also has a degree in physics and electrical engineering and currently has a second career as a hardware engineering group manager at one of the country's largest defense contractors.

The fact that you believe in the philosophy that loud bikes are safe bikes just goes to show how little you do know. Sound waves travel in a straight line, with the wave widening as it moves from the source. The waves do not magically loop around to the front of the bike. The loud exhaust can only be heard from behind the bike. Reflections of the wave can be heard at other locations. You hear the loud exhaust after the bike passes you, not as it approaches you.

Essentially bikers like to pull the "loud bikes are are bikes" card out to try and not appear to be complete tools.

Oh and about those loud exhaust tickets; it did not cost me a dime to hand them out and you are going to have to do a lot better that call me names to hurt my feelings.

Thirdly, just to fire you up a bit more, this "simple-minded dolt" is currently collecting a generous pension from his police service and a salary from his current employer, who also offers a pension and 401K.

If that makes me a simple-minded dolt I can live with that.
I'm with this guy. Excellent response.
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      08-31-2011, 08:42 PM   #57
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lol
Ha! Ha!
I respect your right to ask me to show some respect.

Just not for douchebags.
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      08-31-2011, 09:12 PM   #58
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      08-31-2011, 09:33 PM   #59
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Hahahaha pic of the year.

I was actually in the same boat the other night; just couldn't give it up because some d-bag was telling me I should have bought an E93 because i optioned my 92 with a moon roof.

In the end I was like F it. Let Natural Selection take care of these fuckers.
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      08-31-2011, 09:42 PM   #60
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I'm no amateur in the field of acoustics. I've been presenting the results of acoustic resonance calculations and showing the empirical evidence of same within the nuclear industry for years. As you should know, low frequency sound waves, like the exhaust beats from a low reving twin cylinder engine like a Harley, DON'T TRAVEL IN STRAIGHT LINES. Do you think they shoot out of the rear of the bike like a gun? They do "magically loop around to the front of the bike", if you want to put it that way. You'd have an argument if a Harley had 8 cylinders and revved to 8k rpm, but it wouldn't be a good one.
Acoustic waves DO travel in straight lines in air. Acoustic waves in air travel by compression and rarefaction of the air molecules in the wave's direction of travel. With respect to a vehicle's exhaust the waves emanate from a pipe (aka waveguide) that gives the waves direction. The waves DO NOT make a U-turn when they leave the (tail)pipe.

Anecdotal evidence of this principal is someone cupping their hands around their mouth to direct their speech (sound waves) toward another person who is out of normal hearing distance. This would not work if some of the energy in the sound waves made a u-turn as it exited the cupped hands (short pipe, waveguide) and traveled behind the caller. A more elegant example are the waveguides placed on stadium loudspeakers to direct the sound in the desired direction (for reference search EIRP- Equivalent Isotropic Radiating Power).

The only way sound waves will get redirected from their course of straight line travel (they actually travel in a conical pattern, which is determined by the aperture of the source) is by being reflected at boundaries of differing acoustical impedances.

Next, the source of the sound is irrelevant; be it a 2 cylinder motorcycle engine, an 8 cylinder car engine, an audio loudspeaker, or any other transducer. In any of these cases a mechanical device is putting air molecules in motion and as described above; acoustic waves in air travel by compression and rarefaction of the air molecules. The air molecules don't care what mechanical source put them in motion.

Maybe you are mistaking identifying a sound wave's source relative to its frequency and waves magically making u-turns in free space. As frequencies become lower they become more omnidirectional, meaning it becomes more difficult to identify the point of the source.

So, The short answer here is:
1) You are wrong.
2) Acoustic waves in air DO travel in straight lines.
3) Acoustic waves in air DO NOT magically make u-turns in free space.
4) Acoustic waves in air do not change direction until the encounter a boundary of a differing acoustical impedance.

If you disagree, add something meaningful, not just a " nah, nah, cause my mother said so". Oh, and calling me names is not going to have any effect, it only helps to discredit you.
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      08-31-2011, 10:43 PM   #61
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Quote:
Originally Posted by Dave IV View Post
Acoustic waves DO travel in straight lines in air. Acoustic waves in air travel by compression and rarefaction of the air molecules in the wave's direction of travel. With respect to a vehicle's exhaust the waves emanate from a pipe (aka waveguide) that gives the waves direction. The waves DO NOT make a U-turn when they leave the (tail)pipe.

Anecdotal evidence of this principal is someone cupping their hands around their mouth to direct their speech (sound waves) toward another person who is out of normal hearing distance. This would not work if some of the energy in the sound waves made a u-turn as it exited the cupped hands (short pipe, waveguide) and traveled behind the caller. A more elegant example are the waveguides placed on stadium loudspeakers to direct the sound in the desired direction (for reference search EIRP- Equivalent Isotropic Radiating Power).

The only way sound waves will get redirected from their course of straight line travel (they actually travel in a conical pattern, which is determined by the aperture of the source) is by being reflected at boundaries of differing acoustical impedances.

Next, the source of the sound is irrelevant; be it a 2 cylinder motorcycle engine, an 8 cylinder car engine, an audio loudspeaker, or any other transducer. In any of these cases a mechanical device is putting air molecules in motion and as described above; acoustic waves in air travel by compression and rarefaction of the air molecules. The air molecules don't care what mechanical source put them in motion.

Maybe you are mistaking identifying a sound wave's source relative to its frequency and waves magically making u-turns in free space. As frequencies become lower they become more omnidirectional, meaning it becomes more difficult to identify the point of the source.

So, The short answer here is:
1) You are wrong.
2) Acoustic waves in air DO travel in straight lines.
3) Acoustic waves in air DO NOT magically make u-turns in free space.
4) Acoustic waves in air do not change direction until the encounter a boundary of a differing acoustical impedance.

If you disagree, add something meaningful, not just a " nah, nah, cause my mother said so". Oh, and calling me names is not going to have any effect, it only helps to discredit you.


Classic example of subterfuge. Sound waves can be made to travel in straight lines if the source is very small and positioned at the focal point of parabolic reflector. Hardly the conditions of a Harley exhaust. Otherwise, they are omnidirectional. How can you even argue this point?

If what you are stating was correct or even partially correct, we could hardly hear a motorcycle that was facing us. Completely to the contrary, the damn things are obnoxiously loud no matter where you stand in relation to them. Yes, they are louder directly behind, but you stated it was due to reflection that we hear them anyplace but directly in the path of the exhaust. Really??????

Tell us again how you manage a group of engineers at a defense contractor. Not a huge surprise as I encountered plenty of clueless managers at Lockheed during my short stint watching them destroy a viable company they absorbed.

By the way, the majority of sound waves are refracted at boundaries of differing acoustical impedance, not reflected. Please stop trying to confuse us with jargon.
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      08-31-2011, 10:58 PM   #62
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Berkeley grad?
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      08-31-2011, 11:29 PM   #63
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this is pretty comical
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      09-01-2011, 10:01 AM   #64
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I'm with Joe. Last time I checked base was non-directional (thus the need for only one speaker in a home theater setup) and treble tones are directional. The lower pitched the tone the more likely it is to travel in all directions.

I don't agree on the loud pipes save lives thing though. I think they just like the pipes and are looking for some practical excuse for them. The only time I hear them coming is when they are right next to me. That is usually when they decide to rev the engine and scare the crap out of me as they are cutting lanes in traffic. The douche bag attitude of these folks is that everyone in traffic should be constantly checking their mirrors for bikes cutting lanes and move over or they will rev the bike right next to your car.

Sorry, but so many of these folks are insanely self centered.
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      09-01-2011, 10:53 AM   #65
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Originally Posted by Radiation Joe View Post
Sound waves can be made to travel in straight lines if the source is very small and positioned at the focal point of parabolic reflector. Hardly the conditions of a Harley exhaust. Otherwise, they are omnidirectional. How can you even argue this point?

If what you are stating was correct or even partially correct, we could hardly hear a motorcycle that was facing us. Tell us again how you manage a group of engineers at a defense contractor. Not a huge surprise as I encountered plenty of clueless managers at Lockheed during my short stint watching them destroy a viable company they absorbed.

By the way, the majority of sound waves are refracted at boundaries of differing acoustical impedance, not reflected. .

Refraction! Really? Refraction is the change in direction of a wave due to impedance changes in a medium or between mediums. For acoustic waves in the atmosphere refraction is typically be due to a temperature lapse (decreasing temp with increasing altitude) or temperature inversion (increasing temp with increasing altitude), which will cause an acoustic wave to bend upward or downward. It will not cause the wave to bend vertically (front to back). Reflection dwarfs refraction in the context we are discussing and it will never cause the wave to “wrap around” the motorcycle.

Your statement about point sources and parabolic reflectors is the first semi-correct statement you have made. Given a point source I can direct a wave in any direction I desire by manipulating the reflector. I can also widen or narrow its beam and manipulate its amplitude (again, search EIRP).

It seems that the fundamental mistake you are making is that you believe the source of the acoustic wave is at the opening of the motorcycle’s exhaust pipe. This is wrong. The source of the wave is the combustion that takes place in the engine. For the purpose of this discussion we will consider the combustion to be a point source that radiates an acoustic wave equally in all directions. Ahh, now we introduce the reflector…the combustion chamber acts as a reflector, directing the wave in one direction; through the exhaust valve. The wave then enters the exhaust pipe which acts as a waveguide. As the exhaust (an acoustic wave) exits the pipe it is directed toward the rear of the bike.

As mentioned earlier, acoustic waves in air travel by compression and rarefaction of the air molecules in the wave's direction of travel. Put your hand near to the opening of the exhaust pipe. You can feel the acoustic wave (the exhaust). As you move your hand further from the pipe opening the intensity of the wave decreases. If you place your hand to the side of the pipe, adjacent to the opening, you will not feel an acoustic wave (take care not to touch the pipe and confuse the vibration of the pipe with the acoustic wave).

In short, the acoustic wave travels in a conical straight line from the exhaust pipe, to the the rear of the bike. There is no magical property causing the wave to “make a U-turn or wrap around” the bike. If you are observing the bike while you and the bike are stationary you will hear the loud exhaust while standing in front of the bike. This is due to reflections (NOT refraction) of the wave from objects near the bike. Once the bike is moving the effect of the reflections is minimized and the loud exhaust will be almost entirely noticeable only from the rear of the bike.

The argument that a loud bike is a safe bike is a load of crap, unless someone is going to run you over from behind. On the other hand someone may intentionally run you over from behind for having a loud, obnoxious bike.
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      09-01-2011, 11:07 AM   #66
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Originally Posted by Pointerman View Post
I'm with Joe. Last time I checked base was non-directional (thus the need for only one speaker in a home theater setup) and treble tones are directional. The lower pitched the tone the more likely it is to travel in all directions.

.

At lower frequencies acoustic waves become more omni-directional, which means it gets more difficult to pinpoint its source. It does not necessarily mean that it radiates in all direction from the source.

In a home audio system a single sub-woofer cabinet will perform well because of the onmi-directional nature of the bass frequencies. The more uni-directional nature of the higher frequencies require two sources interacting through constructive/destructive interference to provide imaging and sound-staging that stereo reproduction is designed to create .
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