AMA on noise
 

FYI, AMA position paper on "louder than stock" motorcycle exhaust systems.

http://www.noiseoff.org/media/ama.motorcycle.noise.pdf

AMA has always been against excessive motorcycle noise. Just now laws are finally catching up. Sanctioned events motcross etc are testing and setting lower limits. 4 stroke bikes are loud as hell when uncorked. Ever sit on the line before a moto with 40 other whacko's on 250F's pinned wide open? The oems need to step up and make quieter bikes with the same power levels. **** a little power loss won't hurt them anyways, the modern 4 stroke is getting pretty crazy.

dcb -

I was soooo confused! I thought it was the *other* AMA, the American Medical Association, :D .

Eats bean A long day.

CarloSW2

I sure wouldn't mind quieter bikes. I live in Harley town USA, and 99% of the bikes I encounter I can hear from a mile away. At first you don't mind it, but when it never stops it starts to get annoying. Even the crotch rocket guys feel the need rip off the OEM mufflers and tear around everywhere.

I know the feeling. There's an annual Harley tourist thing here every fall. I live far enough from the major highway that I can barely hear normal traffic, but get a few thousand Harleys running up and down the road, and the noise level is unbearable even inside the house.

So far I've managed to get out of town on that weekend, but I dread the chance of a time when I can't. It'd be me on a hill with the AK-47 and about a thousand rounds.

It's something I don't understand at all: I've ridden motorcycles most of my life, but I always liked mine quiet. Even sold one Yamaha after a few weeks 'cause it was too loud. What makes people want to make noise like that? Is it just insecurity that makes them feel like big bad dudes 'cause they've got loud pipes?

"loud pipes save lives" has been a saying for years. Unofrtanately the AMA and many others(myself included) don't support that thinking. Until harley owners and sport bike riders alike get it through there pee brains that noise doesn't save your life noise restrictions will get tighter. California is crazy with banning OHV riding. Think about it there are places that you can't ride your atv,motorcycle on your pwn PRIVATE land! Its crazy I know Jeremy McGrath went to court over that, fighting for his right to ride. Personally I wish they made a law that all bikes had to be like 80 decibels at the tail pipe. have laws strictly enforced by taking offending bikes away/huge fines. Harleys have always annoyed me, loud sport bikes do at time s too. **** even Moto bikes can be annoying when idiots don't run packing in the silencer.

Yeah. And what compels all those a******s to remove packing/baffling?

People in the off road world are finally coming around to the noise issues, but I think it will be a long time before the street (*cough*Harley*cough*) crowd breaks tradition to accept it.

I'm part of an off road racing organization where we must pass sound check for every race. 96 dB is the current limit, because that's what Arizona law currently is. 4 strokes are DEFINETELY harder to pass than the 2 strokes. Most 4 strokes can barely squeek by, and any of the 4 stroke MX bikes need a quite silencer/tip to pass. We've had guys show up throwing 105-110 dB range. I am still amazed at the difference sound-wise between our races and going to the local MX. Some of those bikes are painfully loud there, because no one cares! Noise = power to most people!

Quite bikes can be done, but it's going to be hard to get the consumer to accept that. Yamaha made a big leap going to a mechanical muffler on the YZ450F, cutting sound a large amount. Guess what everyone does? Ditches that silencer for an aftermarket one, because you can get 3-4 hp that way. Never mind that test riders and guys in the know actually say you can pull faster lap times with the smoother, more linear power of the stock silencer. I at one time set my old KX125 up to be ubber quiet. Quiet silencer, airbox baffle, lots of foam everywhere (around airbox, above lid/baffle, under engine, etc). It actually blew only 78dB on the race mic. There was still a lot of sound coming from the expansion chamber, but it was a big impovement, and still had plenty of power for a B level off road racer.

Anyway, in 10 years we won't have to worry about this because either
A) All forms of recreational fun will be shut down
or
B) Electric bikes will catch on. KTM has one in the works, and I'm ready for it. :)

"Loud pipes save lives" is just an excuse to dink with the bike. Nobody can substantiate the claim that they save lives. It "justifies" spending $800 on customization to the wifey. I'm all for customization, but loudness is just too overdone these days, now it's just noise and obnoxious.

Personally, I'd rather have a low really good sound quality than lots of just plain noise.

One thing I thought I'd add.

Manufacturers aren't helping the noise issue either!!!!

Yamaha now puts a quiet silencer on their YZ450F. Everyone talks about how much quieter it is than the competition, yet it sound checks the loudest. Why? Because Kawasaki, Honda, and Suzuki would rather "cheat" the system than build a quiet bike. They use ignition timing to quiet things down when running higher rpms and no load. This means the quiet Yamaha might blow 100 dB, but the Kawasaki that is painfully loud only shows 95 dB on the meter. This does NOTHING to help us in the battle to quiet things down and save riding areas!

yeah sound testing is pretty much why there is ignition retarding and tall gears on all the sport bikes sold in the usa. you dont think supersports would be more fun if they were geared lower than 100mph in 1st gear? makes it so they can be reving low at 35mph, also there are usually butterfly valves in the mufflers to open up more "to increase or spread power"... yeah thats BS, they are just cheating the system. my bike had all that stuff, I disabled the ignition timing and it runs better all the time, it never had a butterfly valve, or at least not when I bought it (it had a pipe installed by the previous owner) but I have never read that they had them to begin with anyways.
of course, my bike does "have a pipe" on it, as in, a louder pipe purely for the sake of a louder pipe.... its not prettier, it doesnt give any more power, it does weigh about half as much and doesnt get hot like the OEM though, those are benefits. but its pretty much there to let the little V2 sound like a mean thing instead of a sewing machine. I'm thinking of inserting a sound reducer that I have seen for the model, though I havent been able to find it or even figure out how to order one, and I have tried.
now, if I am going to be building a new tail peice (for luggage and aero reasons) then I will integrate in a new muffler into it, and I may build a custom one, similar to a "twin loop muffler" for cars, only it will be triloop muffler, and be almost silent, whilest maybe giving better power. but again, we shall see

Adam, when i go racing my car some tracks have sound restrictions too. There are always 2 tests - standing still 1000rpm below redline, and flying test on the main straight from behind the pit wall. This would ensure that those bikes that tinker with timing under light load get tested properly while they are running.

80db is pretty fricken quiet as a peak noise. As a typical operating on the street noise, sure... but the 96dB mentioned above is a more reasonable peak. (of course, dB is proportional to distance of measure, so i guess i'm talkin out my ass. We do standing tests at 98dB 15ft behind the vehicle, and flying tests at 90dB 50ft to the side)

Open headers DOES make more power
 

Open headers (Loud exhaust) does make more power and make the motor more effecient. Still on my race car I run mufflers even though it is not required. They are huge 4 inch inside diameter and they are still pretty loud but much quieter then open headers.
To make a car quiet hurts performance and mileage but most people do not want the noise. There is no way around it if you make it quiet you will hurt the air flow, hurt performance, mileage and you will add weight to the vehicle. But you would not want to drive a car that loud and nobody could sleep. Open exhaust is definatly not the answer.
Many of the cars and motorcycles now are way too loud. I live about a mile from the highway and at night I can hear some of the bikes from there. That is too loud.
Horns will save lives just as well as loud pipes and a little louder than stock is fine. Open headers is not.
America is no longer the land of the Free. Everything is against the law and they are adding more laws every day. I hate to see them adding more noise laws but with the really loud bikes out there it will start happening more often. It is irresponsible to drive around with pipes that loud and it will only cause more problems and laws.
I think the AMA has a pretty good stance on the issue but would not want to see more laws to enforce it.

The problem here is that you, like so many other people, seem to see freedom as purely one-sided: you get to do whatever you want, and damn the rest of the world. Sorry, but I think that just as your freedom to swing your fist ends at the tip of my nose, so does your freedom to run loud pipes end at my ears.

Whoa! Hold on there!
 

I said open exaust is definatly NOT the answer. I do not like being woke up at 3:00 am by some motorcycle on the highway a mile away.

I do NOT run open exhaust even on my race car! I am alway respectful of other drivers and move over to let them by if they want by. I just do not like that some people have more "Freedoms" than others and that America basically has laws against everything. Stating a fact we are not the land of the Free any longer.

Also stating a fact that to make a car (or motorcycle) quiet it has a cost of performance, economy and weight. Fact.
I do not want laws passed to make changing pipes, intakes or anything else illegal to your vehicles. That is the whole reason for this web site is to discuss how to modify your vehicle to perform better for your needs. That does not mean I run open exhaust or want to hear others doing it. Still I want people to have the right to modify them. Create more laws and tax more to enforce them is not the answer in my opinion.
All car manufacturors make some concessions to get a car to perform and meet the customers needs and budget.

When Jane Goodall was studying chimpanzees in Uganda she noticed that the males would do a charging display aimed at the other males where they would run around and hoot and hollar and do everything they could to prove to the other male champs that they were the biggest, baddest chimp around. One of the young males discovered that if he rolled a couple of empty gas cans ahead of him as he did his display, their metallic clatter made a lot more noise than he could produce on his own and really intimidated the other males (and eventually allowed him to become the top male in his group).

Anyway, whenever I see some guy sitting in his modified-to-be-noisier ride, the image of that chimp comes to mind. The same primal urgings that drives the chimp to make his charging display are similar to the one that drives the young man to sit at the red light revving his loud engine. They both likely share a similar visceral motivation, an urge to want to intimidate the male competition. I know from my younger years, there can be something deeply gut satifying about rolling down the highway to the music of a loudly throbbing engine.

Exactly, making bikes to pass the sound check procedure, but not make them quieter in operation.

Dirt bikes are tested pre SAE 1287 spec. Basically it's holding the meter 20" from the exhaust outlet, at a 45 degree angle to the side of the outlet. The test is performed at rpm equal to 1/2 of peak power rpm. So if Honda rates your 250F to make peak power at 11,500 rpm, then you are sound checking at 5,750 rpm in neutral.

The problem isn't fully to blame on the manufacturers, a lot falls on the general public. Still too many people think loud = power, or safety. The YZ450F gets good reviews from magazines on it's power and lower sound level, yet I have yet to see one with a stock can in place. At one time I got in a bit of an argument with a Harley guy, who told me his friend was a moron. Friend got a new bike, and $1K towards accessories, which he spent on a leathers and a helmet. This guys thinks his friend was dumb and should have gotten pipes. His argument was that with a quite bike you are for sure going to get in an accident and need the leathers and helmet, but with a loud bike people will know you are there and you won't get in an accident. :rolleyes:

I think I'm one of the few that thinks electric dirt bikes are going to be great, once everything is worked out. I can see myself going with one once they are proven. There are many haters though.

Thanks!. That does a far better job of putting into words my thoughts about loud pipes and the people that run them than I could ever do myself.

As to the question of whether adequate mufflers actually hurt performance, I'll reserve judgement until I see the dynometer tests. However, we might note that the people who complain about their stock muffler's performance hit are often the very same ones who trick out their machines with many pounds of heavy, unaerodynamic, performance-robbing accessories.

They are also the same ones who never once did the slightest hint of performance evaluation, be it dyno time, timed performance events, or whatever. Same chimps that think the noisy vacuum cleaner is doing a better job.

It absolutly does perform better but at what cost?
 

It absolutly does perform better but there is a cost of the added noise. On my race car there are no noise restrictions and most run open headers. On my car I ran some VERY large mufflers which quietened it down a lot with only minimal performance loss.
More air in and out with less restrictions at the right fuel ratio will perform better every time in every way every time.
Now if it is not jetted right for the better air flow it could hurt performance and mileage and it would be as you say just the monkey making the most noise. That is not good for anything or anyone.

I do not want everyone to run open headers or loud pipes I am just stating the fact it can help performance and mileage. Also that I do not want more laws or restrictions. I agree with the AMA stance to pressure the dealers and public to keep them quiet with out making new laws.

The fact that there are plenty of loud motorcycles is part of the reason why I converted one to electric.

http://gallery.me.com/benhdvideoguy/...C06790/web.jpg

This is a photo of it on the dynometer at this summer's Harley 105th Celebration.

The motorcycle clocked in at 12 HP.

Most of the cycles that had been on the dyno were modified to be loud. A person could hear them for miles while revved up on the dynometer.

When I left the event, I just tailed a couple of Harleys for a while. No problem keeping up with them. Not bad for only 12 HP and no gasoline!


Come to think of it, I'm sure the AMA (American MEDICAL Association) must have something to say about hearing protection. They recommend wearing ear muffs while mowing the lawn, but if you do that on a motorcycle, you may miss hearing somebody's horn.

I quieter motorcycle seems safe and friendly to me. I've always liked the sound of the big and quiet Goldwings.

On a quiet bike, you'd hear a car in your blind spot before you accidentally moved over... You'd hear emergency vehicles coming up on you... etc.

This is a great succinct summary of the guiding principle of law.

I got my first bike this year. I have no desire to modify the exhaust. It has a nice sound to it, not too quiet or too obnoxious. Loud pipes are doing serious damage to the sport, I don't want to be part of that.

On the topic of loud exhaust, I put an aftermarket muffler on my Firebird. I did a lot of research first, listened to sound clips, read reviews etc. When it came to sound what I wanted was quality, not quantity. The muffler I went with (Magnaflow) is a little louder than the stock muffler but it's not the loudest exhaust available, or even close. One company actually makes an exhaust system for my car in which the only sound control device of any kind is a "resonator" which is just a hollow cylinder. It's very loud, and not surprisingly sounds like crap. Mine gives a nice deep rumble with no annoying rasp, very mellow at idle and cruise, has a nice roar under hard acceleration. It makes the car much more fun to drive, without being insufferable to those around it. Maybe Harley riders could find a similar happy medium. The problem is that loud pipes are so ingrained in many rider's heads as being part of the culture.

Loud pipes can help save lives
 

Loud pipes can help cars know you are there that is true but they do not need to be obnoxiously loud. Many of the motorcycle riders are using that lame excuse to make them way too loud.
Yes, loud pipes are not good for any of us but can improve effeciency and performance.
They do need to find a happy medium.

As far as I'm concerned, there's no such thing as a "happy medium". The perfect motor would make no sound at all, and real cars & bikes should try to get as close to that as practical engineering & economics will allow.

You have driven V8 powered vehicles before, right? ;)

I mostly agree. Once while out walking, a Goldwing passed by and I'm not kidding, all I heard was the tire noise! :eek: That is impressive. And I like that. On the other hand, the dual exhaust on my '59 Chev (with QUIET mufflers) has a pleasing tone that will NOT offend anyone trying to enjoy their own property or space in peace and quiet, while at the same time not being utterly silent like that Goldwing.

Curly1, I used to live in Manhattan and there was a guy who rode his Harley down 2nd Avenue every day at 6:30 am. Going to work I assume. It was like he TRIED to make as much noise as possible with the revs in each gear. I know he loved the sound of his bike bouncing off the sides of the buildings. You could hear him for miles. The sound reverberated off the buildings like jack hammers. He annoyed maybe 10,000 people a day just so he could have his straight-through Harley exhaust. I'm sure he would have given the "Land of the Free" argument too. But something can also be said for the rest of us having the right to be free from behavior like that.

Not since the '70s, if you discount friends' cars & commercial trucks where I didn't really know what the engine was. Most of my cars have been 4-cylinder, either the standard inline 4 of everything from the Austin-Healey to the '88 Toyota pickup I use for hauling & rough roads now, or the Subaru flat 4. Add in a couple of rotary engined Mazdas, and the current 3-cylinder Insight.

Most of my bikes were fours, too. The one exception that I can remember offhand - a Yamaha twin - I sold after a few weeks because it was too loud.

Another thing about engine noise: I definitely like to be able to hear what the engine is doing when driving a car with a manual transmission, it's easier than watching the tach for shifting and rev matching.

The same thing that compels individuals to power sub-woofers with hundreds of amps :eek:, then "share' their overpowering lack of class. :confused: Notice they never play classical music. :thumbup:

They think perhaps the ladies will swoon and they will score??? I wonder, in the history of Man, if so much as one of those little p****s has managed to attract a female with his booming or fart pipe. :rolleyes:

It kills me how so many people completely miss the purpose of a subwoofer. I have one for my home stereo and one for my car stereo and it is the best thing I have done for either system. But they are completely pointless if not set up correctly. The idea is to fill in the low frequencies that the normal speakers cannot reproduce, so you can hear the music the way it was meant to be heard. Making your trunk rattle is not what they are intended for.

Sorry for de-railing the thread. Again.

I can hear the electric motor in the ForkenSwift, once it gets over about 1000 RPM, roughly (the sound of the brushes and internal shaft fan). But not with the radio on. Oh wait... it has no radio. :)

Driving a quiet vehicle is an unexpected pleasure - one of my favourite things about it. Though I do need to install a bicycle bell for pedestrians in parking lots.

Yeah - and the way it was meant to be heard is INSIDE the car!

Though that's yet another thing that puzzles me about the loud pipes/nice engine sound school. So they get what they think is a "nice" (which usually means louder than stock) sound out of the exhaust, then crank up the stereo until until they drown it out. Seems as sensible as turning up the A/C while leaving the windows rolled down.

I know for a fact that boomers are seriously deluded. They think that what they are "broadcasting" sounds like what they themselves are hearing. Nope, sorry, all I hear from outside the vehicle is THOOOM THOOOM THOOOM THOOOM buzz bzz THOOOM.

I agree, that some engines are just nice to hear. If people just had some common sense it wouldn't be a problem but many people don't.

I am torn on the issue, I have a guy with an uncorked 400 motocrosser 4 stroke that rips by on the trail by my house about once a week, its retarded loud. Somedays I count gears and an impressed he's spinning up the tire in 5th. But if that guy went by several times a day, most days, I would have to ask him to put the stock muffler back on or I'm calling the cops until he gets caught.
Anyways my point is, loud well tuned engines are good to hear in small doses. All the time is too much and I guess we need laws to enforce common sense...
Ian

When I have the stereo on in the Firebird I actually turn it off whenever I have to accelerate, so I can hear the other music. :D

And believe me, from my small exposure to what it really sounds like inside, I'm thankful for that small mercy.