AMA on noise

[dichotomous]

Originally Posted by adam728

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

[MazdaMatt]

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)

[Curly1]

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.

[jamesqf]

Originally Posted by Curly1

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.

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.

[Curly1]

Originally Posted by jamesqf

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.

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.

[basjoos]

Originally Posted by Frank Lee

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

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.

[adam728]

Originally Posted by dichotomous

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.

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.

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.

[jamesqf]

Originally Posted by basjoos

Anyway, whenever I see some guy sitting in his modified-to-be-noisier ride, the image of that chimp comes to mind.

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.

[Frank Lee]

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.

[Curly1]

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.