Illegal Exhaust Part 2: The POPO is back, and dumber than ever.
Aug 19, 2004, 07:38 PM
#31
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[QUOTE=rburris28]
This is 1-2 A-weighted decibels, which means it is even less than the standard dB weighting. As you know, the human ear is less sensitive to lower frequency sounds (such as an exhaust sound.. especially if it is just rumbling at idle).
Just so you know, a human ear cannot really differentiate between 1-2 decibels (unless you've been trained?). In fact, the human ear perceives a 10dB difference as being twice as loud.
End of physics lesson 2.
PS. mods, can you please not move this to the regional forums? those forums are pretty much dead, and with the thread here and I can get more feedback. Thanks!
Originally Posted by zstryder
After Chris said he'd do it to his exhaust, I've been thinking about doing that for awhile. I'm not exactly a good painter, though. Can I simply just slap on a layer of high temp black paint? Or do I need to prep the surface with something beforehand?
Anyway, when I got pulled over the first time, Chris and I went around at a meet using a decibel meter to measure exhaust volumes. My silenced JIC was literally 1-2dB over stock. As the officer read the law to me, he says any aftermarket exhaust louder than factory is illegal. So apparently as long as I can prove that this is "factory exhaust" volume then I'm off the hook. [END QUOTE]
I feel it my duty to point out that 3 dB louder is twice as loud; ie., 93 dB is twice as loud to the human ear as 90 dB.
End of physics lesson.
Anyway, when I got pulled over the first time, Chris and I went around at a meet using a decibel meter to measure exhaust volumes. My silenced JIC was literally 1-2dB over stock. As the officer read the law to me, he says any aftermarket exhaust louder than factory is illegal. So apparently as long as I can prove that this is "factory exhaust" volume then I'm off the hook. [END QUOTE]
I feel it my duty to point out that 3 dB louder is twice as loud; ie., 93 dB is twice as loud to the human ear as 90 dB.
End of physics lesson.
This is 1-2 A-weighted decibels, which means it is even less than the standard dB weighting. As you know, the human ear is less sensitive to lower frequency sounds (such as an exhaust sound.. especially if it is just rumbling at idle).
Just so you know, a human ear cannot really differentiate between 1-2 decibels (unless you've been trained?). In fact, the human ear perceives a 10dB difference as being twice as loud.
End of physics lesson 2.
PS. mods, can you please not move this to the regional forums? those forums are pretty much dead, and with the thread here and I can get more feedback. Thanks!
Aug 19, 2004, 07:47 PM
#32
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I got bagged in Springfield 10 minutes after I installed my BR turbo back system with the Magnaflow muffler. The muffler was still nice and shiney. The next day I bought a can of Bar-B-Que black hi-temp spray paint and painted the muffler. Cops don't even look twice now. It probably helps too that I have the low wing.
Aug 19, 2004, 08:05 PM
#33
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[QUOTE=zstryder]This is 1-2 A-weighted decibels, which means it is even less than the standard dB weighting. As you know, the human ear is less sensitive to lower frequency sounds (such as an exhaust sound.. especially if it is just rumbling at idle).
Just so you know, a human ear cannot really differentiate between 1-2 decibels (unless you've been trained?). In fact, the human ear perceives a 10dB difference as being twice as loud.
End of physics lesson 2. [END QUOTE]
I beg to differ- but then I only have a minor in physics.
From http://www.phys.unsw.edu.au/~jw/dB.html
The difference in decibels between the two is defined to be
10 log (P2/P1) dB ****** where the log is to base 10.
If the second produces twice as much power than the first, the difference in dB is
10 log (P2/P1) = 10 log 2 = 3 dB.
The dBA weighted scale is designed to more closely mimic the human ear. It is true that 1 dB difference is difficult to distinguish, but since it is a logarithmic scale, 3 dB is much louder. Most of the irritating sounds that Mr. Policeman heard are in the 1000 to 4000 Hz range that the dBA scale is designed for.
I wasn't trying to belittle your point or argue against you. I was just trying to inject a little knowledge into the forum. I didn't want someone else reading this discussion and thinking it would take a 186 dB muffle to sound louder than a 93.
End of physics lession 3.
(P.S.- please challenge me on more wonderful physics questions- I love reading about the stuff)
Just so you know, a human ear cannot really differentiate between 1-2 decibels (unless you've been trained?). In fact, the human ear perceives a 10dB difference as being twice as loud.
End of physics lesson 2. [END QUOTE]
I beg to differ- but then I only have a minor in physics.
From http://www.phys.unsw.edu.au/~jw/dB.html
The difference in decibels between the two is defined to be
10 log (P2/P1) dB ****** where the log is to base 10.
If the second produces twice as much power than the first, the difference in dB is
10 log (P2/P1) = 10 log 2 = 3 dB.
The dBA weighted scale is designed to more closely mimic the human ear. It is true that 1 dB difference is difficult to distinguish, but since it is a logarithmic scale, 3 dB is much louder. Most of the irritating sounds that Mr. Policeman heard are in the 1000 to 4000 Hz range that the dBA scale is designed for.
I wasn't trying to belittle your point or argue against you. I was just trying to inject a little knowledge into the forum. I didn't want someone else reading this discussion and thinking it would take a 186 dB muffle to sound louder than a 93.
End of physics lession 3.
(P.S.- please challenge me on more wonderful physics questions- I love reading about the stuff)
Aug 19, 2004, 08:15 PM
#34
Some "asshat" of a cop tried the same thing on me...but my exhaust actually was stock. So I told him if he ever profiles me again, (also accused me of speeding when I knew I wasnt) I would take him to court and sew. I've had no troubles since...though the whole squad is probably out to get me now. 
Aug 19, 2004, 08:26 PM
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It has been my experience in the past going to court that if you are trying to fight a ticket, proving that others are also illegal will serve no purpose. the only agenda before the judge is that your car is illegal. it is irrelavent what other cars db at, just that yours is illegal. if you are 1-2 db above stock, the bottom line is that you are above stock, not that a harley is 10db over yours, etc...
anyone have better luck at fighting this?
anyone have better luck at fighting this?
Aug 19, 2004, 08:28 PM
#36
That physics fool is correct 
The dB scale is a logarithmic one. 3 dB is twice as loud to the human ear.
zstryder is also correct in that the dBA scale is more tuned to the level of hearing acuity in humans; we don't perceive changes in low and high frequencies as well.
But the letter of the law says that even if it's 1 dB louder, it's a violation.
The dB scale is a logarithmic one. 3 dB is twice as loud to the human ear.zstryder is also correct in that the dBA scale is more tuned to the level of hearing acuity in humans; we don't perceive changes in low and high frequencies as well.
But the letter of the law says that even if it's 1 dB louder, it's a violation.
Aug 19, 2004, 09:13 PM
#37
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Physics shmysics. I'm an engineer though, so what do I know? I agree, I do enjoy banter about this sort of stuff. But for those actually interested in what a difference of 3dB sounds like, please click the link rburris provided. There's a little app there that replays some static in decrementing levels of 3dB and 1dB. You'll notice that the difference for 3dB is barely noticeable, and the difference of 1dB is not even noticeable.
Back on topic though, the cop thinks I have a stock exhaust. He thinks the factory exhaust is illegal - and that something was wrong with the car itself (so even OE is now illegal). So it's not an issue of saying "oh my exhaust was only 1 dB louder than stock," but rather that I simply prove to the judge that my exhaust is the factory exhaust. If that is done, then the case is out the window. Additionally, the cop's simple deduction of what was "loud" already lends credibility to my case. No? Or am I simply out of my mind?
But for those actually interested in what a difference of 3dB sounds like, please click the link rburris provided. There's a little app there that replays some static in decrementing levels of 3dB and 1dB. You'll notice that the difference for 3dB is barely noticeable, and the difference of 1dB is not even noticeable. Back on topic though, the cop thinks I have a stock exhaust. He thinks the factory exhaust is illegal - and that something was wrong with the car itself (so even OE is now illegal). So it's not an issue of saying "oh my exhaust was only 1 dB louder than stock," but rather that I simply prove to the judge that my exhaust is the factory exhaust. If that is done, then the case is out the window. Additionally, the cop's simple deduction of what was "loud" already lends credibility to my case. No? Or am I simply out of my mind?
Aug 19, 2004, 09:20 PM
#38
Stoopid FHP: Long Rant
How about this story. I used to own an Integra Type R. That thing was a cop magnet. Anyway, I was driving down the 417 in Orlando. I had just got on and was nearing a bend in the hwy that I knew was a favorite spot for the FL HWY Patrol. I'm cruising along on the right lane with the flow of traffic which is about 5 mph over the speed limit. i look in the rear view mirror and a light colored car approaching fast. Soon he's upon me and passes me on the left lane and I notice that the car has a metallic pearl sort of paint job. I remember thinking to myself, "that guy better slow down."
This car is still in view when I see his brake lights suddenly come on. That could only mean one thing, 'cause there wasn't any vehicle in front of him. In the next instant I see flashing lights in the median. It's a hwy patrol cruiser trying to make a u-turn so it can merge with the southbound traffic. I think to myself that somebody was gonna get a ticket. So I keep looking in the rear view mirror to see the flashing lights, and I wait, and wait. No lights. Meanwhile the speeder had vanished from sight. I'm expecting to catch sight of him as I get to the top of the overpass , but as I reach that point on the road I still can't see him among the vehicles up ahead. We'll that one got away. Now I look in the rear view and see the poopoo. You're too late man.
He hesitates for a split second , slows down beside me and turns on his siren.
S... he he's got me. All this time I had been in the right lane going with the flow.
Oh nuts, he's tagged me for going over the speed limit (about 75) Did you know you were going around 90 he says. This is when I start thinking that he thinks I'm the other guy. Well you've added the big wing to your car so it must be you cuz the car I saw had a big wing. Whoah this guy didn't even know that Type R's come with the wing. But what you saw was a Honda officer, I'm driving an Acura. So he starts getting defensive and says he knows the difference bet. a Honda and an Acura. NOT. To make a long story short he thinks it was me because he saw a light colored car with a wing. I tried to tell him that it wasn't me because what he had seen was a pearl colored Honda prelude with an aftermarket wing. Nothing I could say would change his mind. Sorry for the rant but I've been wanting to get this off my chest for a while.
BTW that's one of the reasons I now own an 04 RS.
This car is still in view when I see his brake lights suddenly come on. That could only mean one thing, 'cause there wasn't any vehicle in front of him. In the next instant I see flashing lights in the median. It's a hwy patrol cruiser trying to make a u-turn so it can merge with the southbound traffic. I think to myself that somebody was gonna get a ticket. So I keep looking in the rear view mirror to see the flashing lights, and I wait, and wait. No lights. Meanwhile the speeder had vanished from sight. I'm expecting to catch sight of him as I get to the top of the overpass , but as I reach that point on the road I still can't see him among the vehicles up ahead. We'll that one got away. Now I look in the rear view and see the poopoo. You're too late man.
He hesitates for a split second , slows down beside me and turns on his siren.
S... he he's got me. All this time I had been in the right lane going with the flow.
Oh nuts, he's tagged me for going over the speed limit (about 75) Did you know you were going around 90 he says. This is when I start thinking that he thinks I'm the other guy. Well you've added the big wing to your car so it must be you cuz the car I saw had a big wing. Whoah this guy didn't even know that Type R's come with the wing. But what you saw was a Honda officer, I'm driving an Acura. So he starts getting defensive and says he knows the difference bet. a Honda and an Acura. NOT. To make a long story short he thinks it was me because he saw a light colored car with a wing. I tried to tell him that it wasn't me because what he had seen was a pearl colored Honda prelude with an aftermarket wing. Nothing I could say would change his mind. Sorry for the rant but I've been wanting to get this off my chest for a while.
BTW that's one of the reasons I now own an 04 RS.
Last edited by 04rs; Aug 19, 2004 at 09:24 PM.
Aug 19, 2004, 09:25 PM
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If you don't like the law, work on having it changed. SEMA has be successful in California and in Washington in having the state law (similar to the Idaho and Virginia laws described above) changed to the Federal law that references the SAE standard of 95 dB. This changes the law from "the cop thinks your exhaust is too loud" to a measurable, quantifiable number.
Check out http://www.semasan.com/ for more details.
I got pulled over in my old GVR-4 (3" ending in twin SuperTrapp's) a couple of times, but since the law has changed the cops don't even look at me twice. Although I'll admit the 3" Magnaflow combo on the EVO is quite a bit quieter than the GVR-4.
Mark
Check out http://www.semasan.com/ for more details.
I got pulled over in my old GVR-4 (3" ending in twin SuperTrapp's) a couple of times, but since the law has changed the cops don't even look at me twice. Although I'll admit the 3" Magnaflow combo on the EVO is quite a bit quieter than the GVR-4.
Mark
Aug 19, 2004, 09:48 PM
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I have looked into this in idaho, and the issue is not coming up with a definitive db number for noise, but that any modifications from factory are illegal. not much to work with there. I have been pulled over 1/2 dozen times for exhaust issues and it's never that I am too loud, it's that it is not the stock exhaust that came fitted on the car.(was on my old eclipse gst with 3" and an apexi dunk) the cops here use it more to look for other issues, drugs, drinking, insurance, etc.....not many tickets given unless you push the issue.
would love to see the same law that cali has, but don't think that the lawmakers will ever change. most of them who own custom cars are driving classics with maybe headers and glasspacks, but the cops leave them alone. it's all about pulling over imports..
now if only we could get all the lawmakers to buy modded evo's........
would love to see the same law that cali has, but don't think that the lawmakers will ever change. most of them who own custom cars are driving classics with maybe headers and glasspacks, but the cops leave them alone. it's all about pulling over imports..
now if only we could get all the lawmakers to buy modded evo's........
Aug 20, 2004, 06:56 AM
#42
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It's not a moving violation, so no, no points. But still, I don't want to have to pay a recurring $80 fee for simply owning my exhaust. Do you know what I mean?
Aug 20, 2004, 07:13 AM
#43
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Why I love living at the bottom of texas, straight piped evo 
, and here cops profile the ricers because they're morons, peeling out everywhere and just being asses.
, and here cops profile the ricers because they're morons, peeling out everywhere and just being asses.
Aug 20, 2004, 07:20 AM
#44
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State of MA opinion. PIA but take it to court. The people will have to test weather or not you're in violation of the decible/polution violation. This will consist of an expensive test and a waste of time on the states part. Amongst a bunch of fairly clear cut cases involving speeding and stop sign violations, the judge will most likely dismiss on the spot. My rule of thumb, even if your dead guilty of a traffic violation take it to court. The majistrate will cut in half, but 9 times out of ten, the judge will dismiss apon hearing.
Originally Posted by zstryder
<History>
For those that don't know, I got pulled over earlier this year for having an aftermarket exhaust (JIC). I have since popped in the silencer, which makes it just about stock loud. </History>
So I'm comin' home from work on the freeway and pass by a stationery cop. Mind you, I'm in the far left lane, he's in the far right shoulder (4 lanes over). I pass by him, 30 seconds later, I can see him in my rearview mirror. He's clearly speeding (100+) to catch up to me. He catches up, pulls up to the lane to the right of me, and hangs out for about 15 seconds. Then the blue lights go off.
He tells me I've got an improper exhaust system. Bingo. Nothing new here. I talk to him for a bit, and somehow I've convinced him that my exhaust system is stock. He still thinks it's too loud, even though it was a stock exhaust, so he gives me a ticket anyway... hmm, what now? I proceed to ask him by what merit he decided that my exhaust was too loud. He says:
"Well, when I stand behind my car, you can't hear it."
"When I stand behind your car, I can hear your exhaust. Therefore it's illegal."
HAHA. I don't think I've heard anything more inane. But he surprises me again. "My engine is bigger than yours, but yours is louder than mine. There is no reason that that should happen." He says that my car obviously came with a high performance exhaust from the factory, which is illegal. I tell him that my car is a high performance vehicle, that it is not a normal Lancer, that it comes with 280hp from the factory, thus, it is only normal for it to come equipped with a high performance exhaust. He says in a condescending tone "I'm not impressed. Your car is too loud." Hm, right, like you can't hear a Cobra exhaust at idle.
It was clear this guy was out to get me as soon as I passed by him. If it was because my car was bright blue, or because I had a huge wing on it, one of the two obviously set him off. He couldn't have seen nor heard my exhaust from where he was standing by, especially with the amount of traffic on the freeway.
So now I got a court date to attend. Last time I paid my ticket off because I figured once I put in my silencer, this wouldn't happen again. After all, with the silencer in, the car's idle and WOT volume is only 1db louder than stock. Guess I was wrong. This time though, I'm going to fight. If the guy thinks this is a stock exhaust, and given the reasons he believed my exhaust to be too loud, his reasoning is far too subjective and should easily crumble in court. Unless of course, my judge is a complete asshat. In that case, you guys will see me *****ing about this in October.
For those that don't know, I got pulled over earlier this year for having an aftermarket exhaust (JIC). I have since popped in the silencer, which makes it just about stock loud. </History>
So I'm comin' home from work on the freeway and pass by a stationery cop. Mind you, I'm in the far left lane, he's in the far right shoulder (4 lanes over). I pass by him, 30 seconds later, I can see him in my rearview mirror. He's clearly speeding (100+) to catch up to me. He catches up, pulls up to the lane to the right of me, and hangs out for about 15 seconds. Then the blue lights go off.
He tells me I've got an improper exhaust system. Bingo. Nothing new here. I talk to him for a bit, and somehow I've convinced him that my exhaust system is stock. He still thinks it's too loud, even though it was a stock exhaust, so he gives me a ticket anyway... hmm, what now? I proceed to ask him by what merit he decided that my exhaust was too loud. He says:
"Well, when I stand behind my car, you can't hear it."
"When I stand behind your car, I can hear your exhaust. Therefore it's illegal."
HAHA. I don't think I've heard anything more inane. But he surprises me again. "My engine is bigger than yours, but yours is louder than mine. There is no reason that that should happen." He says that my car obviously came with a high performance exhaust from the factory, which is illegal. I tell him that my car is a high performance vehicle, that it is not a normal Lancer, that it comes with 280hp from the factory, thus, it is only normal for it to come equipped with a high performance exhaust. He says in a condescending tone "I'm not impressed. Your car is too loud." Hm, right, like you can't hear a Cobra exhaust at idle.
It was clear this guy was out to get me as soon as I passed by him. If it was because my car was bright blue, or because I had a huge wing on it, one of the two obviously set him off. He couldn't have seen nor heard my exhaust from where he was standing by, especially with the amount of traffic on the freeway.
So now I got a court date to attend. Last time I paid my ticket off because I figured once I put in my silencer, this wouldn't happen again. After all, with the silencer in, the car's idle and WOT volume is only 1db louder than stock. Guess I was wrong. This time though, I'm going to fight. If the guy thinks this is a stock exhaust, and given the reasons he believed my exhaust to be too loud, his reasoning is far too subjective and should easily crumble in court. Unless of course, my judge is a complete asshat. In that case, you guys will see me *****ing about this in October.
Aug 20, 2004, 07:31 AM
#45
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PS, I used to have a 00 audi s4, and was once pulled over for a busted taillight. Infact, it was the bright single sided rear fog lamp incorporated with the normal taillights. This is operated by a switch and can be turned on and off. Even when I stood outside the car and toggled the switch, the cop insisted that I fix my light. Whatever.
Originally Posted by ducaticorse
State of MA opinion. PIA but take it to court. The people will have to test weather or not you're in violation of the decible/polution violation. This will consist of an expensive test and a waste of time on the states part. Amongst a bunch of fairly clear cut cases involving speeding and stop sign violations, the judge will most likely dismiss on the spot. My rule of thumb, even if your dead guilty of a traffic violation take it to court. The majistrate will cut in half, but 9 times out of ten, the judge will dismiss apon hearing.