Does GM claim any noise level on stock exhaust?
08-27-2010, 10:04 PM
#6
Well, some SLP SS's had LM1's on them. Those are pretty loud and since GM farmed the cars out to SLP, I'd assume that could be considered stock since it came off the dealership floor like that.
That is the excuse I use with local law enforcement anyway and I still have the papers for my SS that have the lm1 option on them. I found with a lot of instances though, it just depends on location and the cop. I'm in rural Iowa and even with a full 3" set-up and TD's, my car isn't near as loud as some of the trucks out here.
So just say yes, and give them the SLP LM1 information.
That is the excuse I use with local law enforcement anyway and I still have the papers for my SS that have the lm1 option on them. I found with a lot of instances though, it just depends on location and the cop. I'm in rural Iowa and even with a full 3" set-up and TD's, my car isn't near as loud as some of the trucks out here.
So just say yes, and give them the SLP LM1 information.
08-27-2010, 10:06 PM
#7
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Doesn't matter, if someone can hear it, then it's disturbing the peace. Period. Your MOTOR reving with dead silent exhaust could be considered illegal. Thats the problem with creating so many laws that they become in fact, rediculous.
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08-27-2010, 10:53 PM
#8
Well, some SLP SS's had LM1's on them. Those are pretty loud and since GM farmed the cars out to SLP, I'd assume that could be considered stock since it came off the dealership floor like that.
That is the excuse I use with local law enforcement anyway and I still have the papers for my SS that have the lm1 option on them. I found with a lot of instances though, it just depends on location and the cop. I'm in rural Iowa and even with a full 3" set-up and TD's, my car isn't near as loud as some of the trucks out here.
So just say yes, and give them the SLP LM1 information.
That is the excuse I use with local law enforcement anyway and I still have the papers for my SS that have the lm1 option on them. I found with a lot of instances though, it just depends on location and the cop. I'm in rural Iowa and even with a full 3" set-up and TD's, my car isn't near as loud as some of the trucks out here.
So just say yes, and give them the SLP LM1 information.
SSs came with loudmouths stock?
08-30-2010, 03:21 AM
#11
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Couldn't find the stock level but I found this off a z28 forum. Not sure if it helps or not. I'm sure the stock exhaust is lower than all of these. Not sure what car these tests were done on but I'm sure it wasn't stock.
Sound Off in Quietest to Loudest (Decibels):
1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).
Sound Off in Quietest to Loudest (Decibels):
1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).
))
08-31-2010, 08:19 PM
#13
GM Performance Parts Exhaust Systems FAQS
Q. Is this system louder then factory? And is it loud enough that a cop would pull me over for it?
A. The cat-back exhaust system meets the 95daA noise limit imposed by some states on exhaust-system modifications, as measured by SAE J1169.
Some states and local jurisdictions impose more stringent requirementes. Be sure to check whether this aftermarket installation meets the noise limits where you will register and drive your vehicle.
ALSO:
The Sema Action
The SEMA Action Network
The Specialty Equipment Market Association (SEMA) isn't just an organization that puts on a huge trade show in Sin City every year. Many readers probably also know that it is dedicated to lobbying against legislation that will harm the hobby, as well as supporting legislation that will foster it. And SEMA has come up with a great way to keep us informed of issues that enthusiasts may need to get involved in: it's called the SEMA Action Network, or SAN. Its purpose is to disseminate information and to rally support of enthusiasts, car clubs, and members of the auto parts industry, amplifying the overall voice of SEMA to the benefit of all.
Indeed, SEMA's SAN had a hand in getting several of the laws you see quoted in this story series passed, where more restrictive laws had been pending. It is able to accomplish this by providing lawmakers with model language that replaces vague and subjective provisions with fair and enforceable standards. One example would be the SEMA model legislation that establishes an exhaust noise-testing standard based on SAE J1169. Under this model, vehicles are certified to be in compliance with the law if during the test, the highest recorded decibel level is under 95 decibels (using the dBA, or "A-weighted" decibels, standard). This is done with a sound meter placed at a specific orientation 20 inches from the exhaust outlet, the car stationary and in neutral, and the engine operating in a steady-state condition of 3/4 maximum rated engine speed. "While this does not take away from law enforcement's ability to cite for loud exhaust systems, it does allow individuals a method of proving that their vehicles meet the 95 decibel standard," says SAN director Jason Tolleson.
Q. Is this system louder then factory? And is it loud enough that a cop would pull me over for it?
A. The cat-back exhaust system meets the 95daA noise limit imposed by some states on exhaust-system modifications, as measured by SAE J1169.
Some states and local jurisdictions impose more stringent requirementes. Be sure to check whether this aftermarket installation meets the noise limits where you will register and drive your vehicle.
ALSO:
The Sema Action
The SEMA Action Network
The Specialty Equipment Market Association (SEMA) isn't just an organization that puts on a huge trade show in Sin City every year. Many readers probably also know that it is dedicated to lobbying against legislation that will harm the hobby, as well as supporting legislation that will foster it. And SEMA has come up with a great way to keep us informed of issues that enthusiasts may need to get involved in: it's called the SEMA Action Network, or SAN. Its purpose is to disseminate information and to rally support of enthusiasts, car clubs, and members of the auto parts industry, amplifying the overall voice of SEMA to the benefit of all.
Indeed, SEMA's SAN had a hand in getting several of the laws you see quoted in this story series passed, where more restrictive laws had been pending. It is able to accomplish this by providing lawmakers with model language that replaces vague and subjective provisions with fair and enforceable standards. One example would be the SEMA model legislation that establishes an exhaust noise-testing standard based on SAE J1169. Under this model, vehicles are certified to be in compliance with the law if during the test, the highest recorded decibel level is under 95 decibels (using the dBA, or "A-weighted" decibels, standard). This is done with a sound meter placed at a specific orientation 20 inches from the exhaust outlet, the car stationary and in neutral, and the engine operating in a steady-state condition of 3/4 maximum rated engine speed. "While this does not take away from law enforcement's ability to cite for loud exhaust systems, it does allow individuals a method of proving that their vehicles meet the 95 decibel standard," says SAN director Jason Tolleson.
Last edited by mean_greenZ; 08-31-2010 at 08:29 PM.
04-11-2012, 05:01 PM
#19
TECH Senior Member
The best I can find is interior noise levels from comparison tests:
http://www.stangbangers.com/99GT_vs_...8_Article1.htm
http://www.stangbangers.com/96_Cobra...rd_Article.htm
Don't know if that will help at all...
I think your best bet will be to rework your exhaust a little, get a cutout for when you want more noise and power, and add an extra resonator or small/bullet muffler along with whatever else you have.
http://www.stangbangers.com/99GT_vs_...8_Article1.htm
http://www.stangbangers.com/96_Cobra...rd_Article.htm
Don't know if that will help at all...
I think your best bet will be to rework your exhaust a little, get a cutout for when you want more noise and power, and add an extra resonator or small/bullet muffler along with whatever else you have.
04-11-2012, 08:10 PM
#20
My point was to measure your car and make changes until you get what you need. If its failing now, youre gonna have to change something. If they say you have to be 85 or less, then you gotta change it up, at least just to get tested. What exactly is your exhaust setup? I dont see it listed anywhere...