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      07-16-2011, 11:15 PM   #2
Dee Pee
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Drives: '02 M Roadster, '11 AW 1M
Join Date: Jun 2011
Location: Portland, OR

iTrader: (0)

From the CHP vehicle code:

Section 1030-1036, 13 CCR, were intended to be used by Licensed Muffler Certification Stations as a means of detection if an exhaust system met the requirements of the Muffler Certification Program (When those programs were operational) They specify testing procedures for motor vehicle exhaust noise alone (as opposed to total vehicle noise) This procedure specifies a limit of 95 dB measured 20 inches from the exhaust pipe outlet with the engine operating in neutral, typically at speed of 3000-5000 rpm. It applies only to passenger vehicles. It does not apply to motorcycles or to vehicles over 6000 pounds gross weight.

I'm guessing that will be the case for Canadian as well as all US vehicles as CA has the strictest regulations. In order to sell the 1M, the car has to conform to those standards. BUT, in an earlier section, they state that under full accelaration, 50 feet from the car, that the acceptable dba should be 80.

I have a decibel meter and can check it for you but my car doesn't arrive until 8/30 at the earliest.