Originally Posted by DMcBrideBoston
Awesome Idea, he did not use a Db meter. I will stop back by on Monday and report back.
Have you talked to the shop yet?
Edit: I found the relevant section. HERE
The questions to ask are:
The Massachusetts Registry of Motor Vehicles
540 CMR 4.00
4.04 Procedures for Inspection of Non-Commercial Motor Vehicles (continued)
(5) Muffler and Exhaust System. Accelerate motor to test for prevention of unnecessary noise and emission of any unreasonable amount of smoke. The exhaust system, exhaust manifold(s), exhaust pipe(s), muffler(s), and tailpipe(s), if designed to be so equipped, shall be tight and free of leaks. System components shall be securely fastened with fasteners in place and undamaged. All motor vehicle exhaust systems shall discharge the exhaust beyond operator, passenger, and/or trunk compartment. Unnecessary noise is herein defined as any noise which is louder than that emitted by the vehicle when equipped with the original manufacturer's equipment. A gas or diesel vehicle will be rejected if, at normal operating temperature, at any constant speed over 15 MPH, (approximately 1,000 to 1,200 RPM's) visible black or blue exhaust emissions are evident.
How do they define the baseline "noise" rating for any given make and model, as all makes and models are different; and how do they compare the "original manufacturer's equipment" exhaust noise to the "Current" exhaust noise? How are the measurements taken? Interior or Exterior? What are the reference dB levels that must be met?
The only sound levels I can find for the Thunderbird are interior measurements from Car & Driver, October 1993 on a brand new 4.6L, 1994 Thunderbird HERE
Recorded at the following levels:
Idle: 43 dBA
Full Throttle Acceleration: 77 dBA
70-MPH Crusing: 67 dBA
70-MPH Coasting: 67 dBA
Db meter anyone? Ultimately, I guess what the state is saying is that any exhaust other than stock is unacceptable. What a crock-o-crap. Just tell them it's an OEM Harley-Davidson special edition car. I never could understand why states give cars so much crap about their exhausts and don't say anything about how loud some motorcycles are.
I hope this helps.
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