Exhaust choices with 92 dB noise limit

[jmabarone]

Hey guys, I was wondering if you had any advice on exhaust choices to make power within a strict limit. I believe the car has a complete Racing Beat exhaust including header, so I'd like to keep it if possible. I don't really have any way to check the car as it sits (not street legal) and no sound meter.

Here is the excerpt from the specific rules:

"Noise Limit: ChumpCar’s basic noise limit FOR ALL EVENTS is 92dB @ 50
feet from the track. Certain events may impose a tighter noise restriction – check all event supplemental rules. Excessive noise will result in a black-flag and required repairs prior to being re-admitted to the race. A second offense will result in disqualification and removal from the event.
9.13.1. Attention Rotary Teams – 92db. Everyone repeat after me..."

Thanks!
Jake

[TOOL]

Big presilencers was what they used to do in the 90s, along with the biggest silencer you could fit in the back. I'm talking truck sized.
Power was up and noise was down.

The other trick was to have an extra muffler on the back, stuck on the end of your main one to get the noise down. Cheap and cheerful. A lot of guys in 70s and 80s used to have external muffler running under the rear bumper east/west.

[spirit r]

I hope these helps:
Thomas


Exhaust Sound Level Compliance

Does my exhaust system comply with the law?

All Racing Beat "cat-back" exhaust systems and/or replacement mufflers intended for street use are designed to comply with the California imposed 95-db limit under Society of Automotive Engineers (SAE) test procedure J1169.

However, the addition of performance catalytic converters, headers, presilencers, etc... may impact the sound level of the exhaust system and should be taken into consideration when evaluating the sound levels and tonal quality of a specific exhaust system.

What do I do if I've received a ticket for a "modified exhaust" in California?

Thanks to a SEMA-sponsored law, California automobile hobbyists are now better equipped to fight unfair exhaust noise citations issued by state law enforcement officers. Legislation signed into law in 2002 provides for a statewide exhaust noise testing program that will allow motorists to prove they comply with state noise standards.

The law requires smog check stations that provide referee functions to perform the test. These Referee Stations will issue certificates of compliance for vehicles when tests of their exhaust systems demonstrate that they emit no more than 95-decibels, under Society of Automotive Engineers (SAE) test procedure J1169. Only those vehicles that have received a citation for an exhaust noise violation will be permitted to submit their vehicle for the test. Contact a Referee Station to schedule an appointment.

The law also allows courts to dismiss citations for exhaust systems that have been tested and for which a certificate of compliance has been issued. Fees charged to motorists for the certificates of compliance will pay for the testing program.

"The law forces compliance with an objectively measured standard in a fair and predictable test. Through this procedure, motorists who drive vehicles legally equipped with modified exhaust systems can confirm that they comply with California's exhaust noise standards," said SEMA Director of Government Affairs Steve McDonald. "For years, the enforcement policy used by police officers deemed nearly all exhaust system modifications illegal, even where the noise levels were not excessive or unusual. That policy left exhaust system manufacturers, dealers and their customers without recourse."

In 2001 a prior SEMA-sponsored bill was signed into law that compelled law enforcement officials to tie exhaust system noise citations to the 95-decibel limit and to make clear that aftermarket modified exhaust systems are legal if they comply with the standard. However, exhaust noise citations were still primarily prosecuted solely based on the officer's subjective judgment. This newer law should go far toward improving motorists' odds of beating the ticket in court.

"Motorists who modify their vehicles for durability, appearance and performance prefer aftermarket exhaust systems," McDonald added. "By establishing this evenhanded testing process, this law will serve to benefit consumers who favor these state-of-the-art products, the aftermarket industry which markets them and even police officers who are charged with enforcing the law."

Important Note: Exhaust sound level laws vary from state-to-state and are constantly changing. We suggest you contact your local and state authorities for laws and requirements for your specific application. Use this guide as reference only.