Tony,
Well, if you want to tell people that our events meet DMV noise levels, I
wouldn't go to bat for you. It's apples and oranges. Remember the gent with
the yellow 'Stang mutant? I was working course at GGF and felt nearly
deafened by his car. In fact, Charlie ran out there with a sound meter to
check him.
The SCCA Solo2 Rules:
3.5 MUFFLERS
Adequate mufflers are required for Solo II events. The criterion of
"adequacy" is not what the exhaust system consists of, but the sound
level. Any car deemed by the Event Chairman or his designated
representative to be excessively loud shall not compete without
acceptable modifications installed on the car.
I'm surprised that this is all that is in there, as I was sure that in
previous issues of the Rules there was a set of noise levels. Everyone
measures them differently. Seca has a meter on a fence on one of the uphill
sections. I thought that SCCA had a "method" something like "50 feet from car
as it went by under racing conditions". While the State's version, that SAE
method, is something like measure 1 meter from the exhaust, 45 degrees from
the outlet direction, with the engine at 66 percent of maximum RPM (don't
quote me on that) but not under load. Given that the State allows 95 decibels
under that situation and sound generally drops 3 dB each time the distance
doubles, that can still be fairly loud. But we also allow cars that are no
longer street legal to run at the events, such as the yellow 'Stang. Bottom
line is we have to avoid complaints as well.
Good luck on your research! Paul T.
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