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PostPosted: November 9, 2016, 9:23 pm 
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Joined: December 4, 2011, 6:19 pm
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Hi folks,

I'm currently working on a project that will have a sports car race track as part of a new development. The development will be fairly close to an existing residential area so we're considering a decibel limit at the track. For comparative purposes, if you have been at a track that has a decibel limit can you tell me;

1. what track or facility this applies to
2. what the decibel limit/standard is
3. how is it measured (example; behind the exhaust, beside the exhaust, 10' from the exhaust, 1' from the exhaust, engine at idle, engine at full revs, engine at 3000 rpm, etc)
4. In your opinion how restrictive is the sound limit, how hard is it to achieve it?

Any other thoughts that you have on this topic would be welcome too. Thanks very much for your input.

Bill

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PostPosted: November 9, 2016, 9:41 pm 
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Hi Bill-
The tracks that I know about that use sound limits have the limits monitored by SCCA. The SCCA rules have the sound measured at a set point around the track, 50 feet from the edge of the track. They typically pick a spot where cars are at near full throttle when they go by. IIRC the limit at Roebling Road in Savannah is 103 dB. Others vary, and I don't remember them enough to quote a number.

:cheers:
JDK

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PostPosted: November 9, 2016, 11:42 pm 
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Location: White Rock, BC, Canada
Laguna Seca is known for it's low dB limit at 90, 92, 103 (at 50ft?) depending on days. 90/92 is REALLY low. I autoX with a similar level and a lot of cars/bikes have a hard time complying. Most stock vehicles are OK, but many are not. Tire squeal is also a concern if you are planning other events (drifting, autoX etc). We run at an airport which is federally regulated. Problem is the laws do not specifically allow car noise; only aircraft. We've had to be very careful to keep our autoX pad because of that.

Pacific Raceways also has sound limits, but I think they only regulate times (9-5pm most days). Think they run top fuel there so I can't imagine dB limits exist then. There are houses pretty close to the track so I'd bet they have dealt with noise complaints before.

The biggest thing is to make bloody sure you know what the by-laws of the region you are in are, and talk with the people in charge prior. Find out what noise, and when, is allowed and reasonable. I've read some city bylaws which basically say " anyone being annoying at anytime is not allowed". That's all it takes to ruin you. You must, MUST have the bylaws and politicians on your side or all it takes is one whiner to shut you down. Honestly, I would think very hard about an area that already has many residents nearby.

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PostPosted: November 10, 2016, 12:06 am 
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I couldn't tell you HOW they measure them, only that most tracks I've been on have 95 db limit.

I think I've only been on one that had 100 db limit and that was loud enough to hurt your ears

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PostPosted: November 10, 2016, 8:12 am 
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As mentioned, Laguna Seca should be your benchmark. I can't imagine a track being able to function with any lower sound level than they have. $7K/day for a 90db limit, $15K/day for 92db and something like $26K for 103db. Also, there are an extremely limited number of 92 and 103 days. Their sound level is dictated and monitored by the county (who owns the track, odd situation).

At 90db we can't test development Corvettes and Camaros in stock form at Laguna. We either need to short shift TWO gears up (in 5th where 3rd would be appropriate) or put on test mufflers that are massively quieter than stock.

Another couple footnotes: 90db isn't 90db everywhere. A local track here in MI has a 90db limit that's pretty easy to pass. It's booth is inside the track in a swampy area. Laguna's is outside the track against a big, rocky hillside. Also, equipment and settings used make a huge difference. Weather makes a big difference, both temp and humididity. It's not easy to get consistent numbers. Politicians DO NOT understand the physics of changing sound measurements/effectiveness.

All that said, I agree that building near people is just a recipe for a bad time. We've been testing at our GM proving grounds since 1934 when it was in the middle of nowhere and many new neighbors complain after they've build a house near the track. Some have been successful in getting testing restrictions. We are very well liked by local politicians, we only make noise on weekdays during work hours with stock, muffled cars and it's still a struggle.

That other MI track I mentioned has been there for 60 years, well before there were any neighbors, and it has been nearly shut down a number of times by newly moved in NIMBY's who built or bought houses without doing any research on the history of the area. The track was forced to build a 20' high, thick, wooden sound wall along the entire back straight.

Also, be sure to google the National Corvette Museum track lawsuit, it's a huge mess. That's a very recent example, track was built about 2-3 years ago and shut down almost immediately for a while. I think it's still in litigation but back up and running. I should clarify that GM doesn't really have anything to do with that track (it's owned and operated solely by the museum which is not tied to GM) so I have no inside info, just what I've read online.

Good Luck!

Alex


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PostPosted: November 16, 2016, 9:15 pm 
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Thanks to everyone for their input.

We've put together a proposal with an interesting twist that I stole from another track. The event organizer must pay the local community a Special Event Noise Permit Fee if they hold an event that exceeds the "normal" noise restrictions that we'll set on the facility. That should allow the community to do something special, something compensatory for putting up with the extra noise. Plus we've proposed restricting the number of Special Events days per year. So, hopefully community and track both satisfied. I'll let you know if it works.

Bill

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PostPosted: November 17, 2016, 11:47 am 
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That's what Laguna Seca apparently has, because when the big money-making events roll into town, the noise restrictions magically disappear, only to get set back to 90 dB when us poor folk run there. Money talks.

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PostPosted: November 17, 2016, 2:29 pm 
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It's not some conspiracy by the man at Laguna, it's right there on their website. http://www.mazdaraceway.com/track-rentals There are a limited number of 105db days set by the county, they charge $20K per 105db day. it's $7K to 10K for a 90db day.

Alex


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