I've read through most of the SCCA '06 rule book and can't find a clear definition of what's too loud for the an exhaust... (I've also searched this forum as well as scca's website)

I'm planning to run BSP next year w/ headers, race pipes, full cat-back exhuast (single 3"), will that be too loud?

thanks,
Peter

 

if you're just doing local events i dont think you have anything to worry about as far as db level goes. at least at the local events i have been to, no one has ever said anything about the db level, and i have heard some really rediculously loud cars.

 

I've read on local SCCA sites before that some will have to get permits from the town/region for the day of SOLO events so that the club doesn't get fined for excessive noise violations. As far as local SCCA officials coming down on you, I wouldn't worry about it.

 

93 is a rough range. but they put the mic near the track, not right up your exhaust cornholio, so it should be forgiving, somewhat.

 

what are the rules at nationals? (not saying that I'm planning to make it next year ~ although if the oppurtunity came up, I might do it)

thanks!

 

I always thought that noise restrictions were governed by the venue not the organization.

 

For the San Diego region the noise limit is 91db and its strictly monitored and enforced. The San Diego NT typically has few, if any, Prepared or Mod cars because of the noise restriction demanded by Qualcomm stadium.

The CalClub region has a 95db limit and its rarely monitored and I've never heard of it being enforced.

YMMV...

 

Check with the clubs you want to run with. They should note any noise restrictions on the announcements for their events. Then go and let them measure. I think you might be surprised that the Z doesn't get into the high 90's.

For SCCA events the rulebook says
3.5 MUFFLERS
Adequate mufflers are required for Solo 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.

Noise limits are dictated by the locale and how much the region wants to continue to run there. Good sites are very tough to find and keep, especially in populated areas.

In the Southeast, Atlanta has a well defined set of rules with a 96 db limit at the Gwinnet County Fairgrounds and they are very strict. TVR has implemented the same rules (why reinvent) in Huntsville as a pre-emptive measure for our primary site because of the close proximity of residential property. I've had to DQ a long time SCCA member because he failed on his 1st run and said he couldn't quiet his mod car for a 2nd try.

At Nationals, I don't remember anything in the supplemental rules about noise. Being in the middle of a road race track, next to an Air Force Base and with a railroad running by, noise wasn't a consideration.

 

I do know of a stock Z06 (running SS) that failed to pass sound at a national tour event for two runs.

So yes, it is possible that a stock vehicle can fail sound.

 

Actually San Diego is 93 db @ 50' and they check every car every run. Cal Club is 95 db @ 50' but they do not even get out the db meter unless someone shows up with a crazy loud car. The difference between 93 and 95 db both at 50' is huge.

Currently there is no SCCA Natl standard or even a limit for the Solo natls. They are looking into establishing a natl standard for how the measurements are taken, I know because I had to contact all the regions that have a limit and see what it is and how they measure it, but most of the time the sound limit is set by the city/county/track and not the club.

San Diego is one of the most stringent in the country on sound, lots of houses up on top of the hill where they run. Every year a number of cars will get a DSQ for sound at the SD Natl tour. The only Z06's in SS I have seen get the DSQ were cars with strait pipe or the Borla system. For reference my RX8 with a custom built single exhaust is 89 db @ 50' in SD.

 

thanks for the help guys...I looked up my local group - 102 dB @ 25 ft, WOT. We run at the Boeing parking lot in Everett, Wa...another member says that the group doesn't really check --> with 747's taking off a few hundred feet away, cars don't sound like much.

thanks again!

-Peter

 

Another reason I don't autoX...

 

This is not an autox only item. Many road courses and drag strips also have sound limits. PIR, Laguna Seca and many others. I know someone in CA that got pulled over on the freeway a got ticket for exhaust that was to loud, the same car would go over the 93 db limit in San Diego once in a while.

 

I have never had an issue with the noise level of my exhaust at any local tracks. (Mid-Ohio/Putnam Park or any dragstrip here in ohio)

 

As population closes in on existing tracks this becomes more of a problem. It is BS imho as the tracks were there first, but tax dollars and votes of home owners have a way of killing tracks.

Laguna has a 90 db limit, they have some days they get a 92 db limit and a few days a year for special events with nothing.

PIR in Oregon has one for the road course and drag strip, city owns the track. You get the idea. If tracks in populated areas want to stay open they have to be good neighbors.

 

And if you don't think that cranky homeowners won't close tracks, look at what has happened to some airports! No night flights, noise abatement procedures (which is a "nice name" for chopping back the throttle on takeoff -- just when the aircraft needs it the most!), closed runways or airports, among other things!

It's only a matter of time before more tracks here in the US put noise limits, simply because cars are "politically incorrect" here. If you lived in other areas of the world, you'd pay MORE to live near a track!

 

WOW I just heard that Lime Rock is 89 db @ 50'.