Bike decibels. How to get a number?

A

afinepoint

Member
Some tracks have noise limits. Jennings, for instance, states "Bikes exceeding 104db will not be allowed on the track.

Where/how do you measure the bike for this? Is this xxxdb at xx feet? At a certain RPM? Who does this for you?

I'm sure no one would want to sign up for a track day, get to the track and end up a spectator.

Thanks.
 
vice

vice

New Member
At laguana the they have a meter at a specific turn (7?) Everyone with a questionable exhaust knows to slow down/stay off the throttle. A lot of tracks actually have a restriction its just loosely enforced.
 
EngineNoO9

EngineNoO9

Member
Unless you're running a slash cut exhaust or a D&D, you should be fine. Those were always the two that annoyed the piss out of me at the race track.

If you're desperate to get a number though, I know you can get sound meter apps for Android and I assume probably for the iPhone as well. It should at least give you a general idea of where your bike is at. I'd start a measurement at the bike then walk away to get an idea of what the readings are. You might annoy your neighbors though if you're sitting there holding the bike at near WOT for awhile though...
 
matt2212

matt2212

Member
What kind of system do you have?

In my experience very few bikes even come close to having a problem, the only time I've seen a problem was at Jennings and it was Danny Eslicks EBR super bike. It was LOUD, he was wide open and was barely over the 104 db limit


Sent from my iPhone using Tapatalk
 
Kruizen

Kruizen

Control Rider
The problem your going to have is that most tracks measure while your on the track, under acceleration, from a specific angle and you would need to replicate those conditions.

I believe that NJ has restrictions, but as stated above loosely enforced, especially for a track day. A national event, AMA etc. they will staff the decibel station.

As asked above what type of bike and what system, I'm sure others will have a similar set up to let you know their experience.

I'm running a Buell 1125R with a Drummer exhaust that measured 102.5db at static 2K RPM, and 111.4db at static 5K RPM. While I haven't been to Jennings, I haven't had problems at NJ, Summit, VIR, NCBike
 
JGardy_781

JGardy_781

Member
A decade ago, before my first trip to Jennings, I called the track staff and asked the same question - they said as long as the bike has a "normal" race exhaust, you're fine. The noise max is really in place, from what they told me, to protect against open exhausts (slash-cut type stuff without mufflers), and there are some local noise ordnance requirements to suit the track's "neighbors". Been to Jennings tons of times over the ensuing years, and never had any sort of problem, nor ever seen noise measurement hardware in place or in use.

Hope this helps with Jennings, at least.
 
haze748

haze748

Sammiches
Was reading through this thread thinking about my setup. 2007 R6 with a full Leo Vince no db killer. Assuming I should be okay at Road ATL?
 
rugbymook

rugbymook

Control Rider
Race Director
Call your local police department and see if they if they have a sound level meter. Many stations have them and can give you a precise db measurement.
 
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