Track day noise limits/exhaust testing

[X Malik]

Hi all, before i go on track days i was wondering about the noise limits on track days.
My exhaust is rather loud so before i go on one i kind of want to check the noise level so i do not get disappointed on the day.

i have been looking around at the average limit that most tracks allow you to have and bought myself a Digital DB meter.

Does anyone know the testing procedure? so i can test my exhaust properly

I've conducted one test by standing about 4ft away from the exhaust at low level and getting the engine held at about 4,500rpm. The results were averaging between 104-106db.

If they was to be the correct noise results for my car, would i have a problem? as most tracks tend to have a maximum noise level of 105db

 

[Shaenei]

It's contained in the blue book and is mentioned over on hondas on track quite often, I'll see if I can find the info

 

[Hazz]

My friend with a turbo EG is forever moaning about noise restrictions at tracks. Trouble with Honda's and noise limits is that often the tests are done stationary... where you cant engage vtec. You might pass the test but if the marshalls are feeling anally retentive, they might pull you up after a lap or 2 for being twice as loud as everyone else.

I think it's 1 metre away but don't quote me on that. He said some tracks have the DB meters trackside now too, so there's no cheating your way through :\

 

[Shaenei]

im really worried about the decibel limit,
where abouts is it measured from and at what rev's ?
i have an s2000 with twin exit exhaust so do they measure both cans?

rob

From the blue book...

5.18.1. Measurement will be made at 0.5m from the end of the exhaust pipe @ an angle of 45 degrees and @ 3/4 max RPM...

5.18.2. Where more than one exhaust outlet is present,,, the test will be repeated for each exhaust and the highest reading will be used...

It is also worth noting each track has it's own limits, static test limits seem to be between 95-100 db

 

[X Malik]

Very useful information there, i have a feeling I'm going to fail judging by 5.18.1 lol
but as hazzthejazz has said, you cant engage the vtec when stationary. which is where the 3/4 area is around....

 

[Harv]

go down to your nearest track when theres a trackday on and ask them for a test, they will be fine with it.

 

[X Malik]

go down to your nearest track when theres a trackday on and ask them for a test, they will be fine with it.

The closest one is Donnington, but thats like a construction site at the minute! the next one is Cadwell or Mallory park.

I'll be checking my exhaust tomorrow with the same procedure Shaenei has posted. if my exhaust is too loud which i am assuming it will be. does any one have any experience with clip on external mufflers which clip on the tail pipe?

http://www.decibeldevil.co.uk/

The idea came to my head to Google it when i remembered i went on a day experience with a Lamborghini and they had to have them fitted!

 

[Ash_EP3]

I'd imagine mine is massively over the limit, but I've got launch control so I don't see how they'd be able to test it anyways?

 

[Lottie]

I'd imagine mine is massively over the limit, but I've got launch control so I don't see how they'd be able to test it anyways?

You need to switch it off.

Bungs can be used or alot of people just switch back to the OEM back box for the day...or get a sensible exhaust that can be used on track

 

[X Malik]

You need to switch it off.

Bungs can be used or alot of people just switch back to the OEM back box for the day...or get a sensible exhaust that can be used on track

how do these bungs work? im gonna have to go something. im getting read outs of 110DB when im going through the gears on the inside of the car... wouldn't like to know the read out outside!!