to loud at tremblant ?

[miatapeter]

Thanks for the welcome Bruce. You and I have a little history on sound.
I don't believe NHIS has run any sound readings since Ted Goddard left.
My thought is to do sound readings during a TT when the cars are spaced and in groups. It may not work for this weekend, but we could try for Oct., and/or the first outing in 2011. I am open to any and all sggestions on the best way get readings.

[Grippy]

Peter, I saw you out there with the meter, did you make a list of cars and readings?
You told me that I recorded 106db! That seems a bit high even for a Miata

[timmmy]

woah 106 for your Miata does seem loud Gordon, given it wasnt the loudest miata there. I would be interested in seeing some results too, I didnt know the meter was being tested this weekend.

[jeffw]

woah 106 for your Miata does seem loud Gordon, given it wasnt the loudest miata there. I would be interested in seeing some results too, I didnt know the meter was being tested this weekend.

Can Will and I have a loud-off? Not sure who's louder...

[nateh]

Peter and I (Peter, especially) took a number of measurements at Loudon. I will post them as soon as I get a chance.

We got much higher values there than we would have at Tremblant, because for convenience we were checking on the start-finish straight, and the walls and stands trap and amplify the sound. Subtract about 9 dB from anything we measured there in order to convert it to Mt Tremblant levels.

[jadams]

Wow....I would love to see the formula you used to come up with the 9db difference between NHMS and Mt Tremblant! It must have a lot of variables!

[nateh]

The math is extremely subtle and complex. Erm, ahem. Actually, no.

We ran our car at both Tremblant and NHMS. We were not dinged for sound at Tremblant, and therefore must have measured no more than 92. At NHMS, Peter got us at 101. Ergo - at least 9 dB difference.

Mike Kuno was another example - busted at Tremblant for running 92.2. On the front straight at NHMS, he blew 101, 104, and 106.

Peter took data on about 45 cars:

Car# Session
dBA readings
00 1 106 106
044 2 102
10 2 105 106 104
11A 1 109 109 107
12 1 95 96 95
30 1 112 111 110
47 2 101 101 101
48 1 100 100 100
55 2 102 101 101
67 1 113 111 113
87 1 112 112 112
97 1 98 98 100
140 2 88 89 88
215 1 101
274 1 106 104 101
646 1 90 89 91
892 2 95 93
120 3 98 98
123 3 97 97
142 2 97 96 97 97 96
183 3 89
250 3 92
305 3 93
330 3 95
345 2 90
351 2 88
413 2 99 100 100
426 3 94
46 2 100 100 100
49 2 105 105 106
512 2 97 97 97
6 3 88
61 2 93 93
641 3 95 94
646 3 91 91
72 2 97 100 100
76 2 97
779 2 91 92 93
781 2 104 405 104
809 3 95 95 96
841 3 89 89
88 2 94
892 2 94 94

I have a PDF of the original data for anyone who is interested.

[jeffw]

The math is extremely subtle and complex. Erm, ahem. Actually, no.

Car# Session
dBA readings
781 2 104 405 104

Woohoo! I win!

Um, what do I win?

[jeffw]

The math is extremely subtle and complex. Erm, ahem. Actually, no.

We ran our car at both Tremblant and NHMS. We were not dinged for sound at Tremblant, and therefore must have measured no more than 92. At NHMS, Peter got us at 101. Ergo - at least 9 dB difference.

People may run a different exhaust setup at different tracks. I've got one for Tremblant, and a different one for LIme Rock.

[nateh]

Right, and I didn't ask Mike if he changed his. But we didn't change ours.

[chaos4NH]

The math is extremely subtle and complex. Erm, ahem. Actually, no.

Car# Session
dBA readings
781 2 104 405 104

Woohoo! I win!

Um, what do I win?

Jeff, I made a quick call to another BOD member who suggested we would present you with a 32" TV! It will fit in your hauler well and provide hours of enjoyment!

[nateh]

Disregarding my typo, I think Pat McMahon should get the golden earhorn.

[brucesallen]

Strange, but I show 112 dB but Peter measures me at low 90s from the same point at SCCA races. I'd like to hear what Peter says about this.
BTW: I borrowed Peter's meter at the last NHMS SCCA race where they had free food and a Country band. The band measured 104 dB at 50 feet and 112 on the dance floor. Dancing is unsafe.

[nateh]

In SCCA races, Peter does the measurement from the inside of turn 10. That's another example of how big a deal the immediate environment is.

[jeffw]

The math is extremely subtle and complex. Erm, ahem. Actually, no.

Car# Session
dBA readings
781 2 104 405 104

Woohoo! I win!

Um, what do I win?

Jeff, I made a quick call to another BOD member who suggested we would present you with a 32" TV! It will fit in your hauler well and provide hours of enjoyment!

My sponsorship contract only allows me to have flat screen TVs, since I only drive flatout.