PCA SDR

The new sound meter is pretty much dialed in and accurate.
We are still investigating a final measurement methiod to use.
The following measurements were made 50 feet from the track with no large object within 100 feet (Highway Patrol & SCCA method)
Only measurements over 90 dBA were recorded.
The results are:

Meeder = 93.9, 92.9, 94.1, 92.4, 92.3, 92.6 (way less than before due to mods)
R. Schuessler = 96.9
Binford = 97.9, 96.6, 96.1, 91.9, 92.5
Corwin = 94.4
J. Chambers = 90.1, 91.4, 93.2Barnum = 97.0
Matsumoto = 90.7
Cunneen = 94.7
Bray = 97.3, 98.4, 98.3, 96.4
Hansen = 90.8, 90.3, 92.5, 92.5
Wierenga = 96.3, 96.8, 95.0, 96.5
Choi = 90.1
Doran = 90.5
Morgan Trotter = 97.5, 97.1, 97.4, 97.0, 96.1
Ron Trotter = 95.1, 95.5, 94.2, 94.6, 93.8
Fenstermaker = 91.3, 94.4, 91.9, 94.2
Sampsell = 101.5, 97.7, 94.3, 99.6, 96.4
Kolley = 91.1, 91.4, 94.8, 94.6
Lisa Goetsch = 94.7, 96.9, 96.4, 97.2
Kollars = 94.9, 93.8, 95.2, 94.5
Fowler = 90.3, 90.9, 91.7, 91.2
Angela Avitt = 90.4
Holzinger = 90.0
Burch = 93.0, 93.2, 93.0, 93.7, 93.3, 92.9
Copelin = 91.5, 93.0, 93.4, 92.0, 92.1
Mike Avitt = 91.8, 91.1, 91.8, 92.2
Young = 95.7, 95.1
Comeau = 97.5, 97.2, 98.5, 97.2, 98.3
Erik Kinnenger = 95.0, 95.6, 94.3
D. Malmberg = 90.1, 90.3
Tweed = 96.0, 95.7, 97.0
Elumba = 94.4, 94.9

I hear Mark Kinnenger was there with some modification items and a simple bent exhaust pipe pointing up at 45 degrees and away from the sound meter might do the trick for a lot of folks to reduce the sound.

I hear Mark Kinnenger was there with some modification items and a simple bent exhaust pipe pointing up at 45 degrees and away from the sound meter might do the trick for a lot of folks to reduce the sound.

Now isn't that just a cheat? Pointing the exhaust away from the sound meter does nothing to reduce the sound but directs the existing sound pressure signature away from the monitoring equipment. For example, If the equipment is moved to the opposite side of the track later in the day, won't the effect be increased? For all we know, directing the sound away from the eqipment may just be pointing it directly at the most likely complainent.

Don't get me wrong, I'm all for us designing a methodology for testing and recording our sound presence at the "Q" and anyone who can devise a way to reduce or eliminate their name from showing up on the violators list gets my kudos, regardles of the method they use.

I'm just throwing it out there because I like stirring the pot.

Now I know I have put my foot down harder. Morgan was louder then me in the same car. My bad.

ronaldtrotter wrote:Now I know I have put my foot down harder. Morgan was louder then me in the same car. My bad.

No, Ron, your good. I saw that and thought, Ron can give us all lessons in sound modulation and we cannot forget about the meter, the regs and exhaust mods And, now you say it is as simple as putting your foot down

Well, after noticing that 2 of my KI competition Jim and Tom are above the limit - I suggest that a good solution to this problem is to ADD 2 SECONDS to their times!!!!!!


Of course, we haven't had the pleasure of being measured yet.

Another cheat besides pointing the exhaust away, we can try short shifting too.

Another cheat: Just hire BOSE to come up with a noise cancelation system as they have with their head phones, which looks at the noise spectrum and then generate the same noise 180 degrees out of phase with it (and equal amplitude) so the 2 add together to equal zero. (Or does the power of each add up to twice the original amount?)

That's it. I'm installing more bass in the car. The "ca-boom,boom,boom" should cancel out the car noise. Same cost as a new exhaust system.

ronaldtrotter wrote: Morgan was louder then me in the same car.

Heck, I was louder than me in the same car. I'm having trouble feeling confident in our methods when results are varying by such a wide margin. Last event I was 91.8 dB and this time I measured 97??? That's a huge swing for the same driver in the same car. What was different about the technique used to measure this time vs. the 10/24 event?

TT

Tom - I don't know what the differences were as I didn't take the measurements but maybe the earlier AX the meter was set at a place where folks were not really on the throttle.

Let's both look at the meter and location set up next time you are there.

(Did you take tips from Morgan Trotter on how to drive louder?)

Did some one post the sound levels at the AX? I was looking to see how loud my car was. I want to eventually install a different muffler on my car and was wondering how much louder I can be.
I can't believe my car is not as loud as Terry Barnum's. His car measured 97 dB!!??

Did some one post the sound levels at the AX?

The sound levels were not posted as after the first run session. Lorri and crew gave them to me (AX co-chair) and they are not in a form yet to be posted. We are still working everything out.

Morgan Trotter too me over to the SCCA course running in the SE lot and we got a form they use to tabulate cars/sound levels which will make posting easy.

We are still refining this sound measurement thing. I have to propose to the Board December 2 a method for measuring sound for their approval and how this will all be enforced. I'd think it will not be enforced until February or March?

Also (can't remember if I said this before), I took measurements at the property line at the NW corner and climbed the hill and stood at the apartments and took measurements. There were only 3 or 4 cars I really noticed over the Friars road traffic noise.

I took measurements at the property line at the NW corner and climbed the hill and stood at the apartments and took measurements. There were only 3 or 4 cars I really noticed over the Friars road traffic noise.

Then I propose that is where we set up the monitoring equipment! Seems like a slam-dunk to me.

Herb - you bring up a good point.
"Now the 'fun' begins......93 dBA at the property line?

San Diego Municipal Code actually has noise limits at property lines. Don't have the info right in front of me but I recall the highest limit is 75 dBA for "Industrial" = uh, oh ..... many cars over that at the property line.

City Code doesn't have the Stadium specifically listed so let's say 93 dBA at the property line. We're OK now...... maybe?

City Code says 65 dBA at apartments/condos. Uh oh, the loud cars measured 80+ at the apartments. Means quite a few measure over 65 at the apartments.

Where 2 different zones abutt (do they abutt if Friars Road divides them?) you get to split the difference = 93??? + 65 / 2 = 79 dBA Now only the 4 or 5 loud cars are over.

I don't have a definitive answer on this and certainly don't want to ask the stadium of city.

Are there any land use lawyers in the club that give guidance on this?