laguna seca db thread

[bkblitzed]

Since a lot of us track our cars, and go to laguna seca I thought about making a thread about what exhaust will pass and won't pass for laguna seca.

My catless tomei El with catless resonated invidia front pipe, invidia overpipe and trd cbe did not pass at a 94.4 db. But putting my stock front pipe quieted it down to a 92.3 which still didn't technically pass, but the marshals didn't seem to care for the afternoon sessions

[EAGLE5]

Stock passes just fine, even with a Borla EL header.

[gramicci101]

This has been brought up before, although not directly relating to what passes and what doesn't. Here's my answer from that thread.

Originally Posted by gramicci101

I couldn't find the decibel measurement of a puppy's bark, so we'll go with grown dogs. The world record dog bark was set by a white German shepherd at 108 dB. It isn't fair to use the record holder, so we'll assume an average of 100 dB. The dB limit at Laguna Seca is 92 dB, which seems very low. Also, neither Guinness nor Laguna Seca's site listed how they measured, so I'll assume it's at 1 meter, since that's the standard.

Since decibels change on a logarithmic scale that requires double the power for a 3 dB increase and half the power for a 3 dB decrease, then 1/8 of an adult German shepherd will produce 91 dB and be legal to run at Laguna Seca.

Math, bitches.

[spitz]

Greddy SP Elite will pass. Lol.

[Chopstick]

If anyone wanted to know exactly how and where they measure sound at laguna this is a very good resource. http://scca.cdn.racersites.com/prod/...na%20v3%20.pdf

[mav1178]

Point your exhaust to the left of the car. It will also pass that way.

-alex

[PMok]

I heard unconfirmed rumors that they have a 2nd mobile sound monitoring unit that can be placed in other parts of the track. Has anyone else heard of this? No mention of it in the presentation that was shared by @Chopstick though, and that seems to be a fairly recent presentation (from earlier this year).

[sw20kosh]

Originally Posted by mav1178

Point your exhaust to the left of the car. It will also pass that way.

-alex

This idea wont work if they have a sound station on the inside of the track... and rumor has it they are using one of these new sound stations now. Anyway we can confirm?

[gramicci101]

Originally Posted by Chopstick

If anyone wanted to know exactly how and where they measure sound at laguna this is a very good resource. http://scca.cdn.racersites.com/prod/...na%20v3%20.pdf

So they're measuring your volume as you come off an apex and are likely at WOT. I think my car is over 92 dB at WOT, and I have a completely stock exhaust system.


Although they're measuring from 55 feet away. That means you can be about ~125 dB at 1 foot and you'd be right on the line of acceptability.

[sw20kosh]

Originally Posted by PMok

I heard unconfirmed rumors that they have a 2nd mobile sound monitoring unit.

Ncrc responds:

"I think it's just a rumor Kevin. The only sound station we've ever seen is the same one on driver's right at T5.

Dave"

[PMok]

that's good to know, i will stop spreading that rumor myself haha.

I wonder if anyone has ever wandered over to the sound monitoring station, offered an ice cold beverage (or a warm one if it's cold out) and a smile, and kindly asked if the sound guy or gal could look the other way every time a certain car went by... just long enough to miss the sound reading.

[bkblitzed]

well last weekend there were cars with the laguna seca muffler, but none of them got meatballed, so no i dont think there's ever going to be a sound station on the left side. Hell i think i was the only 1 that did get meatballed lol.

[EAGLE5]

You can always just half-throttle or slow down on that corner. Works if you don't have an insane exhaust. The other day, some guys were bolting soda cans onto the end of their exhaust.

[bkblitzed]

well after i put my stock front pipe i didnt get meatballed. So didn't really bother me much.