Laguna Seca - dealing w/ 92 dB noise limit?

[Richard EVO]

For those NSX owners who track their cars at HPDE events at Laguna Seca in NorCal, do you make sound on a 92 dB day (which is the noise limit on most open track days)? I have comptech headers an a aftermarket exhaust, and don't want to make the trek all the way from SoCal, just to get meat-balled for sound.

And if you have some kind of an exhaust turn down, please explain or show pics of it. A lot of other cars I have seen add a pipe to each exhaust tip that points away from the sound measuring station on the right side of the track on the uphill straight between Turns 5 & 6.

Thanks.

 

[g3driver]

I to would love to know this answer.. I am running OEM manifolds,cats,and a GTLW. I think I will be ok but does anyone know?

Noise limit at a track?? geez! I wonder how other races get that waved?

 

[Dhalsim]

as a last resort you could just lift off the gas at that turn. It's just an HPDE and not like your running for pinks.

I have never had a problem but my exhaust isn't really that loud and I have no idea how loud yours is.

 

[nsxnut]

Aftermarket exhausts usually won't pass sound as is. You may get buy for a while but as the weather changes the reading will as well.

You can go to home depot and get some aluminum 3" vent pipe swivels
and configure them to be a 90deg bend. Aim them Up to the Left.
Get some large hose clamps and torque them down good and tight.

Stock setup will pass.

 

[Hrant]

Aftermarket exhausts usually won't pass sound as is. You may get buy for a while but as the weather changes the reading will as well.

You can go to home depot and get some aluminum 3" vent pipe swivels
and configure them to be a 90deg bend. Aim them Up to the Left.
Get some large hose clamps and torque them down good and tight.

Stock setup will pass.

What he said - except that "occasionally" a well breathed OEM exhaust may not pass either depending on weather conditions; that is when lifting helps.

 

[nsxnut]

What he said - except that "occasionally" a well breathed OEM exhaust may not pass either depending on weather conditions; that is when lifting helps.

You can also make turnouts for the stock exhaust. :smile:
Cheep insurance.

 

[Richard EVO]

I to would love to know this answer.. I am running OEM manifolds,cats,and a GTLW. I think I will be ok but does anyone know?

Noise limit at a track?? geez! I wonder how other races get that waved?

One guy who bought his house AFTER the track was built (and he knew it was there) sued the County of Monterey, which owns Laguna Seca, complaining that the noise from the track was a nuisance. He won and got an injunction against the County. Under the injunction there are a very few 103 dB weekend days allowed per year, and these are used for the few professional races that run at Laguna each year. Almost all the rest of the days are 92 dB limited, which is what amateur race organizations and HPDE groups get. It's all a giant pain in the a$$ and takes a lot of the fun out running Laguna.

 

[itrsteve]

Such a shame you guys have to go through this. I got to see the track in person last Friday and it looked amazing and I will admit it was quiet and a little peaceful, sort of surreal for a race track I thought.

 

[2slow2speed]

FWIW, when they have the mobile setup lifting between T5 and T6 won't help.

I used to get black flagged for sound at Laguna with the NSX with Comptech Headers, Comptech Exhaust and Cantrell Concepts Style air intake, lifting between T5 and T6 didn't help.

 

[docjohn]

for anyone with the gtlw exhaust taitec makes silencers which screw into the exhaust outlet and do a pretty good job.Helped me pass lime rocks 89 db sunday limits.

 

[deviljapan]

One guy who bought his house AFTER the track was built (and he knew it was there) sued the County of Monterey, which owns Laguna Seca, complaining that the noise from the track was a nuisance. He won and got an injunction against the County. Under the injunction there are a very few 103 dB weekend days allowed per year, and these are used for the few professional races that run at Laguna each year. Almost all the rest of the days are 92 dB limited, which is what amateur race organizations and HPDE groups get. It's all a giant pain in the a$$ and takes a lot of the fun out running Laguna.

OMG this is ridiculous, buying a house near a circuit and complains for the noise..?

 

[92 white 0650]

Re: Send lawyers, guns and money - W. Zevon

OMG this is ridiculous, buying a house near a circuit and complains for the noise..?

Happens a lot in the U.S. with old, small, general aviation airports too.

Yep, ridiculous. Just like so many other things when too much money and too many lawyers are available.

Just to summarize the Laguna sound "budget". The County allows a few pro events that have no sound limits. Other race events, like SCCA, have sound limits that are highest (103) in mid day and less (down to 95, I think) early and late in the race day. And so, the HPDEs are bottom of the totem pole; and are always 92, to my knowledge.

Edit; agreed that Laguna is not much fun anymore but, IMHO, due mostly to the huge MC friendly gravel traps. Back when the economy was good and the formula/sports racer grid was 50+ cars, SCCA races often had more yellow laps than green while the tow trucks pulled cars out of the gravel just a few feet off the pavement.

 

[NSXDreamer2]

our creation at PIR when i got black flagged mid day. even with Silencer. This is when i had the taitec jgtc with comptech header and test pipe. ugly and it's very temporary.

For Laguna, you may want to leave the cat on the car. You may get by with silencers.

 

[Richard EVO]

That's what I'm looking for, but at Laguna, drivers point them to the left and up, not right and down. Sound measuring station on uphill straight to the right of track. Can you post a DIY on how to do that set up? Thanks.

our creation at PIR when i got black flagged mid day. even with Silencer. This is when i had the taitec jgtc with comptech header and test pipe. ugly and it's very temporary.

For Laguna, you may want to leave the cat on the car. You may get by with silencers.

 

[stuntman]

That's what I'm looking for, but at Laguna, drivers point them to the left and up, not right and down. Sound measuring station on uphill straight to the right of track. Can you post a DIY on how to do that set up? Thanks.

A DIY?

C'mon richard...

1-buy 90* tubing (ID of your exhaust tips OD - or get same OD and cut a slit in the end to spread it over your exhaust tips) & hose clamps

2-slip 90* tubing over your exhaust tips

3-clamp it down.

:tongue:

 

[Hapa88]

Borrow someone's 1991-1994 stock exhaust for the weekend.
Also, if you have an iPhone you can buy a cheap dB meter for $0.99.
I have this one and it's within +/- 1.5 dB from my real RadioShack SPL meter:
http://www.studiosixdigital.com/spl_meter.html

Also keep in mind that the limit is 92 dB(A), where the "A" weighting filters out low frequency sounds (i.e. deep sounding exhausts).

 

[ryneen]

I have comptech headers, test pipes and Taitec GTLW exhaust. I simply bolt on the stock mufflers and I pass sound with no problems.

 

[Richard EVO]

I have comptech headers, test pipes and Taitec GTLW exhaust. I simply bolt on the stock mufflers and I pass sound with no problems.

Great to know. My car came with all the OEM parts, so I still have the stock exhaust and could bolt it on.

 

[ryneen]

Great to know. My car came with all the OEM parts, so I still have the stock exhaust and could bolt it on.

The stock exhaust will make your car sound like a hybrid. Super quiet.

 

[Hrant]

The irony in here - ie Laguna Seca - is going to the track by adding a restriction to performance rather than enhancement!

 

[Track Addict]

It is a sad truth that Laguna Seca has such a low Db restriction, just bolt on the stock muffler and have fun. You'll be having so much fun that you'll forget all about the small decrease in performance.

 

[Hapa88]

Great to know. My car came with all the OEM parts, so I still have the stock exhaust and could bolt it on.

This is, by far, the easiest and safest thing to do. There's a total of 4 bolts and 2(or 4?) rubber hangers. Should be a no-brainer..

 

[RYU]

I'd like to bump this thread for more examples from NSX folks who have passed sound.

Last time [MENTION=6942]ryneen[/MENTION] and I were there I wasn't black flagged (I think it was a 96DB day?) but he was on his comptech headers, test pipes and Taitec GTLW exhaust. It's really not a perfect science the way they test for sound... His car is quieter than mine.

I'm looking to revise my setup to meet MRLS 92DB sound days. Going to be a uphill battle.

I think turn-downs will be mandatory.

 

[Dhalsim]

you going on 12/26?

 

[mcano]

you going on 12/26?

Roger, I'm going to Laguna Seca at the end of 2016 with the Alfa Romeo Club. I thinks I'll make the exhaust tip modification. I have a 97 with OEM headers, and Pride II exhaust. Its louder than OEM, but not as loud as other after market exhaust systems.