Track decibel limits

[ViperGeorge]

Just had my 06 Supercharged Coupe to the Lightning Track at NJMP. The event was put on by SCCA. They black flagged me for exceeding a 103 DB limit as I entered the straight. They said I hit 105 twice. My car has the Random Tech High Flow Cats and Corsa exhaust. Problem is the exhaust points right out the side and directly at the sound pickup van. Other cars were clearly louder but they had exhaust tips pointing away from the sides of the track to fool the sound pickup. Some even had their exhaust tips that they would turn to point away from where ever the sound pickup was going to be.

Anyone have any temporary solutions for quieting their Viper or redirecting the output towards the ground? I would only want to quiet her down at tracks with sound limits. Oh, the Chief Instructor realized that their sound limits were not in effect that weekend so I was actually black flagged for nothing. None the less some tracks do have limits.

 

[8mywal8]

Thank all the butterfly chasers we let have a say in this country. They move next to an airport and then complain.

 

[Tabs1]

Not good for your times, but you have to let off the gas as you drive by the pick-up mic.

 

[ViperGeorge]

Not good for your times, but you have to let off the gas as you drive by the pick-up mic.

Yea that is an option but they usually put the darn listening stations on the main straights. It would be a real bummer to have to lift at those points; takes all the fun out of it. I'm really looking for a diffuser of some kind that can be temporary installed in the outlets for those tracks that have noise limits. I want them to be easy to put on and take off, hopefully without taking the sills off. I think Supertraps are permanent but someone at the track recommended them but he wasn't in a Viper.

 

[Leslie]

I have corsas and high flows too, so far I have only hit around 85db

 

[Steve-Indy]

The side pipes register louder as compared to rearward exhaust.

 

[Boxer12]

Do you have your tips angled slightly downward? That's what I did.

 

[ViperGeorge]

I have corsas and high flows too, so far I have only hit around 85db

I was surprised that they said it hit 105 but they said that they saw it twice. Quite honestly I thought there were Miatas that were louder than my Viper.

 

[Leslie]

The side pipes register louder as compared to rearward exhaust.

Yehp that's why

 

[Chuck 98 RT/10]

Thank all the butterfly chasers we let have a say in this country. They move next to an airport and then complain.

Nobody gave you thumbs but we're all thinking the same thing. Never heard them called "butterfly chasers" before. I always call them p*ssies.

 

[Kai SRT10]

You might try the dynatech vortex cones. They can take a few decibels off without any reduction in performance.

 

[ViperGeorge]

You might try the dynatech vortex cones. They can take a few decibels off without any reduction in performance.

Thanks. This is pretty much what I'm looking for. Do you know how easy it is to install them? Do you just slip them in the exhaust tip or do they have to be welded or bolted in somehow? From what I've read they seem to reduce db levels by 2-3. That would have got me by the SCCA limits but I'm not sure about all tracks. Does anyone know what the limits are at your typical track? I think Lime Rock is really low.

 

[Leslie]

I do know when I was in a different track car I hit 90 db at Beaverun during Viper days...and they told me that was the track's limit.

 

[Leslie]

You might try the dynatech vortex cones. They can take a few decibels off without any reduction in performance.

here's a thread on them

http://forums.viperclub.org/rt-10-g...vortex-insert-cones-end-tailpipe-results.html

 

[VIPER GTSR 91]

I recently watched the 25 hour enduro Narra race in Calif. on tv and the same thing happened to several cars with side exhausts. The decibel meter was on the side of the track so a few changed their outlets to the rear and all was well. Kind of a hassle though.

 

[NI-KA]

I guess this is one way to get rid of really cool combustion engine driven cars.

As it typically goes, start by instituting a standard that only affects a few, then make it progrssively more restrictive so only a few notice or complain.

Before we know it only electric cars will pass this test...

 

[Sneaky Pete]

Thanks. This is pretty much what I'm looking for. Do you know how easy it is to install them? Do you just slip them in the exhaust tip or do they have to be welded or bolted in somehow? From what I've read they seem to reduce db levels by 2-3. That would have got me by the SCCA limits but I'm not sure about all tracks. Does anyone know what the limits are at your typical track? I think Lime Rock is really low.

I came across your post while looking for solutions to quiet my car for use at Lime Rock, if it's even at all possible.

I was thinking of adding Dynatech Vortex Insert Cones at the exit of the headers and then install the longest 3" muffler(s) I can possibly install in the sills. I doubt this will even get me low enough to beat the sound police at LRP. If not, I can always install another set of sound cones at the side turnouts. If that still doesn't meet their requirements, I can always pack some metal mesh in behind the exit cone until it passes... or the car over heats and chokes to death!

Thoughts (other than not driving at my home track)??? Anyone know what the longest muffler length is that will fit in the sills?

BTW, I have a GTS, not a gen 3/4...

 

[usurbrain]

Anyone have any temporary solutions for quieting their Viper or redirecting the output towards the ground? I would only want to quiet her down at tracks with sound limits.

You can do what I'm going to do at Laguna Seca. Not drive it... jk. don't point towards the ground, the sound will bounce off the ground and be loud. either point towards the back or up and away from the meter. If you use a Supertrapp, make sure it's welded on. I clamped my on my Exige, and it popped off, and melted my clam. That sucked. Though it does suppress the sound enough to be below 92db.

My Paxton Viper has RT HF cats, and a corsa track exhaust, and it's FAR louder than the Exige was...

 

[Sneaky Pete]

FWIW, I just heard back from Lime Rock Park, their noise limit is 88db.

 

[SlateEd]

Hooray for the search feature... resurrecting this thread to see if anyone has tried a Gen 3/4 at Lime Rock on a noise-limited day? Any luck with just lifting off the throttle? Any idea what method they use to measure, and if they're setup all day or just spot-checking?

(The limit for this coming weekend with NASA is posted at 84db... unless the sound is measured from a football field away I don't think I can get under that SPL)

 

[Richie7]

Ed we are going to be racing in 6th gear to get under that limit!