[pazzer]

well having had my rs barn headers and system fitted with a de-cat pipe, its too bloody noisy to go on track. at 5400 rpm's its registering 109db's <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" /> which is well over the noise limits here in the UK, i need to get it down to about 95db to be sure it will pass on all the circuits i intend to go to. does anyone have any ideas to reduce the noise with minimum loss to power, or would it be simpler just to add the rs barn hi flow cat, your comments are much welcome, <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" /> regards chris

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[flash]

that is pretty danged loud - 109 with what weighting and at what distance?



well, first order of business is to install the cat - that should get you down 5db - it will run better that way anyway - the resonator would take out another 10, but you'll lose some of the throttle snappyness

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[Eric_K]

My car measures 96-99db from trackside. This is with RSBarn headers and test pipe but B&B cat back. Are you sure you put a muffler on it? <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" /> 109 sounds too high to be right.

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[pazzer]

Hi Eric, yes it has the muffler as you call it at the rear just one box, then the tail pipe, basically its a straight through system with one box at the rear, what configuration is the BandB, regards chris.

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[Eric_K]

My B&B has an additional resonator before the muffler. But my muffler is not exactly in top shape either.

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[Renalicious]

Oddly enough Eric's car did not sound that loud on track. There were other cars with straight pipes, or LOUD mufflers that kept racing with no complaints. Old Chevys, Fords, Mazdas, etc. Maybe it's the whole perceived loudness vs actual loudness?



As for the RS Barn system, I thought it was suppose to be run without a resonator? <img src="/forum/images/smilies/968/huh.gif" class="smilie" alt="" />

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[vnarma]

I haven't measured the sound output of my RSBarn system yet, but I have a slight concern it may be too loud for Limerock, which has very strick sound level requirements. I have the "regular" RSBarn system, with the factory CAT and header. It is certainly much louder, but sweeter in tone. <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />



Anybody know the sound output of the RSBarn system?



Lime Rock's limit is 89 decibels, taken 50 feet directly behind the exhaust outlet! The Glen is 98db, SCCA general is 103db, at 75 feet.

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[Renalicious]

Yikes! Pretty soon they'll start requiring stock mufflers <img src="/forum/images/smilies/968/ohmy.gif" class="smilie" alt="" />

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[flash]

the rs barn system should easily meet those decibel requirements



there is an optional resonator for the system - it knocks down the sound a LOT, but at the expense of a bit of throttle response



the tone, frequency, and pulse has a lot to do with "perceived loudness" - for example, a kid screaming makes me nuts, but i can tolerate loud music at much higher levels - ratty rice grinders make me crazy, but a hot 302 makes me all warm and fuzzy

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[Renalicious]

Thanks Flash, now I'll need even MORE audio samples of the exhaust to know what I'm getting <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" />



From the looks of it I may need to get something with a resonator since Mission raceway (and downtown Vancouver too) are getting pretty strict about sound levels. Mission will tell you to cool it, but you'll end up getting a ticket downtown apparently. As long as the tone / sound / power are still there compared to the non resonated exhaust, I'll be happy <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />



As for the sound levels of the car itself, I've noticed that even with just the airbox mod my car is pretty loud. Even Eric's car I can hear the engine roaring away until he's almost perpendicular to me. Probably something to do with having a large 3L under the hood <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />

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[TheMirror]

pazzer -



How is the noise measured in the UK? Where do they place the db sensor when they measure your car?

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[pazzer]

Hi Mirror, they place the sound pickup about 3 feet from the tailpipe, ask you your maximum revs, which is around 7200, and you have to rev the engine to a certain rpm, in my case it was 5400 rpm's, viola 109db. <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" /> regards Chris. <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />

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[vnarma]

[quote name='pazzer' post='39625' date='Aug 8 2007, 11:16 AM']Hi Mirror, they place the sound pickup about 3 feet from the tailpipe, ask you your maximum revs, which is around 7200, and you have to rev the engine to a certain rpm, in my case it was 5400 rpm's, viola 109db. <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" /> regards Chris. <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />[/quote]

I think just about any exhaust would be "loud" that close to the tip. From a standard distance, what kind of sound level are you seeing, directly inline with the tip??

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[flash]

109 is REALLY loud - the loudest i ever heard on one of these was 104 at 6k at 6' and C weighted

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[Super_Marv]

[quote name='flash' post='39479' date='Aug 6 2007, 04:12 PM']that is pretty danged loud - 109 with what weighting and at what distance?



well, first order of business is to install the cat - that should get you down 5db - it will run better that way anyway - the resonator would take out another 10, but you'll lose some of the throttle snappyness[/quote]



I can confirm that the RS Barn system on Pazzer's car is a good deal louder than mine, and the only difference is that mine has the 300 cell cat - mine has no resonator.



I haven't checked mine to see how loud it is, but I'd say it is below 95db. I'd suspect a Cat would drop the sound levels a bit (5db sounds sensible) so I can't understand why Pazzers is that much louder than mine.



Even though it is really loud, Pazzer's exhaust note is great!! <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" />

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[Renalicious]

How many cells does the RS Barn high flow cat have?

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[Big Dave]

I can DEFINATELY confirm that pazzers system is LOUD.

I followed him for aprox 150 miles the other weekend...You can hear his car for some distance, so just quite what its like in the car, only he + his better half can testify to. ???? Maybee some ear defenders are the order of the day.... <img src="/forum/images/smilies/968/rolleyes.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" />

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[Fox944]

[quote name='Super_Marv' post='39640' date='Aug 8 2007, 04:29 PM']I can confirm that the RS Barn system on Pazzer's car is a good deal louder than mine, and the only difference is that mine has the 300 cell cat - mine has no resonator.



I haven't checked mine to see how loud it is, but I'd say it is below 95db. I'd suspect a Cat would drop the sound levels a bit (5db sounds sensible) so I can't understand why Pazzers is that much louder than mine.



Even though it is really loud, Pazzer's exhaust note is great!! <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" />[/quote]





Having both a Cat As well as a Resonator vs straight pipe will make a big differance in noise levels.



[quote name='Renalicious' post='39650' date='Aug 9 2007, 12:13 AM']How many cells does the RS Barn high flow cat have?[/quote]





300-Cell.

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[frogisland]

Was with pazzer at the time - canconfirm it was 109db, mine was 92db (cargraphic system with 100 cell cat)



The method of measurement pazzer stated is the norm for UK trackdays



JP

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[PJS917]

Pazzers is certainly loud, unlike my gentle restrictive 87db <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" />



Just got a quote today for a full stainless system, 97db max no cat £350.00, I think I shall

be going with it. <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />

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