How loud are you?

[Guest]

Got my cert today... 88.23dB down from 97.78dB... with the addition of one resinator in the midsection.

SYMS stainless tuned length extractors, 3" dump pipe, 3" midsection to a Fujitsubo Superlegalis muffler with 4.5" tip.

Who else has been tested?

[Guest DVNT]

Failed Wof on 102db worked out guy tested it inside, retested outside at 92db ;D

standard pipe all the way back to sports muffer on rear.

[ReubenH]

I tested myself and scraped in at 94.5 dB. I thought it'd be allot quieter when i went to go buy an "HKS Silent high power". Guess not. The zaust is a rage 3" downpipe and midpipe, with the HKS muffler.

Recently failed a wof cause the muppets played the "it's louder than factory" card. Fair enough i guess though, since they didn't have testing equipment, got it sorted in the end.

[spark_38]

welli need to organize a dB exhaust day... quite a few of us here have reasonable exhausts which would sh!t on the 95dB mark... i have no idea how quiet/loud mine is - maybe 95.2dB at a guess

[QIK_KAS]

Mine is 94dB, and has a 3" all the way back and a sports muffler.

It's to damn loud, and I can't sneak anywhere without people hearing me. haha

[Scoobydoo]

Mine was 97dB with a twin turbo system... I havent had it tested since i single turb'd it but it wouldn't be any quieter im sure

[Joker]

think I wqent down from 107 to just under 90 i miss it - keltik hows my CANNON working for you!

[Mutsuraboshi]

 JoKer said:

think I wqent down from 107 to just under 90 i miss it - keltik hows my CANNON working for you!

+1

Was sitting at around 107 but now down to about the 90 mark as well.

[Guest]

;D - I'm loving the quiet aye... it's rowdy with the external when you get it cranking, but whisper quiet if you're cruising around doing 50k at like 3am.

[BC5RA]

108.9

[GC8E2DD]

What sort of volume would say (for instance) a stock STi Impreza exhaust generate? Just for reference ...

[THUNDA]

127.4

Custom exhaust off turbo the pokes out the side behind the passenger side front wheel

(is only about 1 metre long, completely free flow)

[Joker]

 GC8E2DD said:

What sort of volume would say (for instance) a stock STi Impreza exhaust generate? Just for reference ...

Stock BH legacy is under 90

I think you will find any Jap import is the same from factory

[Guest SPANKU]

132.8db!!!

[QRAF]

every 3db you go up you have doubled the sound or volume. I'm sure someone will correct me so there is a huge difference between 91db and 94db just thought i'd make you all aware of this.

I'd be interested to see how loud mine is, how much does it cost to get tested?

[Joker]

if you know a guy - free - $35 for quick check where I go

It pays to ask, most WOF's testers have a meter now BUT only a few are certified to issue a plaque to say you are legal

[GC8E2DD]

 QRAF said:

every 3db you go up you have doubled the sound or volume.

It isn't linear like that, but yeah it gets big fast. I'm impressed by Hopai getting around the volume of a stock BH legacy with a 3" setup right through! I currently have a 3" cat back which came on the car. Was wondering what to do with the rest. Maybe now I wonder no more =]

[Koom]

 GC8E2DD']

[quote name='QRAF said:

every 3db you go up you have doubled the sound or volume./quote]

It isn't linear like that, but yeah it gets big fast.

It is how he explained cause that ain't a linear relationship i.e. go another ~3 dB up and its quadruple its original value. Go another ~3dB up and its octupled (is that even a word?? 8x) its original value.

It works on a logarithmic scale

[Guest]

Hehehe, my stupid neighbours complained about the noise of mine starting up in the morning.

Strangely, I don't think my car is any louder then theirs, it is just a lower rumble! You can barely hear my exhaust in the car with the windows up so to get a nice subbie rumble you have to roll the window down.

I took it in for a warrant yesterday at the Kingsland VTNZ and deliberately hung around outside as I haven't heard it from the outside but I couldn't hear it over all the other noise around so mine must be pretty quiet.

It is stock except for a Ground Dynamics exhaust section with a 4 inch tip from the diff back.

[cpt kernow]

I've got a certified sound meter for work- I test fire alarms. I'll bring along to the meet at westgate if anyones interested.

What are the rules? is it something like 1m away at 3000rpm?

[G-unit]

4000rpm for 4cylanders

mine is 91.6 without silencer in ;D

[Guest]

 cpt kernow said:

I've got a certified sound meter for work- I test fire alarms. I'll bring along to the meet at westgate if anyones interested.

What are the rules? is it something like 1m away at 3000rpm?

http://www.lvvta.org.nz/stdExhaustNoiseEmissions.pdf <-- that's the manual that the testers use for testing.

or to sum up your question...

 

Microphone set-up and positioning

2.8(3)

The sound level meter microphone, when testing a low volume vehicle for exhaust noise emissions, in all cases, including those specified in 2.8(4) to 2.8(8), must:

(a) be protected by a foam wind-shield at all times during the noise emission test set-up and testing process; and

(b) be positioned at: (see diagrams 2.1 and 2.2)

(i) a distance from the exhaust outlet of 500 mm (+/- 10 mm), except where the vehicle meets the criteria specified in 2.8(7); and

(ii) an angle of 45 degrees (+/- 5 degrees) to the direction of gas flow, always using the position furthest from the vehicle’s longitudinal centreline; and

(iii) the same height as the exhaust outlet, however not closer to the ground than 200 mm.

[Guest lan_killa]

Im not sure on exact readings on my cars... but what I do know is that my 998cc Mini was loud enough to acquire a green sticker and get me a $50/25 Demerit fine

[subieboy]

Sheesh I saw this thread and my mind instantly headed ***somewhere else***

Anyways my muffler was tested and got in below stock (back in 2005 now and cant remember what Db level now)

[pixel-pimp]

some of us Dunnerz guys did ours last year. I bumped in at a massive 84.8 dB haha, and thats stock with a 4 inch tip.