db for exhaust
 

where is perth can i get the db reading for my exhaust ?
just in case the boys in blue pull me over

At the pits. I had the db reading written down on my permit for the exhaust too, alongside the max legal limit.

on this subject what is the db limit for an exhaust in perth :confused:

Without trudging through the VSR's online, I believe the legal limit to be 90dB for cars... higher for bikes, trucks etc.

yer 90db is correct. when i had my mazda turbo the boys in blue told me it sounded too loud, so i went to the pits and they tested it and i got 35db.. a long way off illegal... good to get a permit tho..

If you take your car into the "pits" for an exhaust db reading, and it comes back higher than legal, are there any issues? ie. are they going to sticker you right there?

Permits are just get tested, pay money (approx $35 ??), get piece of paper and drive away huh?

how do they test the db? Ne1 had this done b4. Like wat meter how far do they put the mic from the zorst. Is it free air or do they do it in a room?

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Many statutory bodies around the world currently mandate that vehicles comply with stationary exhaust noise tests specifications - Generally based upon the "SAE J1169 Measurement of Light Vehicle Exhaust Sound Level under Stationary Conditions"[/font] [font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]For example, California and various other states in the US mandate J1169 SAE stationary noise tests. In Australia the test requirements are ADR 28/01 stationary noise test and it too is based upon SAE J1169. In fact, the above tests have identical test procedures and only the required limit varies:[/font]

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]The test involves positioning a type 1, SIA compliant ANSI S1.4 - 1983 noise level meter, specifically as illustrated in the diagram below. No other positioning is relevant! Noise tests are extremely specific in their scope and must be conducted very carefully![/font]

[img]http://www.airpowersystems.com.au/us_spec/subaru/exhausts/noise_test.gif[/img]
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[/font]
[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Engine RPM must be held steady at 75% of rated peak horsepower RPM.[/font]

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Given the latter figure is 6,000 RPM for the [b]US spec.
WRX/STI[/b], the test speed is [b]4,500 RPM[/b] for these vehicles.[/font]

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Again, it must be emphasised, all facets of a noise test must be specifically followed for the test to have any meaning.
[/font]

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All info stolen from : [url="http://www.airpowersystems.com.au"]http://www.airpowersystems.com.au[/url]
Dunno if it is still current,,,
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DB limit actually varies from car to car, the guy at Welshpool showed me this very thick book of DB limits for various cars. Now this was 3+ years ago, I can't remember but I think the DB limit for a 99/00 WRX was 91 DB.

91/92db sounds correct. Last time i was given the test at Warwick pits i was tested from about 1-2m away at 1,500rpm, 2,500rpm and 3,000rpm (supposed to be 3,500rpm but no one was watching so i didnt go that high!)

Over 2.5K rpm my car was illegal (102db) and i was told that "given you have no cat, i'd suggest you keep it under 2.5k so we dont see you again" :D I have a DB meter on my phone (how accurate it is, i dont know) but the new exhaust is much louder...