Aftermarket Exhaust and New Rules

[What?]

CK is right - a petition is worthless unless you have got over 150,000 signatures on it, and even then may not be worth the paper it is written on. But a few hundred submissions is a lot of noise, especially when copied to your local MP and any other relevant MP's.

And if you get a pull for noisy exhaust, go to court to defend it. The more cases that get thrown out, the better the odds of the proposed rules getting thrown out. Even a Hogly with straight pipes could be defended if you could produce noise meter evidence of said Hogly versus a V8 Cat with jacobs brakes on full.

[Coldkiwi]

I think some dickhead plod must've decided that 'close is good enough' and that when the draft rule came out, it was therefore enforcable and proceeded to tell all and sundry (ie the politicians) that they had a wonder solution and 'show the media how wonderful we are'... without realising the usual legislation rigmorole (sp?) that it has to go through. Now all the piggies (including our local plod in Howick/pakuranga, according to his spurt in the local paper) think they can go dishing out fines willy nilly and are getting wasted when people fight them.

it really is a 3rd world country sometimes....

[Marmoot]

CK: worse.....it's not a 3rd world country, but it is GOING DOWN to 3rd world country. That's worse than anything.....

[cranker]

Hey Guys, just for everyone's info in terms of noise testing there is NO, I repeat NO facility either here or in Australia that can test dB levels to a given Standard, all of that sort of stuff comes under design rules of original manufacturer. To the best of my knowledge the only facility able to test is in Europe whih is where manufacters go to test their vehicles for that reason.

To set that sort of facilty up here is in the region of billions of dollars- even australia doesn't have one.

Because db levels have to be measured relative to a standard the standard has to be a fixed value. the only true fixed value is an anechoic chamber & a sealed one at that. If you test in open air you come up against relative air density density and proximity variables as well as air temperature variables all of these values are constantly changing so there can be be no standard. also background noise comes into play as well.

[Motu]

It's all muddy water as far as I'm concerned,so everything is invalid.My exhaust supplier says all their NZ made systems comply with blah,blah,blah at so many decibels - that's nice,but what have they got making the noise? a sidevalve Dodge with 5:1 compression or or a high comp engine with a radical cam? what goes in effects what comes out.

You are right,there is no way we can replicate the compliance test,so just bin the whole rule.

[Jackrat]

I don,t know about anybody else but the nice man that I get my warrants from don,t even ask me to start the bike,he sees bike a half dozen times a week anyway.He also gives my brother warrants for his stroked an poked hog that would wake the dead
so who bloody knows aye!!.Some times it,s good being a hay seed .

[Coldkiwi]

I dunno about that testing facility. You don't actually need a certain building or anything, just the measuring equipment (two microphones, a few laser trip sensors, a little datalogger on the vehicle and some processing equipment you could easily buy or hire in) and a nice quiet old airfield or closed road. Its not really rocket science, just requires a bit of setting up (I read the standard for measuring).

I'm not surprised there's no dedicated test facility in Australasia because it would only be used by manufacturers releasing new vehicles. I'd say there will be a couple in Japan, America, at least one in Britain and a few in Europe.

Motu, I'd say most suppliers doesn't know what they're on about. You're on the money about those systems normally done with a ceertian car and the manufacturers standard system. You can bet your backside that most exhaust suppliers don't get a ISO362 standard compliant test done when they release a new system for a particular machine. After all, half the reason people put new systems on is to make them louder and I'd doubt whether a louder system would pass because the average bike/car manufacturere isn't going to plug up their machine more than is needed to pass the reg's.

having said that... my Zx-6 is friggen quiet compared to the GSXR!

[cranker]

The previous thread I sent re db testing levels I sent comes from a person who is involved directly with noise level standard ie he is responsible for new Truck compliancing for a New Zealand New Truck Importer/distributer. Truck Standards are much tougher than cars or bikes.

Coldkiwi, the things you mention in your thread are exactly what causes spurous readings, why? because you can't test in an open air environment to get an acuurate reading because of the reasons mentioned in my previous thread- air is varying in temp, air density and presuure constantly.in fact if you did a noise level test with equipment all set up outside and did two level tests 15minutes apart the two individual tests would have different readings, also standing wave reflections affect tests- bottom line is that if you get halled up for noise even by your local council from a stereo., in court they have to proove that they tested to a standard, they can't test to a standard because there is no standard achievable

[Coldkiwi]

Cheers for the points cranker, but fret not. The ISO 362 standard is as anally retentive beyond belief. The acoustic consultants and people submitting to it must've argued for years and I can assure you all of those factors are VERY well covered. There are strict limits on background noise, areas of tarmac, air temperatures/ humidity/ nearby obstacles and you have to get within 2db for each run or throw the result out... and then get 4 readings within those 2 db... twice (because you have to run the vehicle the other way too). I copied all the juicy bits down at the library when putting my submission in to LTSA but really wished I was allowed to copy it because of the plethora of information.
The standard isn't impractical from a manufacturers point of view if you're only talking about small volumes of vehicles; in fact I'd say its really good because its thorough and as accurate as it needs to be to assess exhaust noise. The only downside is that its not quick and easy to put a large volume of cars through and hence not suitable for every car on our roads.What I think is needed is a similarly set up test that is far less thorough but is coupled to limits with sensible tolerances and limits to take inaccuracies into account.

btw, I'm curious how you get a standing wave formed in an outdoor environment. mmm yes :confused2:

also confused as to where you'd spend billions of dollars to set one up. I know Bruel and Kjaer equipment isn't cheap but its not that bloody bad! I think I could build a nice B&K equipped anechoic stadium for that sort of wedge.



 

[cranker]

OOps coldkiwi .. er standing wave, I actually meant reflected wave sorry, as you would know from your acoustic eng background standing wave occurs inside a building not outside,

Haven't read the standard, but last post you sent probably re latest in Iso at least seem to recognise that there needs to be some give & take

Re the problem of air density and background noise, Our man down here with the wind generater has just been shut down because he can't come within noise limits at night and yet he can meet them during the day , just goes to show what cool air at night does for noise!

Had the same problem exactly years ago when noise limits were envoked at Western Springs, I was riding solos there when it came in axactly the same thing happened between afternoon & early evening readings.

Hey by the way good to see a Howickian on the board- i'm an ex-pat one myself, born & bred there actually

[Coldkiwi]

at a guess I'd say your turbine mans problems were not the air temperature but rather that different noise limits are introduced during the night time (as appointed by territorial authority in all areas, farm/city/suburbs/industrial etc.) I wouldn't think the air temperature is going to make too much difference although there is an effect that can cause reductions/fluctuation on hot or cold days over long distances (but not the 7.5 called up in ISO 362).