exhaust noise finale

[ke_25]

will dumpys make it quietr or louder since they face the ground? or wil it make minimal difference?

[Truenotch]

apparently the origional reason for dumpys was to point the sound down to minimise it, although with 4 - 5 inches of hole it probably doesn't matter.

[the fallen303]

old muffler used to be quiet on the jz, but then when running 16psi and redline, it used to scream like an external, was kinda wierd...

[Dell'Orto]

How can they abuse it?

What we are talking about is stopping the annoying people racing around at night annoying others.

To abuse it, they sit there, and pick every single car that looks like its modified, and then do their thang, then that person has to pay to go get it tested somewhere else, its not like they test it on the spot, sweet, sticker, it can easily be abused. Where does the fee go to, and can they still pinky us when they decide it needs to be tested, and will they give us a fine anywhos? Theres no sticker that says it is too loud and its illegal, so no sticker still should give the benefit of the doubt?

im confuse

No, once you've got the sticker, the papertrail is quite comprehensive...we're talking diagrams and photos of the system. So theoretically if you get pulled up and pinkied with the sticker on, you could go to court and take them to the cleaners.
Chelles, I agree with you on the induction noise...some chap in a Honda went past last night, all I could hear was the boooOOOOOOOOOO as it went past, so I can imagine the aussie law on intakes becoming law here:? Cant see how they can nail BOV's though, they arent that loud

[slighty_sykotic]

BOV are letting air out from the engine that doesnt go through a proper system, like a cat and muffler system, ie, its a emmission reasons that they don't allow the bovs venting in Aussie...


And a side note, my car "bov" sound is frekin loud.... like really loud. On my car is just the massive amount of compressed air being forced back through the spinning compressor blades.

Anyone that has heard it in around town (with buildings) will agree with how loud it is. Sound like a SSQ on high.

--Sykotic

[Dell'Orto]

BOV are letting air out from the engine that doesnt go through a proper system, like a cat and muffler system, ie, its a emmission reasons that they don't allow the bovs venting in Aussie...

Yeah, but the issue of them causing extra emissions has been proved BS on more than one occasion.

[wde_bdy]

BOV are letting air out from the engine that doesnt go through a proper system, like a cat and muffler system, ie, its a emmission reasons that they don't allow the bovs venting in Aussie...

Yeah, but the issue of them causing extra emissions has been proved BS on more than one occasion.

Basically any factory turbo system will have a PCV hooked into the intake pre turbo, so when you vent your BOV you are also venting crankcase fumes. Not to mention causing AFM cars to run rich, so it definitely does cause emissions problems.

Callum

[Dell'Orto]

Basically any factory turbo system will have a PCV hooked into the intake pre turbo, so when you vent your BOV you are also venting crankcase fumes. Not to mention causing AFM cars to run rich, so it definitely does cause emissions problems.

Callum

A few of the companies did tests (albeit it on non AFM vehicles) and the increase was neglible.

[MR2SIK]

I did some highly scientrific tests with the bov in my car, factory plumb back, very quiet and no noticable change in afr. have it venting and i can see the flames from my exhaust from my rear view mirrors im sure that theres more emissions from my car that way...

[wde_bdy]

A few of the companies did tests (albeit it on non AFM vehicles) and the increase was neglible.

An increase is an increase though. The arguement is (not saying I agree with it) that emissions systems are designed effectively for the life of the vehicle. Testing on a new car with minimal blowby will give very differnt results to an older car with increased blowby. Same as with cars with vented cach cans, particular engines or more worn motors give noticable fuming compared to others.
They key point is manufacturers pay big $$$'s to prove their cars meet the requirements, not many aftermarket suppliers are willing to pay for independent testing to prove their product will meet the same requirements especially it will require a different test for each car type. In the US though the volumes are big enough to justify it, in California CARB certification is very common to see attached to model specific performance parts.
The government quite rightly looks at it and say if you want to mod your car PROVE its still has legal emissions.

Callum

[slighty_sykotic]

I didnt say that it was or was not BS. I was just stating how a bov is illegal in aussie, its not a noise thing, its a emmisions.

--Sykotic

[Stealer Of Souls]

Doesn't Oz have a dB limit of 85?

[BZG - Luke]

Took my Levin in to get a WOF on saturday at VTNZ.. as soon as I turned the car on the old bastards eyes lit up.. he hopped in and gave it a couple hard revs up to 7 grand and failed me for noise. Then had a good look at the tinted windows and body kit which are fine.

Time to get a resonator or something fitted and hope that it does the trick. I bought the car with the current exhaust already on it and its passed previous warrants.
(I actually wouldn't mind it being a bit quiter anyways.)

It would be interesting to know what the DB is at a constant 4800rpm at the measured distance.. but I dont want to have to pay for the test and fail.

[86_rolla]

7 grand are you sure? if he revved my car that high id be tempted to crack him one.

[flygt4]

first mistake was going to vtnz it pays to have a mechanic that you take your car to often and wont make an issue out of it.

[ShOC4UGTT]

I'm a bit at a loss as I've just had my manafold repaired and was concerned with my muffler noise as I have a blitz muffler and full pipe set up and in my mind it's not quiet by any means but at magoo mufflers they told me not to worry about the W.O.F so if I don't get one there is no way I'm paying $150 for a test as Magoo should of of done this when my car was in the shop!!!!!!!!!
I'll keep you posted!

[XSVWGN]

I think the law is a good idea and it is because of shupid hoodlums racing up and down areas they shouldnt and ruining the scene for everyone and anyone. I must say that my wagon loud and VTNZ tried failing me for it in the past but i told them to get F%^&ed as it was in their shop and echoes like hell and is next too train tracks!!! idiots!

I know that my old mans harley was measured at 126.4db last month at Paraparaumu airport!!! and that has slightly bigger than standard pipes on it ...but is is a 104 cubic inch engine haha

[RomanV]

Chelles, I agree with you on the induction noise...some chap in a Honda went past last night, all I could hear was the boooOOOOOOOOOO as it went past,

Oh, that's me exactly. (sounds better than a honda though )

On my MR2 I'm running a standard exhaust + cat. No way they can fail me on that.

However I've got an aluminium pipe with a fricken huge apexi pod filter on the end, and it's REALLY loud when you've got your foot up it.

No problems with WOF, but it could probably be classed as an 'annoyingly' loud car, if I went fanging it around past peoples houses late at night.

I dont actually do that however, for the sake of not wanting to piss people off.

I'm not sure how I'd go in a DB test, seeing as how the pod filter is in the rear of the car, near the exhaust.

[slighty_sykotic]

You should be ok, cause its not going to be comming on boost hard while being held at a certain rpm, so the induction noise should be ok.

Should be..

--Sykotic

[Silent Knight]

You should be ok, cause its not going to be comming on boost hard while being held at a certain rpm, so the induction noise should be ok.

Should be..

--Sykotic

He don't have any boost...