Is my exhaust illegal?!?!

[CommodoreVS]

I got vs 5.0l and bought it as is with pacemaker extractors, high flow cat and 3" straight from the cat into single pipe. How much db is the legal limit if so what would my reading be? By the way it's manual and when I gear down it makes a loud backfiring sound.. Which creates alot of attention lol Does it affect the sensors? Such as 02 sensor or back pressure? But main concern is will I get a defect?!?!

[GRPABT1]

How long is a piece of string? You're asking people over the net how loud something is. Go get it db tested.

[Grennan]

I would bet my bottom dollar its illegal.

Pretty much any aftermarket exhaust will be illegal on a 304. Id be surprised if its legal with the stock exhaust.

[ari666]

hi-flow cats=illegal. doesnt matter about DB

[joshyewahh]

love those back fire pops n bangs.

id say u'd be over the DB limit. im sure the DB limit is something like85? or close to that.not 100% so dont quote me on that. but im sure your car is over that from whats been done to the exhaust.

[nathanVY]

DB limit won't even come into play yet..

For starters it has to have the same or more amount of mufflers / cats it came with from factory - chances are theres only 1 on it (no resi).
Hi flow cats, will need to be EPA compliant (nightmare..) so have fun with that lol.

Best best is to probably just get your current system flanged at the extractors, and then get a stock system made to fit and flanged at the extractors.
That way if you get an EPA test you can just swap the systems yourself in a few minutes...

Just a thought.

[CommodoreVS]

Yea actually there's no resonator/s on it, just straight pipe from the cat back, causing loud bangs and pops if i want it to. I got a bolt on muffler for the rear which takes 5 mins to swap over the the other pipe. This quietens it that much that u dont even enjoy driving a v8..and yes loses power

[klampy]

iv heard the noise limit it 90db idling and 80db on a drive by.

[ari666]

well you heard wrong. 81DB for all passenger cars made between 1985 and 2005 measured at 3/4's engine speed (so if redline is 8000, then measured at 6000rpm)

linkie for the lazy: http://www.infrastructure.gov.au/roa...gn/pdf/28A.pdf

and blow all that crap out the window. the cops will take one look at the hi-flow and ping you. end of story.

[klampy]

where would that be measured from ari? at the exhaust tip, or a bit away?

edit: never mind, i kept reading.

edit2: if i had the wagon tested, NEP would be about 4800-5200rpm? so 75% of mine would be around 3600-3900. and at that point the exhaust actually quietens down a little, its loud at 2500-3000 and then has a quiet point just over that, and then gets real loud above 4500. i still reckon it would fail tho. lol. just hope i dont get pulled n tested.... never been looked twice at yet...

[nathanVY]

Pretty much any "performance exhaust" won't pass... just depends on the cop .

[Not_An_Abba_Fan]

Firstly I will have to say that not all high flow cats are illegal, Magna Flow do 200 CPSI cats that are EPA approved.

What NathanVS said is pretty much spot on. But it all depends on the cop if you get pulled over, you may be entirely legal, but in his opinion if he thinks something isn't legal he can slap you with a work order and it's up to you to get it inspected and passed. Even if you have a current roadworthy, how does he know you haven't changed something since.

IMO, a 3" straight through off extractors with a high flow cat and no mufflers what so ever is just plain dumb. It sounds like shit and just shouts "look at me". But hey, you must obviously want that.

[GEN3RATD]

But it all depends on the cop if you get pulled over, you may be entirely legal, but in his opinion if he thinks something isn't legal he can slap you with a work order and it's up to you to get it inspected and passed. Even if you have a current roadworthy, how does he know you haven't changed something since.

QFT.

SOOOO many times ive heard "cops wont do anything, i measured it with a ruler and its dead on 100mm" or "nah man, i used my iphone and its just under the legal limit". it all comes down to the cop, and more often then not if you are being a douche he will defect you, no matter what your iphone says.

[CommodoreVS]

I bought as is like i said. The guy before did the exhaust system and it doesn't shit, sounds mad. You gotta be the first person who says it's shit when u haven't even heard it lol. What do u drive drive(abba)?

[GEN3RATD]

I bought as is like i said. The guy before did the exhaust system and it doesn't shit, sounds mad. You gotta be the first person who says it's shit when u haven't even heard it lol. What do u drive drive(abba)?

have a look in his description champ, VTII HSV Senator.

[Jesterarts]

I bought as is like i said. The guy before did the exhaust system and it doesn't shit, sounds mad. You gotta be the first person who says it's shit when u haven't even heard it lol. What do u drive drive(abba)?

What does that have to do with the price of fish? He could drive a nissan micra, doesn't change the fact he knows what you described would sound "average".

Though sound is an objective thing so each to their own I guess.

In regards to it being illegal... yes... yes it would. 5Lt with no mufflers screams "defect me".

Usually I just say "drive it in a way that doesn't attract attention and you should be fine", but in the case of your system... I think idling around would still even draw attention.

My suggestion if you like the current sound and intend on keeping it, have a stock exhaust system in the shed so when you get defected you can simply bolt it on, go over the pits, pass and be on your way.

[JSTCOZ]

Hi-flow cat illegal? load of bs there... -_- .

Anywhooo, mate it'd be illegal and definately too loud. If the system is missing any of the 2 mufflers it is technically illegal. And you dB rating would be well high id imagine (also imagine it sounds tough as rocks :P )

So yes it's illegal, just keep it for as long as you can and stay sensible on the road (y) My V6 is overly loud and i love the sound and so do the people i've shown, just going to keep it for as long as i can until boys in blue pull me up on it, been 8 months so far but i think ive been rather lucky

[Not_An_Abba_Fan]

I've heard my fair share of systems, and you would be in the minority with the rest of your 15 year old mates that think your system sounds "mad". What I drive is irrelevent to this thread. You asked if your system was illegal, I think you got the reaction you were after, go troll some other forum....

[Luke V8]

[undersuspicion]

love your work NAAF

[Dr HaxZaw]

Hi-flow cat illegal? load of bs there... -_- .

ever heard of emission laws??? i have them on my car and i know that if i get defected and they do an emissions check im reasonably screwed... admittedly how you can tell them apart from stock ones from the outside is beyond me but then im not an expert
that and i kept my exhaust quiet cause nothing shouts defect me more than a loud car thats lowered with mags and nice big green P plate on it

[Grennan]

My V6 is overly loud and i love the sound and so do the people i've shown

Wait, wait, wait... Wheres that trolling picture

[JSTCOZ]

Wait, wait, wait... Wheres that trolling picture

LOL! yes yes i know a 6 will never sound like an 8 (sadly waiting until off p's) but I have shown mine to other people face to face and they think it sounds really good and i love driving it with sounds it makes lol

[ari666]

admittedly how you can tell them apart from stock ones from the outside is beyond me

its pretty easy really. you point you laser thermometer at both sides of the cat, if they are both close to the same temperature then you get pinged.

doesnt matter anyway, if a cop wants to ping you he will ping you. one look at shiny cats and he will make it worth his trip to the ground.