R32 Gtr Stock Exhaust Epa Question

[Methor]

Firstly,

Sorry if this is in the wrong section, but there were other exhaust questions, so i thought this would be the place. Also did a search and couldn't find any topics or answers for my question.

So the other day I got a letter from the Vic EPA basically saying that a Police Officer believed my exhaust to be "Too loud" or "Faulty". I had a little bit of a chuckle, but then thought... Okay, it might be blowing a bit of smoke, so I went down, started up the car, let it warm up to running temp and revved it quickly a few times (No smoke) and held the revs at 5K (No smoke). It never occurred to me that it would be the dB rating of my exhaust because my 32 GTR is stock standard, apart from Pod Filters instead of the AirBox.

Feeling confident, I went to get my EPA Compliance certificate as I felt the Officer had just picked on my vehicle because he saw a Skyline and something was loud. Anyway, car failed the EPA test (96dB rating), mechanic thought it was weird as well and checked the Catalytic Converter to see if that had blown out, nope, still intact. He then basically said he could just make up a new rear muffler and exhaust tip to bring it under the 96dB rating.

However, after doing some research I found that the factory exhaust dB rating for a 1990 R32 GTR was indeed 96dB.

My question is this: Has anyone experienced something like this before? Having a stock exhaust that still runs like the day it came out and getting an "EPA Compliance" request. Did you end up changing your exhaust to get below the 90dB rating, or did you just point out the fact that the car came out factory standard with a 96dB rating? If so, how did you go about this?

Kind of like how a Mini Cooper can be defected for being "Too low" but then just showing that factory standard is the low ride height, which is under Vic standards.

I'm going to call the EPA tomorrow and question them on this as well, see what they have to say. But being a Government body, I expect them to be all "90dB is the standard, your car has to be under this... There is no exceptions to what we say, ever.... We are the Government, we know what's right..... lalalalalalalalalalala NOT LISTENING!!!"

[DVS JEZ]

Stoopid Government

[R31Nismoid]

Where did you find it stated it was 96dB?

I find that very hard to believe if i can get a 3.5" exhaust down to 91-92dB.

IIRC a stock GTR exhaust is loud - requires a baffle plate, but it's certainly not 96dB @ 5100rpm

[Methor]

My bad, sorry... It was 94dB @ 5100rpm, so in 21 years my exhaust has gained 2dB. But still came out factory spec over the 90dB rating.

[Johnny]

Thats very interesting, i had one of these exhaust tests 'requested'

I have an r34 gtr with a kakimoto exhuast and high flow cat, i replaced the cat with the oem unit and got it tested - result was 87dB @ 5000rpm which was a surprise to me and the a@@hole testing guy who retested it 3 times with his disappointed face that he couldnt make any money off me.

A stock exhuast with cat making 96dB is very loud; did he do it in a wide open area so the echo dosent affect the result?

[boostn0199]

Im also finding it hard to believe standard exhust 96 db as that is hell of alot louder than 90 ,96 would b about what most aftermarket jap exhuusts are. I would think that your mufflers in the system have probably given up.

[saliya]

Feeling confident, I went to get my EPA Compliance certificate as I felt the Officer had just picked on my vehicle because he saw a Skyline and something was loud. Anyway, car failed the EPA test (96dB rating), mechanic thought it was weird as well and checked the Catalytic Converter to see if that had blown out, nope, still intact. He then basically said he could just make up a new rear muffler and exhaust tip to bring it under the 96dB rating.

I still have the stock exhaust from my 93 v.spec; I had it measured when it was on and IIRC it was 87.something dB at 4800RPM.

There's a massive difference in audible sound level between 88dB and 96dB - maybe your mufflers have packed it in?

Was your test administered by the EPA or by the mechanic? If mechanic, visit another and get a test. Reason:

* dB meters can go out of calibration (most exhaust places don't calibrate; the EPA is supposed to)

* the test has to be administered a certain way (many exhaust places don't know the method, it's in the ADR)

* there is a temperature correction (IIRC, for temps different to 25 degrees). It is very cold now; low temperatures == louder, most exhaust places won't correct.

* there is a frequency weighting curve (don't know whether meters apply this automatically or not).

I'm going to call the EPA tomorrow and question them on this as well, see what they have to say. But being a Government body, I expect them to be all "90dB is the standard, your car has to be under this... There is no exceptions to what we say, ever.... We are the Government, we know what's right..... lalalalalalalalalalala NOT LISTENING!!!"

Don't really know. I don't think that 94dB is what a stock 90 GTR came out at; but since I don't have one of those I can't tell.

Since it's post 1989 (Motor Vehicle Standards Act) you'd think that it would have had to comply with whatever the emissions requirements were at the time.

You need to find out which ADR your car needs to be compliant with.

If it was Aust-delivered or imported pre-1992 that would probably be ADR28/00 (93dB max limit, 92dB stated but within 1dB is compliant, drive-by test).

If 1992-2005 might be ADR28/01 (91dB max limit, similarly 90dB stated but within 1dB is compliant, stationary and drive-by tests)

http://www.fordforums.com.au/vbportal/modules.php?name=Content&file=viewcategory&cid=18.

has what looks to be the originals of many ADRs

Cheers,

SW

[R31Nismoid]

Far as i could gather he's not actually got any information to prove 96dB factory, and there is no way a stock GTR was ever 96dB anyhow. He is going off some thread started by someone here that is just plain wrong/misleading.

[StreetR32]

I just got done by the Highway Patrol who notified the EPA of my aftermarket exhaust, as a result I had to visit CARLINE in mayfield who made me a new exhaust - just passed at 89db. Other silly fact is that I had to supply proof that the car is not fitted with a check engine light. Now I need to find a way to get my kakimoto race system under 90db...

[DVS JEZ]

Why do u have to prove u Dont have a check engine light?

[StreetR32]

Guilty until proven innocent.. I guess some GTRs come out with a check light?

[DVS JEZ]

All cars have a check engine light. Whts there point tho???

[GTR_NUTZ]

Got done twice for loud exhaust. First time it was 90db on idle and 107db at 5000rmp. The muffler dude said he'd change it to a 2" from cat back and then wrote down 89db on the slip. I kept the new exhaust for future issues and to my luck it payed off a few months ago and I just swapped it back and got it tested but i told the muffler dude he made this one for me and passed it as 89db. The muffler dude then tested it, I was looking over his shoulder to see the db reading but he hid from me.

Your check engine light won't come on with just a turn of your keys to accessories, it'll flicker a few times when you're driving it hard and something has gone kaput or warning you of something will go kaput soon. ie bad knock or afm max voltage....

[StreetR32]

All cars have a engine check light - wtf? Name a carbs car with a engine check light? Some R32 GTR's don't have them - go find it I the manual!

[DVS JEZ]

The cat light doubles as a check engine light.

GTR NUTZ- the flickering of a check engine light due to knock etc is only with power fc's.

Also ur being stupid saying about carby cars, we arent talking about carby cars, all cars loosely meaning.

[fatz]

Stock gtr is about 92 db