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Which Exhausts Systems Are Epa Legal

xm4tr1x

By xm4tr1x,
in Victoria

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xm4tr1x Enthusiast

xm4tr1x

Posted
Posted

Hi Everyone, there seems to a lot of EPA slips flying around and landing on windscreens and in letter boxes.

Question is which exhausts have passed and which haven't ?

There is plenty of different setups when it comes to exhaust and of course depending on whats done to the engine does have a huge impact towards the configuration of the exhaust setup,

So post which mods you have and exhaust configuration including the Db reading for each setup.

Example:

BMC filter

FMIC

EBC

PFC

split dumps > 3" down > 100cpi cat > 3" > resy > HKS HI power muffler

102 Db

running 210RWKW

All else stock.

Takahashi GTR Rising Star

Takahashi GTR

Posted
Posted

I had a Kakimoto catback, 2 large oval mufflers and a standard cat, no chance it would have passed EPA, stock is really your only option on Skylines.

Stock GTR's are over 90 from factory, we are all F#$%#*.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

and I thought my 3.5 inch racepace full exhaust was quiet...until it's opened up at 8k

My RP 3.5" (on the 31) is 91-92dB @ 5100rpm. So juuust about legal, but not quite.

Not sure if the GTR version was able to have larger mufflers to get it down further.

Either way enough to have a nice note, but not get attention :)

Takahashi GTR Rising Star

Takahashi GTR

Posted
Posted

Well if it's over 90 from factory doesn't it make it legal because it's been complied?

There is a cut off date for the exemption, for instance a 67 Mustang can be 114db and get away with it, just not sure on the exact date.

emts Grand Master

emts

Posted
Posted

There is a cut off date for the exemption, for instance a 67 Mustang can be 114db and get away with it, just not sure on the exact date.

I wish.....

older than I think it 85 are the older ADR's so we get 94db but that it.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Not to a legal standard whilst maintaining the flow of a straight 3.5" exhaust, decent CAT and acceptable ride height etc etc - on a skyline.

People including myself have been there and tried, you come close, but just not enough.

Another car with a different floor pan, then possible if you could get mufflers on there that are larger again... But 2-3dB is actually a substantial amount of noise to soften.

It's the noise of the motor and the 4700/5100 RPM that the tests are done at that sets the meter off. They also measure "back off" noise too, which often a crack/pop will set the meter off over the limit.

3" you can get passed however, as i said in post #4

xm4tr1x Enthusiast

xm4tr1x

Posted
  • Author
Posted

So which 3" configuration do know you of that can pass

which dumps, down, cat, res, muff, material, press, brand etc.

The big question that follows is do you have evidence?

vspecIInur Experienced

vspecIInur

Posted
Posted

I just find it hard to believe that a stock exhaust system on an R is >90db or is that referring to a particular model - 32, 33 or 34.

The standard 34R system seems pretty restricted to me however, the only good thing about it is the awesome flow properties from the manifold and dumps. Do not change them :)

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