Golgo fails EPA noise test with flying colours!

[skylineakt]

Hey James,

I got a standard cat-back R33 GTR exhaust.

It came with my car even tho it is a GTST. The guy said the only difference between the two is the muffler.

Just to be sure with the muffler, does the standard GTST muffler has the same tips as the Oz S14??

Well if you need to borrow it give me a pm.

[PranK]

heh.. 97 eh?

girly..... mine cleared 100....

you can borrow mine if you want??

[Jamezilla]

Haha - Prank

I'll get him to check it with my 'special' cat back in and see how much louder it is.

Thanks all for the help. Ice have a 33 GTST system there that I will fit up. The tester is just around the corner - so no biggie.

Ghostrider: That's a really good idea. I think it would be something worth while for these sorts of things for everyone to chip in a few $$ to make up a quiet system for all the shapes/sizes of exhuasts we need - for such occasions.

The tester agreed that it's all a bit silly. Testing my car at 5400 rpm - of course it's going to be loud! Most of the time around town I never get above 4000 - at which it was 85db.

Ah well - all part of the game I guess.

Thanks all again for your help

[Ghostrider]

Haha - Prank

I'll get him to check it with my 'special' cat back in and see how much louder it is.

Thanks all for the help. Ice have a 33 GTST system there that I will fit up. The tester is just around the corner - so no biggie.

Ghostrider: That's a really good idea. I think it would be something worth while for these sorts of things for everyone to chip in a few $$ to make up a quiet system for all the shapes/sizes of exhuasts we need - for such occasions.

The tester agreed that it's all a bit silly. Testing my car at 5400 rpm - of course it's going to be loud! Most of the time around town I never get above 4000 - at which it was 85db.

Ah well - all part of the game I guess.

Thanks all again for your help

hahahahahahaha, typical motor transport bullsh#t, they really have no idea do they.

If you didn't go over 4000 around town, I'm not surprised, if you still got stock diff ratio 4.1, you could cruise around at 60k in 2nd, about 90 in 3rd, over 110 in 4th, and over 150 in 5th. Little do they know we will be cruising at under 2500 and exceeding the 60k limit in top gear (4th).

Be nice to be able to jam specs in their face, just to show how stupid they are. :ghost:

[Jamezilla]

FYI: This is where they put the microphone.

[meshmesh]

james,

did you ask them how they deterimen what rpm to rev your car at?? 1.. that seems way too high & 2... rpm levels seem so inconsistent eg: one guy in st albans rev to ~3800 another revs em to 5000?? WTF :confused:

[Ghostrider]

That's about right, all but for the RPM.

Our test here in NSW to comply with ADR 27A is:

Microphone Position: @ 45 degrees & 500mm outboard, @ 280mm high @ 3500 rpm or 75% of max power.

[Ghostrider]

James,

What does an R33 RED LINE AT???

Take 75% of that and there should be the rev limit for testing.

My HR30 Tacho red lines at 7000, in 9000, but it's for the FJ20 DET 4 cylinder.

Even so! 75% of 7 G's is only 5250, but didn't you say you had to go to 5400, that makes your red line 7200. From factory, it wouldn't be that high, SURELY?????

[Guest INASNT]

james,

did you ask them how they deterimen what rpm to rev your car at?? 1.. that seems way too high & 2... rpm levels seem so inconsistent eg: one guy in st albans rev to ~3800 another revs em to 5000?? WTF :confused:

They tested my car at 5400rpm also. If you go to a exhaust shop for just a certificate then they just test it to 4000rpm or so but epa tests it alot higher.

James how could you fail seriously??? didnt u test the system with a db reader before the main test?

[meshmesh]

James,  

What does an R33 RED LINE AT???

Take 75% of that and there should be the rev limit for testing.

My HR30 Tacho red lines at 7000, in 9000, but it's for the FJ20 DET 4 cylinder.

Even so! 75% of 7 G's is only 5250, but didn't you say you had to go to 5400, that makes your red line 7200. From factory, it wouldn't be that high, SURELY?????

That's intersting, I dont have the original GTR dash, but on my nismo, redline is at 9000rpm, & the yellow "redline is at 8000rpm"...

do they go by the dash?? or the factory specs?

[Ghostrider]

Just got the good guts JAMES.

Position of mic is 45 degrees @ 500mm (1/2 metre) level with the exhaust outlet

Stationary engine revs 75% of MAX POWER DELIVERy.

This means, NOT REDLINE, but factory specs, max HP @ ???? rpm.

75% of the max power limit.

GO STICK THAT IN THEM, you might not have to change your system at all. My engineer is suggesting about 4 g's would be the max rpm required.

Just a suggestion, Go see the ENGINEER that did the bus when it was imported, it would have had to comply for COMPLIANCE.

[Ghostrider]

AND by the way, 90db is the go!

[Snowman]

Factory specs on GT-R's are rated at 280hp@6,800 rpm - which means 75% = 5,100rpm. (Not that far from where James was tested) I dont think dropping from 5,400 to 5,100 would decrease the noise level from 98db to 90db so some changes would still be needed.

[Jamezilla]

The tester had a book with him - looked up RB26DETT and came up with 5400rpm (or there abouts)

INASNT: Yeah... that would have been the smart thing to do

[AutoTrust]

Go back without the cat and melt the microphone!!! Bet he would charge you then!!

If i was in your position i would get a swirl flow resonator that doesn't restrict air flow but forces the exhaust gas against the walls of the resonator to reduce the emmitted noise.

I have an apexi ECV which suits me for the moment, Although i am sure that my car is under 91db it is very droney at cruise and can resonate through the house at idle. The ECV is very handy for remote start in the morning and driving past white cars with blue stickers... oh and for phone calls too!! It is not the ideal solution for a loud exhaust due to its slight restriction but makes good for stealth mode.

[Guest RedLineGTR]

You know that neither one of those suggestions are not legal as far as the epa goes.

If i was in your position i would make a restrictor plate and fit it behind the cat, leaving a 2 inch hole in the center, this would create enough turbulance to shut it up and you could re fit it in 5 min if you needed.

i would not post that up i dont need any newbies getting diKed and doing the sam..if more and more people start doing it they will be checking it more and more accurately. I'm sure james know about. Can u delete the post if now then i will in time. I hope u know what i mean *i will delete mine too.

[THE OAK]

97 ish db , didnt even bother going to 4800 rpm, i was abit shocked .....oh well another one bites the dust!

time for new zorst

[jetgts]

I had to get my gtst tested so i put on a standard exhaust

and it just passed at 90db! totally standard!? My previous cat back

was tested at 98db - oh well it passed