exhaust noise and the police

[goosie208]

hey pistonheaders!
right!! so i was driving into town on Satuerday night and came came accros and was stopped at a Garda (police) checkpoint, i drive a fresh import JDM Legacy B4 twin turbo. from what i can tell it has the standard backbox exhaust etc (about 3or 4 inch diamiter i spose) .. the officer said it is "stupendously loud" and that i HAS!! to be changed.. i then proceded to tell him its the standard parts and stuff but he still insisted thet it dont conform to Irish requirements..

my question is this,.... putting on a micky mouse, small bore, high resistance, rubbish backbox that the Irish exahuast centres only seem to stock, will this cause any engine problems? turbo problems? at the very least, a serious lack of power!! from the lack of breathability, seen as turbos run on exhaust flow and if its restricted it must slow the spooling down??? im not amazing on cars so i would love some feedback form so dydes that know the shizzle!!

thanks lads!!

[dnb]

What is the noise level you have to aim for? Grey imports in the UK that were SVA tested had to be less than 102dB. Anything under this is OK and legal here, no matter what the police like to think.
If the vehicle was type approved then it's something like 89dB.

Check the law carefully.

BTW, if you want something quieter then there are other options in the UK - eg I hear that Revolution systems are reasonably quiet and flow well. (No experience myself - I have a full Hayward & Scott system on mine)

[goosie208]

hey thanks for your help man! the funny thing is.. at the moment anyway there actually isnt a set "law" as to the Db your exhaust can be.. its actually down to that particualar policemans descresion!! so i dont really know what to aim for.. as if i get the same guy next time he'll be like " yeah thats better" but anther may still be like "oh no thats still to loud" in a few months i think, the NCT (thats ur MoT) is setting it at a max of 90Db i think!! but untill then there is no set law...

do you have any idea about the implications of a more restricive backboz on my engine mate??

ta

[stevieturbo]

Actually the law is an arse, but whats new there.

There is no legal limit, the cops ahve no test equipment. they have never been trained to use any such equipment nor has any been through approval, and there arent any guidelines as to how any such test would be carried out.

Sadly their ears can be deemed expert equipment, and they can claim excessive noise, without any evidence whatsoever.

We're fighting a losing battle as car owners. And short of a violent campaign, we've no chance of getting anywhere either.

As for the exhaust. If you post in english its easier to understand.

So is the exhaust on your car standard or not ? Standard they didnt have 3 or 4" back boxes, so what is on the car ??

And there are systems available that perform very well, and are also quite quiet. Your car is I assume standard, so not making a huge amount of power. So it would be quite easy to get a good flowing exhaust that is also quiet. But if it already has a standard system like you claim, then chances of getting one any quieter, is rather slim.

[GavinPearson]

I would have thought if you look at Construction and Use regs you could see the allowable spec and demonstrate compliance.

Of course if you were out of spec you could say that SVA had deemed it acceptable.

All this will cost money so maybe a Supertrapp or similar may be the answer.

[stevieturbo]

construction and use is ...well, not good

Basically, any deviation from the manufactureres standard is deemed illegal. Or anything to make it noisier.

But usually, cops were busyn tackling crime to worry about such silly things.


It seems the cops have removed all otehr crime from our streets now, so they are stooping to mega low levels of non-crime, and targetting motorists for fine generation instead with silly laws.

[goosie208]

yeah the backbox is 3.5 inch, from talking to the guy who owned it before me in Japan via email, he said it is a genuine scooby part, he got it from Subaru when it blew the last time and before that it was the exact same.. its just a sticky situation with this police bs as they wont have none of it!! the car isnt totally standard a differant turbo was fitted before it was shipped but the power hasnt changed much id say!

iv decided to (as NWA once said) FLOCK THE POLICE! ill prob never see that doucher again.. just dont wana get the car taken off me lol!

[stevieturbo]

IMO, all car thieves should be treated with the contempt they deserve. That includes cops who want to steal peoples cars.

One piece of advice, given their current agenda to criminalise motorists and threaten theft of their car.

Carry spare keys with you.

Naturally one of the first things they'll ask yo to do if they intend to steal your car, is ask for the keys so you cant drive off. TBH, there isnt a hope in hell I'd be letting any cop steal my car. I'd drive over them first.

So carry spare keys...or a dummy set. If they ask for the keys, hand them over, but then you need to get a coat etc out of the car. Which should be fine as they have the keys.

Then drive the car to a safe location, safe from theft.

[tangent police]

GavinPearson said:

I would have thought if you look at Construction and Use regs you could see the allowable spec and demonstrate compliance.

Of course if you were out of spec you could say that SVA had deemed it acceptable.

All this will cost money so maybe a Supertrapp or similar may be the answer.

Supertrapps do not flow if you have few enough plates for them to provide any degree of silencing.

David Vizard did a load of tests.

Turbo boxes are pretty easy things to source. Just get a box with huge flow, you don't have to worry about gas speed or shockwaves. Just flow.