Deleted by Request

..i am having made a side exit exhaust to come out the drivers side not far from front wheel with NO silencers...can anyone tell me if its illegal?..and does anyone know if it effects engines ie..better flow etc..its 3inch all the way thru.

PS is this a new start for everyone on here?Looks great and big up the hacker for getting this to happen.

Dangerous Malcolm..

Good to have you back Phil.

Deleted by Request

Yes i know..but can you answer my question.

BigChuck

my car failed an mot for a loud exhaust,
"Exhaust system noise is clearly in excess of that emitted by a similar vehicle fitted with a standard silencer in average condition [7.1.2b]"
a friendly mot tester might let it go, but mine was really really loud.

Deleted by Request

BigChuck my car is on a Q plate though..so no emmissions check so i thought maybe no noise check as its a rally car?

BigChuck

the emissions on mine weren't tested because it didn't have a cat on it, i don't know how the rules go for q plates or rally cars, there may be special exclusions for them.

Deleted by Request

..bigchuck surely if no cats were fitted it had to still be below the 3.5%?

Rick

It won't be legal due to the noise levels. Minimal effect on the engine if you were using straight through silencers. You really need to get a silencer on it.

C4llyT

Sure there are ways and means, and a turbo does a lot of silencing.
Exhaust wrap and something stuffed up the end for mot to quieten it, often a way round these things.

BigChuck

mine was on an N reg car so a cat was required

C4llyT

Mine's N reg and has no cat test

CossieRich

iTrader: (1)

Do you know a freindly MOT tester Phil?

Dangerous Malcolm..

You might have to put it through a SVA instead. Noise still has to be within a certain level.

Quote:
Noise This checks that vehicle is fitted with a working and secure exhaust system. The noise level is checked and must not exceed 101dbA

trevCOSS

iTrader: (6)

the rally saffs ran a similar system to this anway so I cant see it being to much of a problem, not many mot testers will test the car on boost at 7k lol and with the turbo helping to silence I cant see it being that bad

C4llyT

When I did mot's, and all others I knew, never ever heard of a loud exhaust being failed.
Way it's worded is a funny one, similar vehicle with silencer in good condition - nothing to say it has to be standard silencer, so a dustbin on similar vehicle will be as loud as on your car, for example.
Completeness of system may be the sticking point.
Case of beer each year saves me buying 2 new cats.

dojj

iTrader: (3)

i had one box on mine and it was fine

and i know of someone else who's got none and he's fine too

BigChuck

the problem with mine was it was way over the top, 2,3/4 inch from the manifold straight through to the bach where it had a twin 5 inch back box, on a 2 ltr nissan primera, i can honestly say its the loudest exhaust i have heard on a car.

C4llyT

I suppose you could bodge a silencer in for mot, same as people replace the cat for it.
Dunno, best to leave a £20 note on passenger seat really

sexr3i

I asked my local MOT man about this once when asking about side pipes. If it hasn't got any boxes, it's not doing it's job so isn't road legal.

dannyblackpool

you will get a certain blow by past rear oil seal of turbo due to reduced back pressure, nothing drastic on a healthy unit but noticable,but obviously better flow...

SS1

iTrader: (3)

phil why the drivers side rally yes ..road use NO

it still wont pass unless its a screamer pipe and you can control the flow

Rick

Why would you not want to run a silencer, it's a bizzare idea.

Dan

If it has no boxes then what about the back pressure?

C4llyT

It's turbo'd.

NUTS RuS

iTrader: (35)

Exhaust wont be illegal, you can do what you want, but if its too loud it will fail construction/use regs.

Stavros

In performance terms you dont want ANY backpressure in your exhaust after the turbo at all, and on any performance 3"+ exhaust you WONT have any backpressure at idle at all, so IMO thats poo.

ECU Monitor Enthusiast

iTrader: (1)

Stavros,

From my understanding of turbo design...

At idle, the turbo isnt spinning much and the force on the bearing seal is minimal
as also the oil pressure is lower so the seal can hold back the oil.

Dan

I see