Exhausts

Post Wed Dec 07, 2005 5:28 pm

Going by whats happening on the group buy side of things and scorpion boxes, Was wondering if it would be legal to run just a back box, and straight pipes from manifold to box. No middle box. I used to have a jeep back in oz and put a hotdog exhaust (Glasspack/Cherry bomb muffler) instead of the back box.. sounded like a V8 when you idled.. and revved.. sounded the ducks nuts!! Scared a few 1ricers in a tunnel once! Trailing throttle used to barp and bubble.. sounded really mean!!

Post Wed Dec 07, 2005 5:35 pm

totally illegal.
there is a lot of police officers that are being trained on whats legal and not on cars these days.if a car was built with a cat then its illegal not to have one on there and can even fail a m.o.t, only cars made before 1973 are very unlikely to have a cat such as a classics.

hope you dont get caught if you do it.

Post Wed Dec 07, 2005 5:44 pm

im sure u mean 1991/2 mate that is when it was made a legal requirement for a car to have a cat fitted

Post Wed Dec 07, 2005 5:48 pm

TOURINGDADDY wrote:im sure u mean 1991/2 mate that is when it was made a legal requirement for a car to have a cat fitted

I hope so because my sport had factory CAT delete according to spec printout from the original dealer

Post Wed Dec 07, 2005 6:43 pm

Yeah, its 92.

Post Wed Dec 07, 2005 6:47 pm

92 k-reg onwards has to have a CAT anything older and u are ok.

not sure if u need a centre box for MOT,but theres folks on here who just run a back box and some of them are not silly loud either

Centre boxes on E30's so i'm told don't have alot of baffling in them anyway

Post Wed Dec 07, 2005 6:56 pm

I used to only run a rear box.Not loud,just sounded better.
Passed MoT ok also.

Post Wed Dec 07, 2005 7:02 pm

ther we go then! H reg or older and u can run no centre box

buster the car must of been fine on emissions then too? not that they are too strict on cars of our age

Post Wed Dec 07, 2005 7:45 pm

Don't run an I6 without the centre box or at least a cross-over pipe in place of the centre box. You'll lose low end torque!

Cars built before '92 (and whatever the cut off date for CATs is) can legally run without one, even if they left the factory with one.

That's why pre '92 RX7s are so popular

Post Thu Dec 08, 2005 10:56 am

mines G reg.. so I should be ok.. but whats the crossover pipe? I know what it is on a V8.. but never heard of this on a I6

Post Thu Dec 08, 2005 11:09 am

the exhaust, from an MOT point of view, is considered a Noise reduction device, It has to reduce the noise of the exhuast down to something like 80db (i Think, chance's are i am wrong).

Post Thu Dec 08, 2005 1:34 pm

Last I heard, for bikes there was a specific limit, for cars it's down to the discression of the tester.

The centre box on the 6cyl exhaust system serves as a crossover. Remove this and the crossover goes with it

Post Thu Dec 08, 2005 1:36 pm

Im currently looking to get an exhaust made with cross over pipe but no centre section. Defo sounds better!

Post Thu Dec 08, 2005 1:48 pm

Supersprint 2-peice rear sections have a crossover built in...

Post Thu Dec 08, 2005 2:18 pm

im guessing the crossover is basically where the 2 pipes go into 1 chamber, then out in 2 pipes??

Post Thu Dec 08, 2005 5:02 pm

sure is

Post Thu Dec 08, 2005 5:06 pm

Really well built back boxes - quite expensive but real piece of kit.

Post Thu Dec 08, 2005 6:17 pm

kam-325i wrote:the exhaust, from an MOT point of view, is considered a Noise reduction device, It has to reduce the noise of the exhuast down to something like 80db (i Think, chance's are i am wrong).

your close

it was 78 decibels i was told by two MOT testers when they failed me on my golf exhaust