decat pipe query

Post Sat Dec 13, 2014 5:45 pm

I've recently got my e30 316i on the road and I would appreciate more grunt. Ive been reading up on them and they look like what I want. I know a decat isn't going to change the power massively, it's for the sound.
Does anyone know where I can get one or is it easier to fabricate one?

Post Sat Dec 13, 2014 5:48 pm

Standard 316i m40 down pipe?

Post Sat Dec 13, 2014 6:04 pm

sweep wrote:Standard 316i m40 down pipe?

they're all silenced or fitted with a cat that I know of

Post Sat Dec 13, 2014 6:20 pm

What country are you from? In the UK only the Aug '92 onwards cars had cats as standard and I think it would be mainly tourings. Any pre-92 M40 front section won't have a cat, but will have a silencer.

If it's for sound, I think you'll be disappointed... I removed the cat from my M40 and it made no difference to anything.

Post Sat Dec 13, 2014 6:24 pm

jmc330i wrote:What country are you from? In the UK only the Aug '92 onwards cars had cats as standard and I think it would be mainly tourings. Any pre-92 M40 front section won't have a cat, but will have a silencer.

If it's for sound, I think you'll be disappointed... I removed the cat from my M40 and it made no difference to anything.

it's a 94 touring

Post Sat Dec 13, 2014 6:34 pm

If you're from the UK it will fail an MOT with no cat.

Post Sat Dec 13, 2014 6:36 pm

Removing the cat on a '94 car = MOT dramas

The power gain by replacing a good functioning cat with a non cat front section will be negligible .

Post Sat Dec 13, 2014 6:44 pm

maxfield wrote:If you're from the UK it will fail an MOT with no cat.

that's why I want a fabricated pipe so I can swap it over

Post Sat Dec 13, 2014 6:55 pm

lellis wrote:
maxfield wrote:If you're from the UK it will fail an MOT with no cat.
that's why I want a fabricated pipe so I can swap it over

Just keep the cat and save yourself time, money and trouble. Removing the cat really made no difference at all on my touring.

Post Wed Dec 17, 2014 9:24 pm

If your planning on doing this all just for noise why don't you just stick an induction kit on it..

Every time you floor it you'll hear it grunt

Post Wed Dec 17, 2014 10:00 pm

i think you'll get a few more mpg from a decat but i'm not sure .....

Post Wed Dec 17, 2014 11:23 pm

Removing the cat. from a M40 does little for power output, but as Tommek says, will give a noticeable gain in fuel economy.
There are loopholes that can be exploited to get around the MOT test problem. The test emissions limits apply to whichever is oldest out of the engine and body, so a pre 09/91 engine will solve the problem, as will one whose age cannot be identified because the engine numbers are unreadable. Older limits also apply to any post 08/91 car fitted with a post 08/91 engine, such as any E30 with a M5x engine, or any RH drive four door or touring with a M42 engine.