How much extra "noise" will a de-cat make?

[brakedust300]

Im thinking of de-cating sometime soon and wondering how much extra noise i will get?

[Dave 500]

Lots

[Nefarious]

Enough to make it actually hurt a bit sometimes

edited to add: Just FYI, but there are no noise limits at Knockhill

Edited by Nefarious on Wednesday 9th January 10:53

[cerbfan]

Another Cerb in Dundee, the North East of Scotland is full of them now. Just wish an Indy would set up, up here now.

I have decats and it is very loud, so much so the neighbours complained that it actually rattled there windows and they could hear me a good 5 minutes before I got home.

I've now got teh new ACT system which has cherry bomb silencers in place of the decats. Its still loud but not quite as anti social and has a much deeper sound to it.

[RUSSELLM]

Std exhaust with de cat is my favourite combo.
It's quiet 'er' on tick over, but you notice the sound go up, over 3K revs.


I've got a sports exhaust & decat on the 4.5, and it's too much. Constantly droning along, and noisy on tick over....Doesn't win any favours with my neighbours.

[Mike Hawthorn]

I run a 4.2 without cats and with ATC pipes. It's a bit noisy at start up but no real problem at normal speeds. I've toured France etc. and don't find the noise a problem. Indeed my girlfriend seems able to sleep without any trouble at all!! My advise is not to worry but be sensible where and when you put you foot down. But frankly with these beasts that’s good advise whatever set up you have.

[Peasantplucker]

Dave 500 said:

Lots

I would disagree. Although the 4.2 is more raspy, my 4.5 is only marginally more noisey without cats, although it's certainly a much cleaner sound coupled with a few more pops and bangs, so definitely worth doing in my opinion, even if it is a pain at MOT time.

[hugepiece]

My 4.5 with linked de-cats doesn't seem any louder at all really until you really floor it, pops and bangs are more prevalent though :-)

[Ireland]

I have a sports exhaust and it's de-catted ..... and it's seriously loud.

I'm actually changing to a standard exhaust with a de-cat (after the next Irish tunnel run ) as it's way too loud inside the car at anything over 65mph.

Having said that, my 9 year old usually sleeps in the back when she's on a long trip with us even with the LOUD set-up.

[amazon]

Ireland said:

I have a sports exhaust and it's de-catted ..... and it's seriously loud.

Me too.

[m16kcy]

sounds like this!

<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/G822g8LIixs&rel=1"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/G822g8LIixs&rel=1" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>

[m16kcy]

sorry posted wrong link thingy it sounds like this!

http://www.youtube.com/watch?v=G822g8LIixs

[VYT]

Dave 500 said:

Lots

Lets put a number on it. 118dB without cats. 4.2 with standard rear box.