Main cat removal....
Main cat removal....
Author
Discussion

Mad Mitch

Original Poster:

842 posts

258 months

Tuesday 28th March 2006
quotequote all
I have sleeved the centre silencer... If i now take the y piece, cut and remove main cat and re weld what effects on sound can i expect.( i will be buying another cat for mot time )
Pre cats are still in.
Mitch.

andy-w

1,987 posts

256 months

Tuesday 28th March 2006
quotequote all
cant help you with what it might sound like but am very interested to know the results!!!
I have sleeved my center box (ouch) and have both the precats and main cat in.

zippee

14,128 posts

264 months

Tuesday 28th March 2006
quotequote all
AFAIK if you just remove the cat from the existing Y piece the effect, whilst very loud, is also a bit tinny and too bassy.
Your best bet would be to buy something like a new ACT de-catted Y piece (approx £220). This would not only look better as its stainless steel but also sound better as it has a narrower neck. Plus it'd mean you could keep your existing Y-piece for MOT time.

Mad Mitch

Original Poster:

842 posts

258 months

Tuesday 28th March 2006
quotequote all
Cheers zippy and andy..... Andy, just reading other post about popping etc... Looks like we are both after a little more noise for the summer....
Zippy... What difference would be heard by removing the pre cats as well as main one. Would it be worth the extra effort in your oppinion or will the main cat make a big difference???

andy-w

1,987 posts

256 months

Tuesday 28th March 2006
quotequote all
A local lad up here has a chim with no cats and sleeved rear silencer and it is loud!!!
As in it is quite painfull when you are behind him and he puts his foot down!!!

Plenty of going on at the weekend. Never liked cats anyway!

zippee

14,128 posts

264 months

Tuesday 28th March 2006
quotequote all
Mad Mitch said:

Zippy... What difference would be heard by removing the pre cats as well as main one. Would it be worth the extra effort in your oppinion or will the main cat make a big difference???


In my experience it didn't do a lot at all! Some people say theres a huge increase in noise but all I found was it gave a very small increase in depth of noise, ie/ a deeper rumble - but not by much.
The rear box conversion is what really made the difference, something I had done about 2 mths after the new manifolds.
I've also looked into the main cat removal - seriously considering going down the ACT route but can't quite convince myself to do it just yet!

225

1,331 posts

256 months

Tuesday 28th March 2006
quotequote all
Well IMO just getting the straight through silencers is about right, Austec had a griff there which must have had no cats at all and was too loud! Never thought I'd say that but wouldn't want to be pulled by plod all the time just because they heard me coming 2 miles away! You can keep things at a reasonable level if you dont floor it when the BiBs are around with the straight through whilst turning heads dwon the other end of the high street if you stay in gear for long enough should the coast be clear.

ntel

5,051 posts

270 months

Tuesday 28th March 2006
quotequote all
When I had a Chim, I removed the precats (well they mostly removed themselves) and replaced the main cat with a 200 cell free flow sports cat from Blackthorn Catylist. Even though I didn't sleeve the main silencer the sound was glorious as the new owner would tell you. I'm sure if I had sleeved the main box then the sound would have been ear spliting. I had no problems with the MOT's at all. In fact the emmissions were very low indeed.

mack

268 posts

287 months

Tuesday 28th March 2006
quotequote all
zippee said:
AFAIK if you just remove the cat from the existing Y piece the effect, whilst very loud, is also a bit tinny and too bassy.


Steve,
I agree with zippee. When I removed my main cat it just sounded 'hollow' with a very pronounced 'tappet' noise - not very nice at all!

I'd also suggest going down the JP/ACT route, if you want to improve the sound after decatting, rather than just removing the main cat - otherwise you'll just be disappointed with the result!

FWIW mine's fully decatted, with a sleeved back box, and I don't think it's too loud at all - even on long runs

cossiemetro

1,092 posts

270 months

Tuesday 28th March 2006
quotequote all
anybody got any sound files of a reving chim ????

Mad Mitch

Original Poster:

842 posts

258 months

Tuesday 28th March 2006
quotequote all
Thanks for all the replies guys.... Guess i will have to give my next move some thought

900ss

104 posts

254 months

Tuesday 28th March 2006
quotequote all
No Cats !!
3" system, straight through all the way, single 3" back box
4.0ltr chim mota no longer in a chim any more, but you'll get the idea

http://homepage.ntlworld.com/wyn1269/

Mad Mitch

Original Poster:

842 posts

258 months

Wednesday 29th March 2006
quotequote all
900ss.... that certainly has the nascar sound no mistake...That has made my mind upfor me
The neighbours are pd off with me anyway so a teeny bit more noise wont matter

900ss

104 posts

254 months

Wednesday 29th March 2006
quotequote all
This might give you a better idea of what it might sound like on the move.
Same car but a drive by this time!
You can make it sound as loud as you like still, just adjust your right foot lol

http://homepage.ntlworld.com/wyn1269/