View Full Version : CAT or NO CAT
MINIHORSE
25th December 2006, 12:29 AM
Just a quickie, who on here has their cat taken out,
apart from the obvious horn sound your car will produce are there any other
advantages of having it removed? are there any power/torque increases?
would it be wise to run a straight pipe or would you need a resi or a muffler
to stop some of the noise?
also being a pre 84 vehicle can mine be legaly run without a cat??
Course_Out
25th December 2006, 12:36 AM
If your car came from the factory with a cat you legally have to run one. An old blocked up cat will cost power obviously but if you put in a new high flow cat I'd doubt you would notice the difference between that and having no cat at all on an N/A engine.
Apparantly the fine for not running a cat is quite painful as well if the rumours are true
Gilly
25th December 2006, 12:40 AM
i at present run no cat.
NOT GOOD
massive fine as far as i'm aware if i'm sprung by the EPA not running one.
there would be a negligable increase in not running one (as in wouldn't feel a difference on a 4age IMO)
cat convertors aren't designed to quieten the exhaust at all, they do slightly but again the difference isn't noticable.
i say run a cat, hi flow one, R33gtst cats flow really well and is what i'll be using when i can be arsed to get flanges welded on to my exhaust.
yoshimitsu9
25th December 2006, 12:47 AM
somthing i might throw in
FYI it is the engine age that is pre date emission laws does not "legally" need to run a cat so just because ure car is an <83 model doesnt mean u dont have to run a cat if uve done a 20v 4age conversion for example.
but why make complications with the boys in blue? just run one any way so u dont have anything to worry about
MINIHORSE
25th December 2006, 12:53 AM
this is what i have on the car at the moment, also with a cat but as the car was imported im not sure the cat is standard, i love the sound of this tip and it has silencer sleeves i can remove
also the cat has a flange on either side of it so i presume a straight pipe can be bolted in there for track days etc
Its a trust DD exhaust, looks minta on the car but i need to spend a couple of hrs on it with the autosol
Gilly
25th December 2006, 01:11 AM
yeah you can unbolt the cat and replace with straight pipe for track days, t3 make such a pipe, from memory they call it a "test pipe" or something like that.
and yes cat requirement is to do with engine age not vehicle age. if that engine in its original car used a cat or any other emission control devices, they need to be fitted and operating in the new recipient car regardles of age.
no cat fine is something crazy like $10,000
DRFT - 86
25th December 2006, 04:48 AM
I had my whole exhaust done the day before getting blueslip in NSW...
I had it all worked out on paper and left it at the shop to get done... I had a cat written down to be added, as my old system had one... The lad at the shop phoned me and said I didnt need one as it was a pre 83 car.. (JDM bigport) I was like man are you sure? as Im going for a blueslip tomorow.. so I called old mate who was doing the inspection to see if Id pass without a cat, ended up saying yep no problems... so didnt bother with the cat...
also they do sweet f.a to the noise factor... Ive run mine straight off the headers, with and without the cat... and the difference is minimal ....
Jason
25th December 2006, 09:02 AM
And i would get a cat to avoid possable problems, becuse when you talk to the transport dep. you always get mixed answers
Touge205 thats looks like a sweet system ive always had a soft spot for dual pipes, looks expensive but what kind of noise dose it make ? im looking for somthing quiet
Brenton 86
25th December 2006, 09:13 AM
If you need to legally run a cat its easy to hollow them out, just get a large drill peice or small whole saw and turn it into a straight pipe. Apparenty you can tell if its hollow by tapping it on by i certainly couldnt cos the casing on the nasty standardish ones are pretty beefy. Also the insides of cats can blow out after time so you'd have a pretty good argument for it being hollow on a 25yo car. I run no cats or muffler but my pig is a defect special and was pulled off the road so ill be installing a hollow cat very soon.
lo_rolla
25th December 2006, 09:46 AM
My car doesn't have a cat, and as far as I'm aware it does not need one.
It's a 1983 Trueno Sedan with the standard motor, can some one clear this up for me?
MINIHORSE
25th December 2006, 10:51 AM
And i would get a cat to avoid possable problems, becuse when you talk to the transport dep. you always get mixed answers
Touge205 thats looks like a sweet system ive always had a soft spot for dual pipes, looks expensive but what kind of noise dose it make ? im looking for somthing quiet[/b]
Yeh it sounds quite good, im guessing cos it is a TRUST system and it is tuned to the car, on idle it sounds rather quiet, but when you floor it at about 4k rpm it starts to scream, im guessing its more to do with the cams it has, but without the silencers its very very loud
but its an awesome note tho
heres what it looks like on the car
ae71neo
25th December 2006, 03:11 PM
I dont run one, $10,000 :S Maybe i will get one put on haha!
Gilly
25th December 2006, 04:42 PM
I dont run one, $10,000 :S Maybe i will get one put on haha![/b]
http://www.ae86drivingclub.com.au/forums/emoticons/laugh.gif i don't think anyone has actually been done for it, just a scare tactic perhaps. i remember the transport officer telling me when he defected my Gemini for being too loud, they were doing roadside vehicle inspections up here in QLD 2 yrs ago. just on any main road too it was weird you come over a hill and they would just be there on the side the road with sniffer pipes and decibel meters and shit.
don't do it anymore though.....
jezz
25th December 2006, 04:58 PM
A mates car got epa'd running a 4agze with no cat, car reged as 1983 which passed an epa inspection, so who knows.
I had my whole exhaust done the day before getting blueslip in NSW...
I had it all worked out on paper and left it at the shop to get done... I had a cat written down to be added, as my old system had one... The lad at the shop phoned me and said I didnt need one as it was a pre 83 car.. (JDM bigport) I was like man are you sure? as Im going for a blueslip tomorow.. so I called old mate who was doing the inspection to see if Id pass without a cat, ended up saying yep no problems... so didnt bother with the cat...
also they do sweet f.a to the noise factor... Ive run mine straight off the headers, with and without the cat... and the difference is minimal ....[/b]
parrot
25th December 2006, 05:08 PM
http://www.ae86drivingclub.com.au/forum/in...lytic+convertor (http://www.ae86drivingclub.com.au/forum/index.php?showtopic=7623&hl=catalytic+convertor)
us_ae86
25th December 2006, 05:34 PM
i like cats. i'm not much of a dog person.
Cerby
26th December 2006, 01:55 PM
when i got my exhaust done i got everything replaced from the extractors back! I asked the guy who was doing it if i needed a cat and he told me no. i asked him if he was sure cos it needed to be legal! And he said that the 4age red top that i had has done over 100000 kilometers so i don't need a cat?!
I didn't beleive him so i rang a couple of other places and asked them and i got the same answer everywhere i went!!
I'm pretty sure this is cos i'm in tas but i've heard that they are going to start bringing our laws up to standard with the mainland so i'm not sure what the go will be then!
Cheers
Cerby
Basic
26th December 2006, 05:03 PM
My car has a decat pipe with a cat shell welded together over the pipe, if you get under and look real close you can tell but at a glance you'd never know the difference. Obviously this wouldn't pass an EPA but I think the laws are a little different in WA anyway.
Orange hachi
26th December 2006, 05:35 PM
My car has a decat pipe with a cat shell welded together over the pipe, if you get under and look real close you can tell but at a glance you'd never know the difference. Obviously this wouldn't pass an EPA but I think the laws are a little different in WA anyway.[/b]
your one sounds like a good idea
i might have to try to find some cat shell
and do the same thing
lol
sorry to be a copy cat
http://www.ae86drivingclub.com.au/forums/emoticons/smile.gif
Basic
26th December 2006, 11:41 PM
<{POST_SNAPBACK}> (index.php?act=findpost&pid=296356)
My car has a decat pipe with a cat shell welded together over the pipe, if you get under and look real close you can tell but at a glance you'd never know the difference. Obviously this wouldn't pass an EPA but I think the laws are a little different in WA anyway.[/b]
your one sounds like a good idea
i might have to try to find some cat shell
and do the same thing
lol
sorry to be a copy cat
http://www.ae86drivingclub.com.au/forums/emoticons/smile.gif
[/b]
The guy who had the car before me did it. I didn't even know about it until I was fixing up an oil leak and noticed it. The cat is shell is pretty much just tacked onto itself and 2 spots on either side of the pipe but you can clearly see the pipe inside it. You could probably do a much better job taking a bit of time with it.
rthy
27th December 2006, 12:47 AM
save a tree
install a cat
Powered by vBulletin® Version 4.2.3 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.