No cats

Adam · November 16, 2002, 08:47:57 PM

I'm more of a dog man and like my cars barking, so I wanna change my cat....i mean extra muffler. I see 3 ways:

1) the COOL way- chop the pipes, and join the pipes seperatly creating a twin pipe system. Thats a lot of work.

2) taking the box out and replacing it. Now id need to know when i can get such a length of pipe with the appropreate attachments. its a 2 inch system btw.

3) The poor mans way- edit the box.

Ok- are there places around who are willing to do some of this work- particularly example no.1 ??

Whats the official legal view? Coz cats wernt reuired in oz in 1980.

thanks

Adam

The White Knight · November 17, 2002, 03:18:23 PM

I had my cat rermoved sounds better & goes better
Regards W/K

Brutus · November 17, 2002, 06:55:24 PM

I would have thought that even tho cats weren't legally required by our dear legislators until 80, your car was required to have anything that was originally fitted still in place.

77CVT · November 18, 2002, 09:43:54 AM

Take the cat out yourself, drive to the muffler place (1/4 throttle!) and have them put a dual exhaust in. It cost me $120. I have since put in a full new exhaust but that is the best option IMHO.

Cats don't even work until they are hot anyway, so all these cars fitted with them driving to the bus/train station aren't even effectively using them.

rebel · November 18, 2002, 09:53:22 PM

I'm with 77cvt on this one .... you could argue that it should remain for originality sake as mentioned by Brutus above but that level of detail I feel is NCRS; since our cars are modified anyway by way of steering conversion, they don't qualify. It's an individual decision but if you decide to dump 'em, I'd take 77cvt's advice and replace 'em with a dual system.

Brutus · November 19, 2002, 04:13:56 PM

There is one thing that you should all be aware of and that is without the cats, the unleaded fuel is putting out more carcinogens than any leaded fuel ever did!

Btw, I'm not trying to preach, just inform. I don't run cats either.

Vette Obsessed · November 20, 2002, 10:48:53 AM

I don't really want to speak in the for or against on this topic. There are performance advantages to be had but also laws that will be broken if you pursue this route for greater noise/performance. What I do want to say is that in my opinion I think everybody here should be very careful what they say here as this is an open forum and ANYBODY can look in...

The fines for individuals and businesses that tamper with emissions controls and catalytic convertors are far from cheap. I'm not sure what the laws applying to the removal of cats on pre 1986 vehicles are but erring on the side of caution may be the best way to go as far as posting here is concerned.

(Takes "Administrator" cap off)It may be safer for some to edit their posts or keep things to e-mail in light of the legalities involved.(Puts "Administrator" cap back on)

I don't want to preach but I'm sure nobody wants a visit from the RTA or EPA.

:)

77CVT · November 20, 2002, 11:21:37 AM

All unleaded fuel is, is leaded fuel without lead! So I don't believe the argument that unleaded fuel puts out more "bad stuff" than leaded. ALL fuel is highly carcinogenic so try not to breath it in when filling up.

If it is not ok to run an unleaded car w/o cats, then why do they tell us it's ok to run some pre '86 cars with it? I has to be better than that LRP crap! That has so much magnesium in it it's not funny. :b4

Cats are only there to react with some gases and change them into another gas (there are 3 I think but can't remember which). as I said earlier, they don't even work until hot.

I don't think a muffler shop can legally remove a cat without replacing it with another.

Cheers

Adam · November 20, 2002, 01:24:36 PM

No need to worry, I'm sure were all talking about replaceing cats.

Adam

QuoteOriginally posted by Vette Obsessed
I don't really want to speak in the for or against on this topic. There are performance advantages to be had but also laws that will be broken if you pursue this route for greater noise/performance. What I do want to say is that in my opinion I think everybody here should be very careful what they say here as this is an open forum and ANYBODY can look in...

The fines for individuals and businesses that tamper with emissions controls and catalytic convertors are far from cheap. I'm not sure what the laws applying to the removal of cats on pre 1986 vehicles are but erring on the side of caution may be the best way to go as far as posting here is concerned.

(Takes "Administrator" cap off)It may be safer for some to edit their posts or keep things to e-mail in light of the legalities involved.(Puts "Administrator" cap back on)

I don't want to preach but I'm sure nobody wants a visit from the RTA or EPA.

:)

Vette Obsessed · November 20, 2002, 02:12:54 PM

Without getting into a lengthy discussion about pipe diameter relative to engine output/capacity and potential torque loss, I understand a TRUE twin pipe system will be louder and have a more authoritative tone than a system that merges dual pipes into one collector at any point.

It will cost more though (there is always a catch isn't there). :(

A crossover tube (AKA a h-pipe) located (in general) as far forward in the system as possible can be used to minimise reasonance and possibly gain a little more power with a twin system.

I would imagine that a twin 2" system would not be oversized for your motor - I'll check my little chart when I get home...

77CVT · November 20, 2002, 04:24:20 PM

Yes, a dual system will have a louder note & tone than a single. But generally speaking it will also have more power. I don't believe it costs THAT much more (unless it's stainless steel), after all it's only a 6' bit of pipe.

A H pipe should be positioned, from what I have heard, at the point where paint would stop peeling off it. This is directly behind the xmember in my vette, which is where the H pipe is (about the only place for an auto 'vette). The H pipe should also be of a lesser diameter than the primary pipes. Mine sure sounds melllllooowwwwwww now. :D :D

IMHO, a 2.5 inch dual system is a minimum for a decent 350. For power gains, see my thread in Pre 84 tech Tips. :D

Here is a link for Tech Articles. There is an article on balance pipes but I'll be darned if I can find it now! http://www.autospeed.com.au/show_free/S_technical/section.html

Set your 'vette FREE, and put in a decent exhaust system!

Cheers

Adam · November 20, 2002, 08:40:53 PM

QuoteFrom what I know a dual pipe system with a "x" style crossover is best. Than a H style crossover. It has somthing to do with having a constant flow rather than an eratic one due to the cylinders firing on opposing sides and into seperate pipes.

I guess that shows I'm getting old. I totally forgot about x-pipes. When I was learning about exhausts h-pipes were the done thing and x-pipes weren't really heard of also - doh!. You are right though. FWIW I have seen some x-pipes advertised that go from two 2.5" pipes into an "x" with a section of 3" - kinda defeats the purpose in my opinion - there are x-pipes around with a larger centre cross-section though which to my mind should? work better.

QuoteAlthough Im not really interested in that smigin more power that a crossover can provide.

Probably not worth the money when you consider the gain - especially if budget is a consideration.

QuoteHah, nevermind:)

Keeping things in perspective is probably a good idea. :) I've paid more than I needed to in the past just to get that "little bit better" when it wasn't really needed for my application.

Brutus · November 24, 2002, 07:49:42 AM

Quote
Set your 'vette FREE, and put in a decent exhaust system!

Cheers

Chris...I will as soon as I get the time to put my Hooker side exhaust and STS baffles on. Then we'll hear some music.:22

Adam · November 25, 2002, 11:27:04 PM

It's an interesting topic.
I know somone with a Ford Bronco that was bought in 1985 new. Still ran Leaded and obviously no cat.

The RTA says that for cars imported that are over 15 years old, the car must meet the ADR's of the date of manufacture to be legal.

Fianally, what if the car was imported with a modification, ie no cat. and got approved?

A

Brutus · November 26, 2002, 01:14:30 AM

For some reason commercial vehicles are/were exempt from some ADRs relating to cats, etc. but I have no idea why.
I had a 94 Rodeo that was never fitted with cats from the factory and it ran on ULP.

As for an imported vehicle that was previously modified when it was shipped here, I'd say the RTA would refer only to its OEM condition. Tho having said that I doubt that in most cases they would know what that condition would have been back then. For example....sidepipes on a Corvette.

rebel · November 26, 2002, 11:00:05 PM

QuoteFianally, what if the car was imported with a modification, ie no cat. and got approved?

<--- an Engineer's certificate would suffice but that'd be a hard one ot get according to the "ADR of the day rule".

Adam · November 27, 2002, 09:07:32 PM

Well the "ADR of the day" didnt call for cats on cars.

But heres a question: when were cats madatory? My Niki doesnt have one and they were imported from 89 to 92 or so.

Adam

77CVT · November 28, 2002, 09:37:55 AM

On Australian cars - 1986 from memory.

Vette Obsessed · November 28, 2002, 04:13:03 PM

QuoteOriginally posted by 77CVT
On Australian cars - 1986 from memory.

Sounds right to me. Thats when we got unleaded fuel.

Maybe the Niki was exempt because of it's weight, capacity, or type classification. Are they a four stroke motor are they (I know stupid question)? Commercial vehicles are subject to different ADR's but I'm surprised that some seem to have come standard without cats.

Adam · November 28, 2002, 10:40:09 PM

yea, maybe its just a measure of how much pollutants an engine puts out b4 a cat is needed.
The Niki is a 650kg 650cc monster with 4 glorious strokes. A true Italian 2 door, rear engined, rear wheel drive, red car, with a name that begins with F. Special research went into balancing this car, the engine actually sits BEHIND the rear wheels thus preventing wheelspin. I have the "big block" of the Nikis- as they also came in 600cc.

Anyway... What about LPG... is a cat useless if u have LPG? If not then im pretty sure an catless LPG car is cleaner than a petrol with cat car.

Wow, I'm impressed, all this cat talk and still no puss-y jokes.

Adam