Where's the cat at.

[Monks]

Hey y'all,
New here and first post.
I have installed perrin cat back and mx performance front pipe with cat and over pipe.
I want to get headers and looking at hks catted EL headers. Looking for advice on whether I should keep the cat on front pipe or get a straight through to replace front pipe or is it better to get a catles header?
I am after best performance and not interested in sound per say.
Cheers
Monks.

[steve99]

Originally Posted by Monks

Hey y'all,
New here and first post.
I have installed perrin cat back and mx performance front pipe with cat and over pipe.
I want to get headers and looking at hks catted EL headers. Looking for advice on whether I should keep the cat on front pipe or get a straight through to replace front pipe or is it better to get a catles header?
I am after best performance and not interested in sound per say.
Cheers
Monks.

If you dont care about being legal or noise remove both cats , but you will need a tune to take best advantage from you mods

[Monks]

Have to stay legal. Do you need both to stay legal? Catback is resonated. Also have oft for tuning.

[Captain Snooze]

Originally Posted by Monks

Do you need both to stay legal?

It is illegal to remove any emissions control equipment.
If (and I understand it's a big if ) you get caught running catless you can face a fine of around 12k and possible impoundment.

Originally Posted by blue cat

So does this mean there's no legal way to change the headers on this car in Aus at all?

Originally Posted by Captain Snooze

It is legal providing you do the following
-You no not remove any emission equipment so this means you have to use a catted header.
-You have the dB level checked by Engineer.
-You have the car tested for emissions at relevevant RTA. In Sydney there are only 2 places to do this. From dodgy memory these are Botany and Penrith. This is a dynamic test on a dyno.
-You have the emissions signed off by Engineer
-You take paper work to RTA and have them sign off.

To stay 100% legal the tune should be tested and signed off as well. Understandably not many people bother with this.

It's "per se", not "per say".

[Monks]

Thanks Captain,
English was never my strong point.
So you need both cats to stay legal??
Just call me forest.

[Captain Snooze]

Originally Posted by Monks

So you need both cats to stay legal??

Correct.

[Malt]

I understand that Australian laws may be different than here in the States but if you wanted to get technical about it, simply having two cats is not enough. By the letter of the law you are not allowed to replace a functional/undamaged cat. This means that even if you have a high flow cat in place of the stock cat, you are still in violation of the law. I think this is one of the reasons Perrin quit making aftermarket emission equipment.

Is a police officer going to know the difference between the factory emission equipment and a quality aftermarket piece? I doubt it, but if you are that worried about getting caught then its probably best to remain stock for emission related components.

[Captain Snooze]

Originally Posted by Malt

I understand that Australian laws may be different than here in the States but if you wanted to get technical about it, simply having two cats is not enough. By the letter of the law you

Whose laws are we talking about? That is not correct here. If a part meets or exceeds the Australian Design Rules for that part then that part is deemed to be legal. Providing the exhaust is under the dB limit and passes the I/M240 test then it's ok.
In Aus if a car has been certified as being modified there is a sticker placed on the car listing the mods.

(I will need an A4 sized sticker soon lol)

[Malt]

Originally Posted by Captain Snooze

Whose laws are we talking about? That is not correct here. If a part meets or exceeds the Australian Design Rules for that part then that part is deemed to be legal. Providing the exhaust is under the dB limit and passes the I/M240 test then it's ok.
In Aus if a car has been certified as being modified there is a sticker placed on the car listing the mods.

(I will need an A4 sized sticker soon lol)

I thought I was pretty clear in my post who's laws I was talking about. I even went so far as to say that it is probably different in Australia. While my post may not have been beneficial to the OP, surely the hundreds of others who read this forum may get valuable information out of it as there is this idea that replacing a cat with a high flow cat maintains legal status in the US, which is simply not true.

You see vendors promoting their products as legal simply because it maintains a cat, which not only is misleading but can have the effect of causing consumers to purchase something that is inferior in terms of power potential but also just as risky when it comes to emissions/inspections. Sure there are other reasons for buying catted exhaust products (you don't want to smell an uncatted exhaust, you like hugging trees, you might fool an inspector for your annual inspections, etc...) but I hate seeing misleading information (at least here in the US) being spread. Please keep in mind this post isn't directed at you specifically, just a general statement.

[Captain Snooze]

Originally Posted by Malt

I thought I was pretty clear in my post who's laws I was talking about. I even went so far as to say that it is probably different in Australia. While my post may not have been beneficial to the OP, surely the hundreds of others who read this forum may get valuable information out....

My apologies. I was thinking too narrow mindedly.

[Monks]

Thanks guys for the advice,
Have decided to go for both catted. Later on I can get an uncatted front pipe.
Going for 4-2-1 which I've been told will remove most of the torque dip.
Thanks again

[s2d4]

lol, good research.