To Cat Or Not To Cat

[DS-ZILR]

Gday crew just wondering what people are running on their cars cat converter-wise i want a bit more flow/grumble in my exhaust think its still running a stock cat converter. how have people done about either a high flow cat or a de-cat pipe? anythin that will stuff up the O2 sensors? any recomendation?

any helps good help.

thanks crew

Dion

[R33GOD]

any restriction whether it be a hiflow cat or stock will be just that.

obviously having a decat pipe/ hollow cat will be much better in power and response.

but is it really worth the fine??

[R31Nismoid]

O2's are before the cat, so no effect.

[MBS206]

I run high flow. I might be able to gain 3RWKW at max with it removed. System flows well enough

[Nacho Vidal]

I had a bad experience once with a supposed "high-flow" cat, and lost a fair bit of top end, however id love to see some back to back results of these modern style metal cats that i see a lot of users running. Currently running a Just Jap decat pipe. would recommend it if you want to go the decat option as its nice quality. Make sure youve got a good front pipe too.

[TiTAN]

if you choose to not run a cat and get defected/epa tested, prepare to bend over and touch your toes.

[R32 Driver]

swap over the stock cat before the inspection?

stock cat is 2" or something small

just get a 3" running all the way

[Shaun]

Im using a metalcat brand cat converter and ive noticed no power losses at all. Ive got two front pipes; one with the cat and one without, but i cant tell the difference except for the stain i get on the rear bar without the cat. Im using 3.5 inch exhaust, 4in cat and flows 350kw without a drama.

[Johnny]

Ive got a decat pipe from justjap. One of the best and cheapest mods ive ever done for power and response.

just make sure you keep a stock cat in case you need a rwc or epa instection.

[DS-ZILR]

thanks peeps helps a fair bit! will prob go the high flow a good name one to be on the safe side of both the law and performance.

yeah i wasn't too sure about the O2 sensors as i work for fords product development and we have pre and post cat sensors to check cat operation in the falcons and fpv's. shame

thanks again

Dion

[Adriano]

LOL at good quality decat pipe, its a piece of pipe with 2 flanges, what difference can there be in quality? Keeping the cat at home is no good when you get pulled over and fined for not having one"Officer, i just left it at home"

[joeyjoejoejuniorshabadoo]

A good decat pipe will be impossible for a cop to pick... They may smell it, but can't prove it. They can epa you, but you then have 28 days to fix it up

[Adriano]

But if you get pulled over by the rta, they can pick it, and all of the off the shelf "high quality"decat pipes are able to be picked by the cops. The only way to get around being picked by the cops is to have a pipe welded through the guts of a stock cat.

[tridentt150v]

Not worth it, high flow $300.

Fine max $10,000 or something, on a rwkw cost benefit analysis, you would likely be paying something stupid like $2000 per kilowatt.

There are other mods out there that will give many more kw per $$$$

[bozodos]

yeah think i'll get rid of my cat for off road use to see how much if any the difference is!

[SLY33]

LOL at good quality decat pipe, its a piece of pipe with 2 flanges, what difference can there be in quality?

In answer to your question, obviously functional quality of a decat pipe wont vary much, but there are definite differences in quality of materials and fit and finish among many of these so called "bolt-in" pipes.

[DS-ZILR]

yeah if i was to do a de-cat then i would deffinitely get the shell of one welded over the pipe where i am in vic dont have any rta crew bootin round pickin up crew just cops, and i never been pulled over yet always waved through busses and stuff so i think i will be right.

[Spoolup]

If you want to pay the $ - there are cats available that will flow as much as you want to go.

I have a CES cat and make 581 rwhp - we dropped the cat on the dyno and picked up 7 extra whp.

I have used one of the cheaper cats on the market who claim to be the beex kneez - it melted the internals after 7 power runs.

[bnr#@]

Why are people only concerned about outright power? Sure it may have only picked up 7hp at the top but what about midrange? What about on/off/on again throttle response, fuel economy?

Doing a dyno test tels you sweet fa realy about the drivability differences between having and not having a cat.

[benm]

lol the extremes/risks some people go to for an extra 5kw baffles me...