High Flow Cat

[r`Geno]

A few questions for owners of high flow cats -

1. Did you find that it was a worthwhile mod?
2. Indications of power gain?
3. Any recommendations on a high flow cat to fit dc2r ?

Thanks in advance :thumbsup:

[typsy]

I have a Catco 2.5 inch high flow cat. I don't really know if there was a power gain, but i had to install it becasue my extractors had a 2.5 inch collector. I guess it would be an improvement over a stock 2.25 inch cat. It does give out this honeycomb type smell when 1st installed.

[rdruby]

the high flow cat made a small but noticable difference when installed with extractors

[euro1978]

Most high flow cats are a joke.

Its not how big the actual cat is, its the size of the holes in the block inside. Most high flow cats do not flow better than a stock cat.

[Felix]

Drill a nice big hole straight through the honeycomb stuff. Then you will notice some huge performance increases. or better still dont have a Cat convertor. Just dont get caught or you'll get huge fines.

[Benji]

you can get something that looks like a cat, but has nothing on the inside. i had one on my last car.

[Terry]

you can get something that looks like a cat, but has nothing on the inside. i had one on my last car.

Would that make the exhaust very loud?!

[Felix]

Would that make the exhaust very loud?!

Not nessessarily, but very illegal.

[nipnip]

JDM ITR cat isn't a bad option, though im not sure if it'll fit on our aussie headers. its good because it looks stock, some insurance companies won't insure you if your exhaust is more than just a cat-back apparently

[Benji]

i had a 2.5" exhaust on a 2L turbo and yes it was loud, but not because of the fake cat. yes it's illegal but how would you now unless you take it off and look inside... when i had the turbo replaced the mechanic also replaced the fake cat with a highflow cat (sounded the same) and that's how i found out after 2 years of driving the car.

i've heard ppl mentioning here in previous posts that you can fit a commodore cat and apparently they have good flow? i don't know if this is true though?

[MrPlow]

When many people install a Hi-Flow cat there are not really getting a hi flow cat- they are just getting a larger cat -

Ask for a mega (or super) hi-flow cat, has larger in's and out's, and much better flow! Noise is no differant to a "hi flow cat"


also the act which was mentioned about which has nothing inside is called a Hollow Cat... very illegal - but people risk it cause its very hard to tell without opening it up!

[nipnip]

had a friend with a suzuki swift gti, hollowed out cat. was standing out my house 4am in the morning waiting for him to pick me up. by the time i heard it, it took him 30 seconds to reach my house, thats how damn loud it is. and where i live, its DEAD QUIET 4am

[euro1978]

Easy for them to tell

1. Lack of a strong distinctive heat source under the car where your cat (normally the hottest part of the exhaust) is meant to be (they have a device that can detect this I believe)

2. When a car is 'catless' the smell of the exhaust is quite distinctive because it is a much more pungent smell due to the cat not being there to do it's job.

$10,000 fine last time I checked

[Felix]

Easy for them to tell

1. Lack of a strong distinctive heat source under the car where your cat (normally the hottest part of the exhaust) is meant to be (they have a device that can detect this I believe)

2. When a car is 'catless' the smell of the exhaust is quite distinctive because it is a much more pungent smell due to the cat not being there to do it's job.

$10,000 fine last time I checked


Exactly.
And around here where i live if the cops want to defect your car they take it to a workshop and completely go over it.
This happened to me with my last car(a stock 1992 Lancer,) they didnt defect me for anything, but went over it for an hour.

[unluvedboi]

yes
yes and yes!

[Benji]

we don't have the same defect probs in bris, I've never been defected (even with my last car and it was very loud, some ppl said it was too loud), however my car dosn't stand out too much and i don't hang around the hoons in big groups which the cops target.

[LSD Motorsports]

Not nessessarily, but very illegal.
Very illegal yes, but the odds of getting caught are very small man. Im not sure how well the police are trained out there or how picky they are about fixed up cars, but this is really something that is almost impossible to detect and they have better things to do then bend under our rice rockets and lay on the floor only to say " i wonder if thats a hollow cat, let me get my saw out"
Haha, so have fun mate

[kousoku]

bs mate, easyest thing in the world to know.
goto the drags and walk behind each car, the ones that smell strange, either no cat, or hollowed out.
cops aint that dumb man, i'm sure if they wanted to know they would find out, and fine you.

not worth the 10k fine.
bad for the environment too.

[Felix]

bs mate, easyest thing in the world to know.
goto the drags and walk behind each car, the ones that smell strange, either no cat, or hollowed out.
cops aint that dumb man, i'm sure if they wanted to know they would find out, and fine you.

not worth the 10k fine.
bad for the environment too.

Exactly the Smell is a dead give away. When they checked over my lancer the cop mechanic put it on a hoist, and was running the engine and checking my whole exhaust system for holes. And it was a stock exhaust. They would notice if there was no cat due to the lack of heat on the outside of the Cat and the awful smell you have.
Trust me, once youve smelt the fumes from a car with no cat u can pick them as they drive past you in the streets. I know this due to my mates car temporarily had no Cat convertor.

[Benji]

ok, well i noticed no unusual smell when i had mine fitted, and nobody incl mechanics picked it up till the exhaust was off to replace the turbo. even mitsubishi dealer said nothin.

[Limbo]

Depends if they are looking to see if you have a cat or not. Most cars will have a very distinct smell, when my cat died and the bits fell out of it you could smell it . It smell alot richer. Also noadays if they are not sure and if your car is loud they send you for EPA testing and if you don't have a cat when they test you then your really F$&#^#.

The heat thing isn't really that detectable as most of your exhaust is pretty hot.