High Flow Cat Or Not?

[chalky]

hey guys.Prob a dumb question..... In the end what would make more power?? A high flow cat or no cat at all?

[TiTAN]

a quality high flow cat and no cat will give very similar results.

[geraus]

No cat at all more flow but wont make that much power..mayb just a little bit

[chalky]

yeah im not expecting noticalbe power from the cat but on the dyno NO cat would show up a slightly larger power figure than a high flow?

[TiTAN]

a small difference. less than 5kw.

is that 5kw worth the defect/epa fine?

[chalky]

no its not. i run a high flow cat on street but was just curious

[geraus]

mines bashed out , i got i tuned when it was bashed out, it sounded a bit louder and gained mayb a little tiny bit of kws but its not worth having an EPA and stuff like that. Im gona chuck on back my CATCO highflow cat.

[chalky]

is a standard cat without any guts as good as a high flow?

[TiTAN]

no. as it is a much smaller pipe.

[Dose Pipe Sutututu]

when dyno tuning and dyno running, better without cat, this will deliver a more accurate A/F ratio as all tuners run the WB O2 using an exhaust sniffer rather than mounting it in the dump, pre cat where the cat doesn't affect the reading.

And yes, more power, with cats, once they're hot they become a restriction.

[Johnny]

No cat is better, can run a straight pipe with the stock cat plate welded on so no1 notices; simply swap to compliance cat if you need an EPA. A regular RWC mechanic wont notice it either.

if you are paranoid n wanna play it right, seems those 5inch body high flow metal cats are the answer; not cheap though. Probably wont pass EPA either so better jst run the straight pipe n swap it to compliance when u need to get tested.....enjoy the flames also lolz

[Binofski]

Hey sorry to hijack this thread a bit but what sort of power gain do you think i would see converting from a standard cat (2.5 inch inlet / outlet modified to fit 3 inch) to a highflow cat? Note I currently have a full split dump / front pipe which is 3' and the rest of the exhaust (excluding cat) is 3' aswell.

[Bakes]

I had no cat for a while, couldnt stand the fumes, headache material.

I put a Metal Cat 3.5 inch 100 cell cat back into my system and I love it. The horrible fumes are gone. The exhaust no longer stinks out the garage and I lost zero power when it went in. Response even improved when it went in and ECU got retuned.

[Basti]

Hey sorry to hijack this thread a bit but what sort of power gain do you think i would see converting from a standard cat (2.5 inch inlet / outlet modified to fit 3 inch) to a highflow cat? Note I currently have a full split dump / front pipe which is 3' and the rest of the exhaust (excluding cat) is 3' aswell.

a fair bit. cat is the biggest restriction in your exhaust, then dump, and lastly catback. you've gone about it backwards like i did.

[Binofski]

a fair bit. cat is the biggest restriction in your exhaust, then dump, and lastly catback. you've gone about it backwards like i did.

Yeh bought it from a guy who said it was a catless system... Got home bolted it up n realised there was a gap which matched where the cat would be

So yeh just on the cheap atm... so am waiting for one to come up.

[ARETHT3]

sorry just reading this and wondering... so if i wasa to purchase one would i need to get a retune or and will i still fell improvement if i wasnt to get it tuned

[Aberax]

Can get a retune if you want, but no real need, and yes, you should notice a slight improvement even if you don't get it tuned.

Edited September 30, 2009 by Aberax

[adamskill]

depending on what state you are in, the fine for not having a catalytic converter on a street car can be up to $10,000.

if your chasing 1 or 2kw by running a decat pipe, is it really worth the fine? if u want to make more power, dont f**k around with cats, get your engine built, better turbo, deacent ecu, and a good tune.

[Aberax]

depending on what state you are in, the fine for not having a catalytic converter on a street car can be up to $10,000.

if your chasing 1 or 2kw by running a decat pipe, is it really worth the fine? if u want to make more power, dont f**k around with cats, get your engine built, better turbo, deacent ecu, and a good tune.

+1

Also with decat/bashed cats, on a white car you get brown stains/marks on the rear bar.

[R33NUTTER]

but. the flames?

seriously though its not worth it ey, if all you get out of it is some flames and a non-noticable power increase.

if you got the car with an exhaust already wouldnt bother stuffin around man, if it were completely stock on the other hand, would get a whole new turbo back.