Pros and cons of Gutting cats?

[KW521]

This is a two part question. First of what are the pros and cons of gutting the cats? There is no emissons here in salem first off. Will my car get better gas mileage with them gutted? will it perform better and will it sound better? Im trying to get the boxer sound more out of my car and i have a flowmaster 40 series delta flow only axle back. Now if i do cat back will it bring out the sound more? ANd should i change the muffler? flowmaster=good for boxer sound or bad? i know borlas will do a world of work but i have single port and they are spendy. so cats being gutted good or bad? and cat back bring out more sound? keep flowmaster for muffler or change it for a better sounding one cause i know it has a lot to do with the muffler too. thanks.

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[east milford wrx]

if you take some time to search you will find everything you want.

[rougeben83]

Gutting your cats is pointless; you gain very little power if any, and the same can be said for your mpg as well.

The only thing you'll be doing is making the car louder and polluting the environment more.

I suppose the extra sound is what you want. :shrugs:

Bigger pipes and a freerer flowing muffler will make it sound louder if that's what you meant by "boxer sound".

[KW521]

so what rougeben your saying is a more open muffler will bring out the sound more? unlike my chambered flowmaster?
and just asking for people to try not to be biased on the whole gutting cats thing. i just want facts please? and i did use the wonderful search button and i couldnt find anything. since you all have been extremely helpful ill just keep asking you when i cant find it with searching.

[Rockgod]

KW521 take rougeben's advice on this. I did and it paid off for me. Three Cheers for rougeben83! lol Oh by the way Ben, Here's a clip of the borla setup I had done at RJ's custom piping. Thanks for the info on the place. I know where to go from now on. Edit: Car is not properly warmed up but you get the idea. Gonna have a better clip soon. http://s158.photobucket.com/albums/t...nt=MySubie.flv

[Rockgod]

oh yeah sorry about the background noise in the clip.

[rougeben83]

Nice sound rockgod, that's pretty mean! What else are you running? EDIT: did you go to RJ? They were straightforward and approached what I wanted out of the exhaust with a clear-cut, no bs answer - I would go back to them again even if I had to pay more than going to some other shop.

Flowmasters are good for sound, but more for bigger displacement engines; The chamber design tunes the exhaust pulses to sound "burbly" like a V8 w/ glasspacks IMO (at least from hearing it on different V6's, V8's, and someI4's)

There's two ways to approach what youre asking about; the "boxer rumble" and the volume of your exhaust. Going with the bigger pipes and free-flowing exhaust will increase the volume; it will bring out the "boxer rumble" that is already there with the stock headers.

To make the "rumble" more pronounced, you have to make the exhaust pulses more uneven, which is what the borla headers do, in addition to the slightly bigger pipes to the cat.

I stated the facts about gutting a cat. To me it's not worth it. The idea of gutting the cats only carried over from the 60's and 70's when auto manufacturers put all sort of emissions gear on those V8 cars to comply with suddenly stringent (for that time) emissions regs from the EPA. Catalytic converters back then were very restrictive and very inefficient, so you could pick up 15, 20, maybe even more hp from just gutting them on a SBC.

Cats nowadays are relatively free flowing, even the OEM ones that are not labeled "hi-flow"; you rarely pick up any power/mpg out of gutting it, and you only make more sound. To me this is not enough reason to dump more pollutants into the environment than there already is, but it's your choice.

A lot of people do it here in MI too, since there's no emissions testing, and it's of course free to do. I guess that's the appeal of it; the promise of "free" horsepower.

[Kraziken]

If you would like more engine rumble. Consider a Cold Air intake before the exhaust. I found modding the exhaust pleasing, but the CAI introduces a very loud roar at WOT.

[gtwagon941]

Borlas + HiFlow Cat + 2.25 Catback exhaust with Free flowing muff = the winnner.

running no cats=loser

.02

Jared

[Rockgod]

Amen to that GTW941. Thanks Ben. As for what I'm running with? Nothing except the Borla Headers and Pro XS Muffler with a High-flow cat. 2.25 pipes and NGK Iridium IX Spark Plugs with a K&N Filter. That's it I swear. I WISH I had more.

[DLC]

Borla + Random + Fujitsubo sounds really good, especially when the CEL goes away (pop pop pop on decel).

I'm somewhat apprehensive about what the TWE EL headers are going to make the exhaust sound like. I know it'll be different, but hopefully in a good way. (porsche please!)

[Rockgod]

I'm Happy with my setup as is but I really wanted that fujitsubo setup but damn can't find it here in NYC and when I did find online it was expensive. But worth it if I had the cash.

[Radeon]

Hehe, my wife just saw the title of this topic. She now thinks I hate cats.

[whoosh]

empty out cat

breath in dust

maybe die from cancer in 10-15 years

[Wiscon_Mark]

Originally Posted by Radeon

Hehe, my wife just saw the title of this topic. She now thinks I hate cats.

A hi-flow cat is the way to go if you want to touch 'em.

[KD7000]

Originally Posted by gtwagon941

HiFlow Cat = winner.

running no cats=loser

Simplified the math for ya.

[rougeben83]

[KW521]

ok cool i wont gut the cats thanks very much for that info.....now problem with the headers.....borla is the only company that makes single port headers right? and for the straight through muffler will any straight through muffler work or does it depend on brand?

[legacy1907]

Originally Posted by DLC

Borla + Random + Fujitsubo sounds really good, especially when the CEL goes away (pop pop pop on decel).

im sure thats similar to my borla+random+stromung which i think sounds bad ass

[KW521]

i hear a lot about stromung...and i have heard the exhaust. what makes theirs so great? muffler set up? cuase thats what im trying to find is a muffler to get the better sound with my exhaust

[rougeben83]

I think it's because it strikes the right balance between volume and sound; I've heard the full setup (EL headers, randomtech cat, fujitsubo catback w/ spicy cams), and you couldn't tell it wasn't stock from the idle, but it had a nice sound when you romped on it.

[DLC]

rougeben83: who has that setup with the EL/Random/Fujitsubo/Spicy cams? It's otherwise very, very similar to what I'm going to have soon.

[rougeben83]

Originally Posted by DLC

rougeben83: who has that setup with the EL/Random/Fujitsubo/Spicy cams? It's otherwise very, very similar to what I'm going to have soon.

It was an older fellow down in Columbus, OH, I bought my old Rota Tarmacs from him last summer. He had an 03 L Wagon in green with BBS's on as his daily driver. He has a NASIOC account but rarely uses it; I'll have to see if I still have his PM.

[Denver_97subie]

I find this thread interesting lol

[subaru_01]

removing cats are a good thing, though u are polluting the air. But with a tune car, removing the car will ease the gas peddle...and make the car a little less restrictive...