Jix01

alright so ive looked around and im almost ready for exhasut with one thing left to get opinions about. should i get the cat cut off or should i get a high flow cat? there are no emissions here but i heard without a cat you lose like 1 mile or two to the gallon but without a cat you gain about 5 HP?

formula_novice

iTrader: (1)

I would keep it. I've also heard it is only about a 5HP gain. You won't notice 5HP, so why waste the time... plus 5HP is a small price to pay for cleaner air

mouthforcombat

It's all preference... You can either have that small chunk of horsepower with a little bit better sounding exhaust, or you can have a little bit better of gas mileage and self satisfaction of polluting the air a little bit less.

I don't have a cat but that's because I sawed off my old system when I installed headers and they didn't put a cat on... Doesn't bother me any, I might as well enjoy a little freedom before the cars are altogether outlawed or something ridiculous along those lines.

Kevin91Z

iTrader: (1)

The law says you have to run a cat. By doing so you're keeping our air cleaner. By running without a cat you're giving the people driving behind you a reason to hate us hot rodders.

Cflick

Cats flow a whole lot better than some think. I run 'em, and always will, for a whole variety of reasons.

Stephen

iTrader: (12)

Even in a non-emissions area, your car is still required to have it's original equipment. IE: the cat...

Run a Magnaflow (highest flowing brand, AFAIK) & you won't notice 5hp (at most) loss. And you'll give the tree-huggers one less target/reason to bash the "hot rods".

Jix01

well looks like im going with a cat then thanks for the opinons guys

tonkpils1769

i was thinking about cutting mine off as well but after this im gonna stick with mine.

DCOWBOYS1975

Look I am from Battle Ground an I don't have to get emissions. I have an 83 Camaro and the CATS are gone. If everybody is trying to save the air talk to all the girls that use hairspray and all the other crap that ruins the air. FIVE HP MATTER. Any horsepower makes a faster car. If the air is what you are worried about you should have bought a Prius not a Chevy.

Stephen

iTrader: (12)

Well, this WAS a civil discussion, until you piped up....

A good high flow cat (not the 20 year old technology OEM style cats) wouldn't even cost you 5hp. For that matter, the old "butt dyno" won't notice 5hp anyways.

Regardless of emissions testing, by law the stuff has to remain. I live in a non-emissions county too, but would still fail inspection if the inspector looked, saw no cat & cared.

tonkpils1769

what about just hollowing out the CAT?

irocz28boy

iTrader: (2)

Wow, really? So you're saying any Chevy is bad for the environment?
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Same thing basically, but you would still be able to pass a visual inspection if you have testing.

tonkpils1769

yea there is no emissions where im from, but it would still be bad for the air.. If you want to pass a visual inspection i think that would be the best way

DCOWBOYS1975

I apologize if I offended anyone. I grew up in Oklahoma and was raised that anything that robs ANY horsepower should go. And I guess living in the Northwest as long as I have I get sick and tired of tree huggin hippies.

I apologize again if I have offended anybody, that is not what I intended to do.

Trey

Stephen

iTrader: (12)

Hollowing out a 20 yr old plugged cat,,,yes. It will help flow. A GOOD flowing cat? Not enough to make it worth the trouble to do.

A CHEAPO new cat? Maybe. I'm just sure 2008 basic technology is still better than the best 1990 technology, & flows better used than a 1990 did brand new.

Yes, GOOD cats aren't REAL cheap, but better than failing inspection & having spend the $ & time on a "illegal" set up PLUS the $ on redoing it with a cat, and having to do it within, 7 days I think here, to get it reinspected for "free", than having to pay for the inspection again later.

Do it right & do it once, is my philoposy.

tonkpils1769

well my cat is the original 1990 RS so i really wouldnt care about tearing it up for more flow and a little better sound.. i think MS is a little to poor to care about emmisions lol

91formulaSS

Not trying to hijack this thread but.............I was looking at a 3" Magnaflow cat and was wondering wheather to go with the "standard" or "spun metalic" type? does anyone know the difference? I need something that will scrub the exhaust really good since I'm going to try and eventually pass emissions with a carburated engine.

Jix01

BTW i never said i was worried about the air lol

DCOWBOYS1975

SO GET NAKED AND GET RID OF THE CATS!!! YEEEEEE HHAAAWWWW

Kevin91Z

iTrader: (1)

The standard cats are fine. The spun-metallic type are smaller bodies for tight locations, but there is plenty of room under our cars for a regular cat.

Cflick

What about things like seats ?

The power loss through a modern honycomb cat is just about zero.
Don't believe it ? Put one on a flow bench, and compare it to a straight piece of the same size pipe.

DCOWBOYS1975

Its a proven fact that CAT's rob hp. As far as robbin' HP that goes for a/c as well. Not much but some. SOME MATTERS.

Cflick

Not at all !

What's been proven is that an inadequate exhaust flow causes back pressure, increasing pumping losses, requiring a different intake mixture, and such, which "back in the day" before EFI could cause performance to drop.
It's known that the old obsolete pelet type converters could and would plug up and restrict exhaust flow. That much *is* historical fact.
A statement such as "Its a proven fact that CAT's rob hp." is patently false.
Remember, it was a "proven fact" that human beings can not survive a horseless carriage ride at speeds above 30 MPH, as we would suffocate and die.
Be careful with expressions like "proven" and "fact."
Show the flow numbers, and I might believe you for a particular cat under specific circumstances, but not as a blanket, all encompassing, statement.

GoodlookinRS

iTrader: (1)

i think it makes your car sound better with out the cat and go to autozone for 5 bucks and they make the flex pipe for it and so 5 more hp then you had. thats just me.
kevin

ccook-92-305

i couldnt even stand being behind my car when it had the cat on it. it smelled like sulfer something aweful. cheap fix cut it off and the people behind me didnt have watering eyes from the choking sulfer smell. none of that stuff does that much for our environment anyway. like the smog pump... that pumps air into the exhaust... doesnt make it better just dilutes the bad stuff so its not as concentrated.

if you're worried about being legal just take it off and run a broom handle through it till its hollow then you get the best of both worlds.

8T9 BANDIT

if any of you beleive that not running a cat in our cars is going to keep our air cleaner, then youre misinformed! that is a crock of ****. cars have little to no effect on " air pollution" . if you want to have an effect on pollution, go kill a bunch of cows in the mid west, because america's cows create more of the emmisions then all the cars on the road ( yes that is a fact), so if you want 5 more hp, and a better sounding muscle car, then yes, ditch the cats.
oh, and btw, global warming is bs too..

DCOWBOYS1975

I guess nothing is a "fact" per se but for the most part cat's rod horsepower. Whether it 1 or 5 hp it all matters to me. I bought a Camaro to be fast not environmentally sound. It all comes down to what you are looking for I guess.
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I agree with GoodlookinRS.
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AMEN BROTHER!!!

Cflick

Again, no.
That pump adds additional unreacted oxygen to the mix before the cat, so that the cat can properly burn off unburned ( wasted ) gas.
Your sulfer dioxide smell was from a problem, likely a defective cat, not because it was doing its job as it should.

JonBlaze

just a thought about the smog pump

if it's removed not only does it add horsepower but also fuel milage too

now if it add milage doesn't that mean better emissions?

GoodlookinRS

iTrader: (1)

Yep i took all that crap and i could tell a little difference in everything.
kevin

IROCNMIHEAD

So TRUE If you really want to save the earth get a Prius or Corolla, otherwise it shouldn't matter. But I run with a cat LMAO (Cant complain with free exhaust)

DCOWBOYS1975

Thank you IROC!!!!! Finally someone that agrees. Cut them things off you can get the peices to fix that problem for like $5. Some cuttin' and a couple welds and BAM you're done!!!!

GoodlookinRS

iTrader: (1)

At autozone they sell the flex pipe with clamps.
kevin

Stephen

iTrader: (12)

I'd love to make some direct comparisons. Anybody know a Prius or Corolla owner to get #s from, so we can compare?

I'll volunteer my "no smog pump, no AIR tube, 20 yr old technology, 170k mile 'gas guzzler' but with a cat, test results" as a comparison. Who's up for the challenge?

We can argue all day long, but with true #s to compare, it's useles to.

DCOWBOYS1975

Really who cares. If you want an "environmentally friendly" car then keep the cat's but... If you want a TRUE road peelin' Hot Rod rip the biatches out!!

Kinda like this.

Most men like boxers so a fella can breathe....I treat my car the same!!!

Stephen

iTrader: (12)

If a 2008 Corvette Z06 can be clean at 505hp, what's our excuse at 245hp?

Is my car so lame I hafta "play dirty" to compete?

DCOWBOYS1975

Brother you car is far from lame. And as far as a 2008 Vette. I would rather have an older one my self. Not big into newer cars. I know I am crazy. I would rather have a nice 78 25th Anniversary Vette( not cat's of course )

irocz28boy

iTrader: (2)

I can't believe this thread. I don't have any of the emissions stuff and I noticed no difference in power. I plan on putting everything back on as soon as possible.

DCOWBOYS1975

You ain't gonna notice from just one thing. It's not like you take out the emissions stuff and all the sudden you got 400 horsepower. But if you put all the "little" things you can remove or tweak then it does matter. It's like this, 10 things that can make you 2 horsepower that equal 20 horsepower. I am not arguing with anyone. I was just giving my opinion. My opinion is if you want to have a Hot Rod you will do everything possible to get more of an edge.

Trey

GoodlookinRS

iTrader: (1)

I'm right their with you man!
kevin

Stephen

iTrader: (12)

Slap NOS on. For the same $500, you can get 150hp, not 20!

I'd rather have a $50 bigger wallet than 2hp.....Like air foils...2-3hp?.....$50-ish parts. Only reason I have one, is because it was on the car already, when I bought the car. Do you have an air foil? There's 2hp!

Yes, I believe in stacking mods benefits on top of other mods too, but only to a point. Our TPIs are kinda limited in what they can achieve, without ruining gas mileage.

Having a no cat isn't worth running without one to get 2hp, to chance not passing inspection, then having x # of days to get it legal to pass (before having to pay for the inspection again).....having to rely on a friend to pass you, which btw, if it is discovered he did, he can lose his license, the station gets fined, then the station fires him because of that!

You want free hp? Start stripping parts off to reduce weight. Bumper reinforcements...Back seat....Trash....AC,,,,Heater.....Carpet....Air Bagsteering wheel (if your car has one)....Put in a LS1 plastic gas tank, instead of your steel tank....After all, it all adds up, right?

RicksIroc86

i agree if your looking to make your car faster and stack little things, try weight reduction. it helps alot more than cutting a cat out, ac and smog delete etc.

Rayzor32

iTrader: (1)

yeah delete the cat definetly along with all the other smog (air pump, egr, pvc, fuel canister) everyone i know always deletes all that crap, which is all it is is crap. its a proven fact that cats rob horsepower why do yous think people take them off?? all my friends are gearheads and been doing this **** for 30+ years. if your a tree hugger than you might wanna keep it on. ps i have no sulfer smell and my exhaust sounds way better.

IROCThe5.7L

Enough.

You're not going to feel any difference gutting your cat accept for the sound and smell. If you have a old partially clogged cat, then yes. Regardless it is illegal and you'd be better off with a nice high flow.