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would my car run like crap without a cat?


88CiViC_D-15
04-14-2005, 12:22 AM
hey everyone.
ok, i have been thinkin of runnin a custom exhaust when i put a turbo on my std manifold. but if i decide to run my car without a cat, would it run like crap or just the same. plus i dont have to worry about smogs, here where i live, only have to smog once and thats it till i sell her. thanx

civickiller
04-14-2005, 02:51 AM
keep your cat

clawhammer
04-14-2005, 07:15 AM
Why? I'm thinking of gutting my cat. There are no emmissions testing where I live, so that's not a problem.

4thgenracer
04-14-2005, 10:04 AM
it no big deal mine is gutted,all it does is make it louder

BLU CIVIC
04-14-2005, 11:25 AM
and louder means more police attraction...i'd get a test pipe instead of gutting ur cat b/c u may need it

Juicy05
04-14-2005, 02:39 PM
Smell like ass too

SiZ
04-14-2005, 03:27 PM
Ya, the noise is by far the worst factor of not having a cat. I never noticed a smell, and the car ran juuust fine.

clawhammer
04-14-2005, 06:52 PM
Well, I can live with the noise. More power as well, right?

BLU CIVIC
04-14-2005, 07:36 PM
More power as well, right?

no not really

clawhammer
04-14-2005, 09:02 PM
no not really
Wouldn't it help the engine breathe a little better, since it has a better flow? What about gas mileage? Would it go up or down?

civickiller
04-14-2005, 10:29 PM
dude if your so desperate for that 2whp it will give you. then idk what to say. destroying hte environment is not worth the 2whp youll get

Scott82
04-14-2005, 10:40 PM
there are far worse things you could do to the enviroment and far worse things that have been done to the enviroment. Cat or no cat the car should run pretty much the same. If you happen to have 2 o2 sensors which in your case i doubt that you have 2, but you could get a engine code for the o2 after the cat but other than that like they say it'll be louder. but if you don't care about how damn loud it'll be then it'll work.

Twyztidmind
04-16-2005, 12:29 AM
dude i took off my cat on my 240sx, and put on a test pipe and i noticed a huge diffrence. A cat is very restrictive have you ever looked into one of them things?

civickiller
04-16-2005, 02:52 AM
yeah but his 1.6 sohc compared to your 2.4 dohc is a big difference. the couple horses arent worth the damage to the environment. and its thinking like oh well its so little or everyone else does it or other people are doing far worse, is a poor way of thinking. just because other people do it, doesnt mean you ahve too

Kven
04-16-2005, 01:10 PM
turbo cars can use that less pressure. it really depends on many factors thatll determine how much youll gain. in most cases, it really is a big bottleneck. imo, its best to just get a high-flow cat. in most cases, gas mileage also goes down.

btw, it does stink. smells like a lawnmower to me.

also, im running a full mandrel cat-less exhaust.

Juicy05
04-16-2005, 01:43 PM
and after awhile your exhuast gets a whole shit load of carbon buildup, ten times worse than normal and spits black shit out of yoru exhuast........i get pissed

icE_x
04-16-2005, 01:50 PM
lol mine does that because it burns oil lol

BiGwiLLswiLLy
04-17-2005, 12:25 PM
well if u are runnin turbo then go no cat and bigger exhaust but if it you were runnin all motor then jus leave it cause u need the back pressure anyway, plus in a all motor car guttin the cat wouldent make a diffence...

Kven
04-17-2005, 01:02 PM
well if u are runnin turbo then go no cat and bigger exhaust but if it you were runnin all motor then jus leave it cause u need the back pressure anyway, plus in a all motor car guttin the cat wouldent make a diffence...

back pressure is bad in any setup. the word youre looking for is velocity(you want the exhaust gas to move as fast as it can without backing up/backpressure); i think it was stated above.

KinkBykr
04-17-2005, 08:01 PM
1)It makes your car stink
2)the tiny differnce is not worth putting that crap in the air
3)it's louder, so more tickets from cops saying your recklessly accelerating, belive me, happened to a friend

BUT if you insist there are valves that you can buy to put in your exahaust before the cat, but really, for the $$$ you would buy that for, eh, not worth it, use the couple bucks to buy something usefull

BiGwiLLswiLLy
04-18-2005, 10:36 PM
no backpressure is needed with out it N/A motors run like shit without it disconnect ur exhaust at the cat n drive you'll see it will move like a turtle...

Kven
04-19-2005, 02:22 AM
no backpressure is needed with out it N/A motors run like shit without it disconnect ur exhaust at the cat n drive you'll see it will move like a turtle...

do you understand the difference between backpressure and velocity? its proven that backpressure is bad for your engine; people remove their cats, which is obviously restrictive and creates some backpressure; and noticed some hp/torque freed. If there's any backpressure; the engine would have to work to move it out; while gas moving at high velocity will actually pull some gas out of the chamber(and pull some intake during overlap, aka scavenging). When you remove your exhaust, you have no or very slow gas velocity; and if you noticed lots of N/A cars with large pipes tend to lose low-end hp; due to decreased low-rpm velocity, while small pipes work good in the low rpm range but choke high-rpm power.

a perfect exhaust/header combo would have the highest gas velocity without causing pressure buildup/backpressure.

edit: found something that shows increase in backpressure(in this case, a cat) will make you lose some hp on a NA engines(not much HP loss, but its still result of increase resistance/backpressure, aso on this engine it started running lean with the introduction of the test pipe; so more fuel would need to be added; we all know more fuel=more power but decrease in MPG):http://hybrid2.honda-perf.org/tech/b20/dyno/mfscat.gif
This is on a B20Z, Magnaflow Street exhaust, Blue=with cat, Red=without.

BLU CIVIC
04-19-2005, 08:04 AM
no need to pull out the charts and graphs mr professor b/c the topic of backpressure has been discussed extensively...it all boils down to wether removing his cat is worth the extra 2hp or not...i still vote nay

Purplcivic
04-19-2005, 11:45 PM
mine doesnt have a cat, got no problems, 40 mpg on a straightpipe, smell - i dont smell shit, just gas, noise - not really too loud, engine breaths well - would you like to have a congested nose? Yes, there is a significant power increase.

Kven
04-20-2005, 02:33 AM
smell - i dont smell shit, just gas

thats the smell...

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