gutting cat?

[i.c.]

theres this guy with a civic with a "gutted cat?" i think that's what it is....it had a stock exaust on it but that was no stock exaust....it sounded like a civic going through a tunnel? anyway....i was wondering if this is a real mod or is there something i can do for pretty cheap to make my car sound a little less weak...thank :)

[Justin86]

gut that cat or run straigt pipe, and cut the muffler off. This is the first thing I did and it sounds bad ass. :D

[i.c.]

gut that cat or run straigt pipe, and cut the muffler off. This is the first thing I did and it sounds bad ass. :D


how do you gut the cat?

[shepherd79]

remove the cat, and get some kind rod and start chipping stuff sway.

[i.c.]

remove the cat, and get some kind rod and start chipping stuff sway.


that's it?

cool....is it just bolted in...i'm trying to get an idea of what kind of job that is :)

[ivanfbi]

don't forget to get same one to pass emisions

[i.c.]

emissions? we don't have that in sc...everybody with a modded car around here either has strait pipes or side pipes

[88accordhb]

ummmm well taking the cat off, the only hard part is taking the rusted nuts off, first you gotta take the heat shield off, there's 2 pieces for the heat shield and like bout 6 nuts, then the cat is revealed, there are 3 bolts w/3 nuts on each end of the cat, those and the heat shield bolts are usually rusted as hell, you'll need bolt loosener, though i didn't just used a breaker bar. after you get the nuts off, dont try to hammer the bolt out of the cat, it wont go since they are welded on. you'll have to use a shit load of force, bend the exhaust pipe to where the bolts are free and the cat will come right off. wat i did was, on one end of the pipe there were some rusted nuts on the pipe, i used a ratchet on the nut to bend the pipe a little just enuff for the cat to come out. the book says you have to support the frexpipe with wires and junk becuz a hanging flexpipe might have enuff force to crack the header, which i doubt since they're cast iron, impossible to break. now, just do wat shepperd says, take a hammer and rod and bang the shit out of the honeycombs. when you put the cat back on, the nut tightening specs are 22 ft lb, but don't worry bout it just make sure you tighten it hella hard that it wont fall off. although i've hearb people say that gutted cats will have turbulance making the car rattle or comecrap. i'd go witha test pipe but good luck with wat ever you chose to do. and as always have fun. oh btw: dont even bother putting the heat shield back on, it's not all that usefull.

[cahil_1]

strait pipe it you'll feel so much better afterwards.

[P|eszczoH]

btw: dont even bother putting the heat shield back on, it's not all that usefull.


get Your car Hot, I mean verry hot, like one or two hour driving, and than put it on a dry grass and watch it burns.
I would say it can be usefull.
see Ya

[Robs89LXi]

Keep the heat shields. They are there for a very good reason.

[PortugalFocus]

Keep the heat shields. They are there for a very good reason.

I agree heat shields are there for a reason.

Steps to gutting a cat:
1 : remove cat
2 : root around in there with a stick until you can see through side to side
3 : reinstall cat

[Mike's89AccordLX]

If you gut the cat don't bother to put the heat sheilds back on. I've had my straight pipe on for over a year and I don't have any heat sheilds under my car. If you think about it the cat won't need heat sheilds anymore since it won't get as hot as it used to when it had all the honey comb stuff in it. When you don't have the honey comb stuff in the cat it won't get as hot as it used to. Believe me I have driven and parked on grass with my straight pipe and no sheilds.

[P|eszczoH]

Believe me I have driven and parked on grass with my straight pipe and no sheilds.

empty cat is a little bit thiner than a straight pipe, also its made with a little bit different materials, and it gets hot maybe not like a full cat, but stil hot.
I would keep it as long as it is not a straight pipe. But You dont have to just be careful and everything will be alright.
Good luck.

[k-roy]

emissions? we don't have that in sc...everybody with a modded car around here either has strait pipes or side pipes
Man this is a bueatiful state.

[Mike's89AccordLX]

Put it this way have you guys measured with a temp gun the heat of the exhaust? I have done this in school on a cat. only gets really hot b/c of all the honey comb pieces inside made of all kinds of precious metals. Without that stuff in there it won't get as hot as a regular cat and will have the same heat range as the rest of the exhaust system. I've tested my prelude and my accord. My accord exhaust down pipe was 175 deg. at one point and then I with the gutted cat it was the same. When I put my straight pipe on I re-tested it and the results were the same but this time the entire exhaust system was 200 deg.

Put it this way I have tested it so I know what it does and doesn't do. If the regular exhaust piping gets so hot then why isn't there a heat sheild on the muffler, down pipe, and the rest of the exhaust system. That's why there's only a heat sheild on the cat (and header if you want to be picky) b/c of all that honey comb stuff makes the cat so hot b/c it's oxidizing unburned fuel so it's burning unburned fuel and that's what causes the extra heat. So if you bust that crap out then it wont oxidize the unburned fuel and the heat will be the same as the rest of the exhaust system.

-Mike

If this doesn't prove that I'm right I guess you guys just need to try it and test it like I did and take a college class like I did on emissions systems so you can understand it better.

[88accordhb]

yes, i was gonna say that, all that! lol jk, but yah...with the honey comb inside the heat is squeezed thru, and the friction caused by the freeflowing heat, let's imagine, "molecules" hittin and stopping, then squieezed thru the honeycombs will cause lots of heat. without it, the heat is free to flow right thru.

[Vinny]

I had my cats gutted on my old chevy pickup. They lined the bottom eith lead so if they ever inspectd it and tapped on the bottom they didn't sound hollow. They used an air hammer to break all the crap out of them

[smufguy]

Put it this way I have tested it so I know what it does and doesn't do. If the regular exhaust piping gets so hot then why isn't there a heat sheild on the muffler, down pipe, and the rest of the exhaust system. That's why there's only a heat sheild on the cat (and header if you want to be picky) b/c of all that honey comb stuff makes the cat so hot b/c it's oxidizing unburned fuel so it's burning unburned fuel and that's what causes the extra heat. So if you bust that crap out then it wont oxidize the unburned fuel and the heat will be the same as the rest of the exhaust system.

We all know why and what the honeycomb is inside a cat, its the catalyst. But the reason the cat has a heat shield is different. The heat shield traps the heat in and prevents heat radiation. This concentrates the heat buildup in a control environement. THe catalytic converter needs to operate under hot temperature and a lil bit rich exhaust gas to work its full efficiency. Thats why your emission readings are off the scale at cold start than compared to ur reading after 5 minutes of driving. Its not that the honey comb stuff makes it too hot, its the heatshield that is around it makes the cat operate better. no matter if u gut the cat or not, the heat is the same, since there is heat loss due to dissipation from the header, downpipe, catback and muffler, the temperature of the gas coming out of the tip, is not the same as the temp of the gas coming out of the header.

[88accordhb]

who the hell cares about radiation and pollution besides the government? lol jk.

[smufguy]

who the hell cares about radiation and pollution besides the government? lol jk.

heat loss due to radiation lowers ur exhaust gas velocity fella ;) which u dont want do you, do you, do you, do you??? :tongue:

[Justin86]

heat sheild's, we don't need no stinking heat sheild's. The only reason a cat get hot is cause of the after burrning process of the fuels. If you gut the cat that process won't happen and it won't get that hot, so no reason for the sheild. Also how many of use actually park on dry grass. Come on I want to see a show of hands here, cause I park on pavemant.

[88accordhb]

heat loss due to radiation lowers ur exhaust gas velocity fella ;) which u dont want do you, do you, do you, do you??? :tongue:
wth do i want my gas to go fast for?

[88accordhb]

oh btw: this doest belong in the performance section, because it won't give you any hp. unless sound belongs in performance.

[Justin86]

oh btw: this doest belong in the performance section, because it won't give you any hp. unless sound belongs in performance.
This is the point where I go :owned: :rice: :stupid: :kekeke: :uh: :idea: :repost: :crying: :bong: :beat:

[88ebrake]

im plannin on doin this myself does it sound better and will u see any hp gains

[300700'88lx-i]

Ahh, when two simultaneous threads on the same topic exsist in unison...... (http://3geez.com/showthread.php?t=34095)

[Justin86]

yea I have been aware of that crazy hair guy. AS for hp, I did it and it was a slug off the line but it did sound better and more agressive.

[smufguy]

oh btw: this doest belong in the performance section, because it won't give you any hp. unless sound belongs in performance.

You dont wanna know how many times i have told guys that gutting out the cat is not a performance. If you look at it, since the inside of the Catalytic converter is not a straight hollow tube, the eddy currents actually induce turbulance which is not needed for performance. Besides, the low growl is more of a resonance of the hollow cat IMO. So yeah, it sucks when ppl actually make up threads upon threads asking about that thing. also a how-to on gutting a cat??? thats a new one :rolleyes:

[88accordhb]

lol :rofl:

[88ebrake]

those fuckin bolts sre bitches i tried to put the beef to em and the wont budge and i cant get a cheater bar under there

[88accordhb]

hmmm, pray hella dd40 on that shit, use excessive force, that's your best bet. why can't you get a breaker bar down there? don't saw the bolts off, not worth it that's a waste of a good cat.