Anybody running without their cats?
Thread Starter
Pro
Joined: May 2003
Posts: 671
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From: WATERFORD CT
Anybody running without their cats?
Just wondering if anyone is doing this, How loud? Where can I find a straight pipe to replace the cat in my 85? Or is this just a bad idea all together?
Melting Slicks
Joined: Apr 2002
Posts: 2,546
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From: Orlando FL
Re: Anybody running without their cats? (montie98)
All you need to do is drop down the exhaust system and hammer out all the stuff inside. Thats what i did to mine.. Changed the exhaust tone a little bit.. Louder!! :) I really like the sound. Eventually, when i switch over to headers, i plan to run true duals out the back with flowmaster 40 series mufflers.. But until then, i like my free high flow cat heh :jester
Team Owner
Joined: Dec 2000
Posts: 21,094
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From: Phila., PA burbs
Re: Anybody running without their cats? (montie98)
I've had my center cat hollowed for about two years with no problems and have had a front y-pipe w/out precats for a year or so. It didn't really seem to make the car that much louder, but just gave it a deeper, more throaty tone. Some will tell you there is no performance gaing by eliminating the cats, but I can tell you that it definitly made a difference in my car. :yesnod:
Melting Slicks
Joined: Jan 2003
Posts: 2,167
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From: What did the 5 fingers say to the face? SLAP!!
Re: Anybody running without their cats? (montie98)
I have a piece of 3" straight pipe running through the case of my hollowed out main cat. My car is way louder and deeper than before. I never set off car alarms before I gutted the cat.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: Anybody running without their cats? (montie98)
Your '85 and my '84 had similar exhaust systems. They both had a single, center cat with no pre-cats. The biggest difference I've noted between the two exh systs, was the my cat is (was) flanged at both ends, like yours is in the rear. After becoming severly plugged, I gutted mine. The sound difference is more noticable outside the car than in. It is just a little louder and throatier. There is no steady speed drone. I have stock mufflers. My car still passes a smog test. Good luck, and...
RACE ON!!!
1984 Crossfire
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RACE ON!!!
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Instructor
Joined: Apr 2002
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From: Delanson NY
Re: Anybody running without their cats? (montie98)
Did the same as some of the others with my 89. Full length headers took care of the primary cats and I gutted out the secondary, still looks like you are utilizing the cat even though it is empty. As for sound, not too sure, did the entire exhaust all at once. New headers, cleaned out the cat along with flowmaster mufflers. I think it sounds great as do many others who hear me both coming and going. I think you'll like it!!!
Good Luck!
FRED
Good Luck!
FRED
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Re: Anybody running without their cats? (ONEBAD89)
As long as emission aren't a problem I say go for it. But I would recommend sleeving it. Some people don't, some do. Some say it is better flowing because of no expansion of chamber back into the pipe to ruin flow, some say that way particles can't get in the system. I don't know what's true, but I'd say sleeve it. :thumbs:
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Verdad Gallardo
Pro
Joined: Feb 2003
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From: anderson sc
Re: Anybody running without their cats? (redvetteC4)
i chopped mine. glad i did too, those things were HEAVY. it sounds the same, i have stock exhaust. but you can tell it breathes a little better at WOT. other than that your just opening her up a little. no codes either!!! :cheers:
Race Director
Joined: Dec 1999
Posts: 11,813
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From: Work
St. Jude Donor '09
Re: Anybody running without their cats? (USAsOnlyWay)
As long as emission aren't a problem I say go for it. But I would recommend sleeving it. Some people don't, some do. Some say it is better flowing because of no expansion of chamber back into the pipe to ruin flow, some say that way particles can't get in the system. I don't know what's true, but I'd say sleeve it. :thumbs: