removing cat. converter
Thread Starter
Drifting
Joined: Mar 2004
Posts: 1,764
Likes: 0
From: Warren MI
removing cat. converter
I was just wondering how many of you have removed your converter completly & how does your car run without it. Being from MICH I can take mine off & not worry about emissions testing.
:smash:
:smash:
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: removing cat. converter (Red_Vette_93)
Why bother? If your current cats are clogged now and you can't afford to replace them I can see it. If you're installing headers and can't afford to put new ones on it I can see it.
Removing a perfectly working cat from a perfectly working car just doesn't make any sense. There MIGHT be 5 horsepower to be had out of it, hardly worth the effort.
The myth that cats rob a lot of horsepower is just that, a myth. Take a late 70's, early 80's car that was loaded down with emissions equipment and doesn't run for crap. Rip all the emissions off of it and you still have an engine that doesn't run for crap. The reason is very mild cams, restrictive air intakes and poor cylinder heads along with crappy compression ratio's, not emissions equipment. Look at the power the Z06 is making and tell me that your cats are really costing you horsepower. It's in the cylinder heads, cam, & combustion chamber, not emissions.
Removing a perfectly working cat from a perfectly working car just doesn't make any sense. There MIGHT be 5 horsepower to be had out of it, hardly worth the effort.
The myth that cats rob a lot of horsepower is just that, a myth. Take a late 70's, early 80's car that was loaded down with emissions equipment and doesn't run for crap. Rip all the emissions off of it and you still have an engine that doesn't run for crap. The reason is very mild cams, restrictive air intakes and poor cylinder heads along with crappy compression ratio's, not emissions equipment. Look at the power the Z06 is making and tell me that your cats are really costing you horsepower. It's in the cylinder heads, cam, & combustion chamber, not emissions.
Safety Car
Joined: Aug 2002
Posts: 4,812
Likes: 1
From: New Albany IN
St. Jude Donor '03-'04-'06-'08-'09
Re: removing cat. converter (Nathan Plemons)
Plus the cats add a little "backpressure" which equals some seat-of-the-pants torque and acceleration. You may not notice a difference at all if you remove them but you should at leat HEAR the difference.
Safety Car
Joined: Feb 2001
Posts: 4,397
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From: Looks like I picked the wrong week to stop sniffin glue Orlando
Re: removing cat. converter (VictorRussell'92)
Yes and the car is much much happier. :yesnod:
I removed them because the pre-cats baked my feet when I lived in Hawaii, and the main-cat just helps cook the transmission. Over all the entire car stays much cooler without them.
:cheers:
[Modified by IBEAM700, 1:30 PM 3/31/2004]
Racer
Joined: Feb 2004
Posts: 445
Likes: 1
From: Atlanta GA
Re: removing cat. converter (IBEAM700)
According to Mac Performance Online, their 3" off-road test pipe (which installs in the place of the converter) nets a 5.4 horsepower gain.
Now that the performance issue has been addressed, what really matters, is your preference for the sound of the exhaust. Removing the cat will make the exhaust considerably lounder (hence magnifying interior resonance). If you're looking for a setup that really SCREAMS, toss the cat., lose the precats, and buy a set of Borla Stingers. Just installed the same setup on my 89 and it is a scorcher!!
Now that the performance issue has been addressed, what really matters, is your preference for the sound of the exhaust. Removing the cat will make the exhaust considerably lounder (hence magnifying interior resonance). If you're looking for a setup that really SCREAMS, toss the cat., lose the precats, and buy a set of Borla Stingers. Just installed the same setup on my 89 and it is a scorcher!!
Thread Starter
Drifting
Joined: Mar 2004
Posts: 1,764
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From: Warren MI
Re: removing cat. converter (Midnight89)
I assume the setup is pretty much the same for all C4's? I didn't know there were pre-cats & a cat. I tell you what ever happened to headers, exhaust, and mufflers??
:smash: :smash: ;)
:smash: :smash: ;)
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Team Owner
Joined: Sep 2003
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From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Re: removing cat. converter (Red_Vette_93)
I assume the setup is pretty much the same for all C4's? I didn't know there were pre-cats & a cat. I tell you what ever happened to headers, exhaust, and mufflers??
:smash: :smash: ;)
:smash: :smash: ;)
Heel & Toe
Joined: Dec 2003
Posts: 15
Likes: 0
From: Norman OK
Re: removing cat. converter (VictorRussell'92)
I was thinking about doing the same thing to my '96 LT4, but i was wondering if i would throw a code, if the cats are taken off, would i need to replace the O2 simulators?
Safety Car
Joined: Feb 2001
Posts: 4,397
Likes: 0
From: Looks like I picked the wrong week to stop sniffin glue Orlando
Re: removing cat. converter (torchredlt4)
The O2's in front of the cats remain stock. The O2's behind the cats get replaced with the Sim's :yesnod: :cheers:
Le Mans Master
Joined: Mar 2001
Posts: 9,464
Likes: 1
From: Modesto CA
Re: removing cat. converter (oldace84)
On my vette, I took off the converter, just to see if it'd make a difference...in sound, it sure as hell did! But I'm not so sure it made a noticeable difference in performance, however my wallet still weighs the same (as in, I didn't fork over $100 for a new high flow cat...yet)
Drifting
Joined: Aug 2000
Posts: 1,251
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Re: removing cat. converter (TIMSPEED)
I just replaced my Cat for emmissions reasons.I havent retested yet,when I do I'll tell the long story,but for now,
I didnt notice a loss of power,I blew off a 5.0 Mustang just punching it in O.D.
I did notice its quiter.I didnt need that.
But what I found interesting is,The mechanic pointed one of those temp guages you just point the red light at.The exhaust pipe in front of the Cat read 380 degrees,& behind the Cat only 100 degrees.
I didnt notice a loss of power,I blew off a 5.0 Mustang just punching it in O.D.
I did notice its quiter.I didnt need that.
But what I found interesting is,The mechanic pointed one of those temp guages you just point the red light at.The exhaust pipe in front of the Cat read 380 degrees,& behind the Cat only 100 degrees.
