Need real answer: Does removing the cat's increase power?
Thread Starter
Le Mans Master
Joined: May 2000
Posts: 6,032
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From: Dallas TX
Need real answer: Does removing the cat's increase power?
On a normally modded C5, the usual bolt-ons: intake, headers, exhaust? Several people say yes, several others have said no, even some say you lose power/torque.
Where's the beef? :confused: :confused:
Where's the beef? :confused: :confused:
Race Director
Joined: Sep 2000
Posts: 11,309
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From: Valley Ranch, Texas
Re: Need real answer: Does removing the cat's increase power? (QUIKAG)
My experience has been you gain ZERO horsepower (sometimes even lose HP), but that you pick up good torque. My vert, with H/C package and LT headers, picked up 0.5 (yes, that's 1/2 - half) HP, but gained 15 TQ when we took the cats off. Did the dyno the same day, on the same dyno, within hours. :cheers:
Race Director
Joined: Sep 2000
Posts: 11,309
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From: Valley Ranch, Texas
Re: Need real answer: Does removing the cat's increase power? (QUIKAG)
Would you guys remove the cats if you had to do it all over again? :confused:
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Melting Slicks
Joined: Dec 2000
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From: Bethlehem PA
St. Jude Donor '03-'05-'06-'08-'10
Re: Need real answer: Does removing the cat's increase power? (bparker)
Improved by 10RWHP/10RWT on my H/C car. I have FLPs and removing them is a ten minute joob, so I take them out for racing only.
Joe
Joe
Le Mans Master
Joined: Dec 1999
Posts: 5,169
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From: Greenville SC
Re: Need real answer: Does removing the cat's increase power? (Mitch Alsup)
Anyone with a sense of social responsibility will take the 1% power loss and live with the cats.
Sarcasm off.
Reality: A few gearheads yanking their cats to squeeze 5-10 hp aren't going to make any difference in the world's air. You want to clean up the air, plant a tree and get on your congressperson to start making POWER COMPANIES and INDUSTRY stop polluting so much.
I - to this day - still don't know how WE, the people, got saddled with the burden of cleaning the air by having our cars so squeaky clean while big business seems to have gotten off scot-free.
Former Vendor
Joined: Nov 2000
Posts: 5,607
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From: Houston TX
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
On my previous bolt-on's and cam car, I lost about 5rwhp/tq with the cats off. But on bigger motor, you will definitely pick up anywhere from 15-25rwhp/tq. I have seen several dynographs on this. :cheers:
Race Director
Joined: Aug 2002
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From: Redacted
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
With all due respect Tom, you are FOS.
A car with removed cats pollutes as much as 100 cars with them working. The rules are the same for everyone, even hot-rod freaks. You cannot take them off legally and there's not that much to gain any way. You'd have to tune out for the O2 sensors and a bunch of other stuff in the process, so it just ain't worth it for a street driver.
Even SUV's and Trucks have to have cats and have to meet most of the same emission standards as everyone else.
Even diesels have cats today.
So don't take them off. If you want a car without cats, get a classic that never had them in the first place.
If you ever go to any major city at rush hour, you'll see exactly why our cars are burdened with pollution controls. There's millions and millions of them on the road.
A car with removed cats pollutes as much as 100 cars with them working. The rules are the same for everyone, even hot-rod freaks. You cannot take them off legally and there's not that much to gain any way. You'd have to tune out for the O2 sensors and a bunch of other stuff in the process, so it just ain't worth it for a street driver.
Even SUV's and Trucks have to have cats and have to meet most of the same emission standards as everyone else.
Even diesels have cats today.
So don't take them off. If you want a car without cats, get a classic that never had them in the first place.
If you ever go to any major city at rush hour, you'll see exactly why our cars are burdened with pollution controls. There's millions and millions of them on the road.
Instructor
Joined: May 2002
Posts: 116
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From: Plano TX
Re: Need real answer: Does removing the cat's increase power? (Sparticus)
How much better or worse will it sound w/ or w/out the cats? I just ordered a cam, long tubes, and a x-pipe and Im considering taking off the cats if it doesnt sound good enough.
Le Mans Master
Joined: Dec 1999
Posts: 5,169
Likes: 6
From: Greenville SC
Re: Need real answer: Does removing the cat's increase power? (larrysb)
With all due respect Tom, you are FOS.
A car with removed cats pollutes as much as 100 cars with them working.
Add to that, most Corvette owners drive there cars about HALF as much as the average SUV out there, and get about TWICE the mileage.
Then consider that production on the C5 Corvette is ~35,000 per year.
We could all gut our cats, and still pollute less than the SUVs.
The rules are the same for everyone, even hot-rod freaks.
Diesels don't put out as much HC's and NOx as gasoline engines to begin with, and don't benefit nearly as much from the cats as gasoline engines. But they put out a fair amount of particulate pollution.
Even SUV's and Trucks have to have cats and have to meet most of the same emission standards as everyone else.
"Not only do SUVs look like trucks, they pollute like trucks. SUVs are freed from fuel emissions standards that most cars have to meet. Minivans and SUVs spew 30 percent more carbon monoxide and hydrocarbons and 75 percent more nitrogen oxides in the air than passenger cars. They also guzzle gasoline. The new super-size Ford Excursion, for example, gets about 12 miles per gallon. As a result, overall fuel economy for all passenger vehicles is at its lowest since 1980. "
http://speakout.com/activism/issue_briefs/1258b-1.html
"Most SUVs and pickups, and all vans, are permitted to emit 29% to 47% more carbon monoxide (CO) and 75% to 175% more nitrogen oxides (NOx) than passenger cars. "
http://www.idontcareaboutair.com/facts/emissions.shtml
If you want a car without cats, get a classic that never had them in the first place.
:crazy:
[Modified by Tom Steele, 8:17 PM 12/11/2002]
Team Owner
Joined: Apr 2001
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From: S.W. Ohio. . . . . . NRA Life Member
Re: Need real answer: Does removing the cat's increase power? (YoBro)
Anyone with a sense of social responsibility will take the 1% power loss and live with the cats.
[Modified by Mike Mercury, 9:18 PM 12/11/2002]
Burning Brakes
Joined: Aug 2001
Posts: 1,206
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From: Roswell GA
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
Hello Tom Steele again. I do not even know you, but I have seen many of your posts, and....
Everytime you post you use up large portions of the page quoting other people and directly confronting their opinions. I would suggest that you just clearly and concisely state your position on the subject and leave it at that.
I am not sure of any of your actual positions on things, only that you find excessive faults in others opinions. So in a purely defensive positioning I am not stating any opinions on this topic. :blueangel:
Everytime you post you use up large portions of the page quoting other people and directly confronting their opinions. I would suggest that you just clearly and concisely state your position on the subject and leave it at that.
I am not sure of any of your actual positions on things, only that you find excessive faults in others opinions. So in a purely defensive positioning I am not stating any opinions on this topic. :blueangel:
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
I never failed to pass with past vehicles with cats removed/gutted here in FL when they tested. In fact, I was sometimes near equal in emmissions to cat equipped. Mind you these were well tuned vehicles. So I cannot agree in the 100 times pollution. Maybe for an oil burner out of tune.
My cat's are gutted and I did see increased power, but there are enough high-perf. cats out there that will give you lower restriction and still be legal.
I have a pair to install next time I have the exhaust apart. (but I love the sound the way it is! :cheers:
My cat's are gutted and I did see increased power, but there are enough high-perf. cats out there that will give you lower restriction and still be legal.
I have a pair to install next time I have the exhaust apart. (but I love the sound the way it is! :cheers:
Safety Car
Joined: Jul 2001
Posts: 3,667
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From: TurtleCreek Twp Ohio
Cruise-In III Veteran
Re: Need real answer: Does removing the cat's increase power? (QUIKAG)
:U
In an effort to get this thread back on track :rolleyes:
Quickag, I have sen a few bolt on LS1's dyno before and after cats and the gain is small, almost negligable. Sully dyno'd before and after with his C5R engine and I think he said it was 5rwhp? maybe he'll pipe in here, so he decided to keep his cats.
If I were you I'd keep them. I'm keeping mine.
On a normally modded C5, the usual bolt-ons: intake, headers, exhaust? Several people say yes, several others have said no, even some say you lose power/torque.
Quickag, I have sen a few bolt on LS1's dyno before and after cats and the gain is small, almost negligable. Sully dyno'd before and after with his C5R engine and I think he said it was 5rwhp? maybe he'll pipe in here, so he decided to keep his cats.
If I were you I'd keep them. I'm keeping mine.