How many horses do you get out of removing Catalytic Converter??
02-01-2002, 11:20 PM
#2
Le Mans Master
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Re: How many horses do you get out of removing Catalytic Converter?? (gray84)
Just liek with almost any sports car, removing the cat IS worth it.. Can't claim HP numbers, but it makes sense that it should be at least a few tenths form jus tthat. BUT on the other hand you will fail emissions almost certainly.. Is it worth it? Lot of people just GUT the insides of it, so if they look underneath they still see the cat in place..
02-02-2002, 01:27 AM
#3
Drifting
Re: How many horses do you get out of removing Catalytic Converter?? (gray84)
Couldnt tell you but I bought my car in hawaii it had no cats , duels straight pipes all the way into a set of flowmaster muffs moved to Cali had to get a cat put on. I thought the car ran fine before it was kinda loud with the top down but sounded good. Well anyway I got it put on the car seem to be a little faster and ran smoother with it on. Mine runs a lot better with it on So I dont know????
02-02-2002, 01:31 AM
#4
Team Owner
Re: How many horses do you get out of removing Catalytic Converter?? (MrNuke)
. BUT on the other hand you will fail emissions almost certainly.. Is it worth it?
02-02-2002, 01:33 PM
#5
Race Director
Re: How many horses do you get out of removing Catalytic Converter?? (tntcorvette)
Absoultly ZERO gain!! Corvette fever did an articale on it many moons ago and actually lost 2 tenths without them! I'm not a huge enviromentalist, but if your car is running right, they wont hurt performance at all (in stock form)
02-02-2002, 02:03 PM
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Re: How many horses do you get out of removing Catalytic Converter?? (BluByU)
thats wierd.. most guys I speak to and some of my friend's gut their cats and show a few tenths better slips.. Although I am not referring to vettes. Mostly mustangs and few imports.. Maybe in our vettes the backpressure created by the cat helps a bit?
02-02-2002, 02:12 PM
#7
Team Owner
Well on my L98 I certaily did gain something.
Before Cat Removal: 13.89 @ 98.17
After Cat Removal (w/o traction): 13.9x @ 100.xx
After Cat Removal (w/ traction): 13.48 @ 101.11
I picked up a solid 2.25 mph at the same track that I ran the 13.89 at. I was getting junky 2.2 60' that day though, so I couldn't compare ET. Then at Englishtown with -489 foot sealevel conditions and a good hook (street tires) I ran the 13.48 @ 101.11.
Before Cat Removal: 13.89 @ 98.17
After Cat Removal (w/o traction): 13.9x @ 100.xx
After Cat Removal (w/ traction): 13.48 @ 101.11
I picked up a solid 2.25 mph at the same track that I ran the 13.89 at. I was getting junky 2.2 60' that day though, so I couldn't compare ET. Then at Englishtown with -489 foot sealevel conditions and a good hook (street tires) I ran the 13.48 @ 101.11.
02-02-2002, 02:23 PM
#8
Race Director
Re:
I would imagine that any cars that gains any power must mean the old pipes and cats were clogged or restrictive to begin with.Once gutted,the car feels so much alive again.Or replace with new pieces and it feels alive again.
A back to back testing with a free flow cat by random technologies showed a 5 HP difference between their cat and No cat at all,yet keeps the air cleaner.
They have some good cats on the market and they flow just as well as a gutted pipe.
I,however,like to keep the air somewhat clean.I had a busted cat and the exhaust was stinking with it too..replaced it with a new one and all is well.
Im not a tree hugger but seems the cars we drive get targeted first with strict epa BS and we need to beat them at their game.
If our old cars cant pass or word gets out that many owners are gutting emissions pipes and etc, they going to try and pass even stricter laws...will eventually catch up with us.Theyve been trying anyways eh?
Its more impressive to me to see a car with a cat make nice power then to see one without one make power.
At least have one good main cat on your C4...the precats dont seem to change emissions any and isnt needed.
:)
A back to back testing with a free flow cat by random technologies showed a 5 HP difference between their cat and No cat at all,yet keeps the air cleaner.
They have some good cats on the market and they flow just as well as a gutted pipe.
I,however,like to keep the air somewhat clean.I had a busted cat and the exhaust was stinking with it too..replaced it with a new one and all is well.
Im not a tree hugger but seems the cars we drive get targeted first with strict epa BS and we need to beat them at their game.
If our old cars cant pass or word gets out that many owners are gutting emissions pipes and etc, they going to try and pass even stricter laws...will eventually catch up with us.Theyve been trying anyways eh?
Its more impressive to me to see a car with a cat make nice power then to see one without one make power.
At least have one good main cat on your C4...the precats dont seem to change emissions any and isnt needed.
:)
02-02-2002, 03:16 PM
#9
Re: How many horses do you get out of removing Catalytic Converter?? (gray84)
There is a lot of info here that could be taken the wrong way. Let me say that if you are going to gut your cat or otherwise remove it yet keep your stock manifolds you are wasting your time. All you are doing is causing more polution for little or no gain if your cat is in working order.
If you remove your cats because you are installing headers, you'll certainly see an increase because the headers flow more than stock manifolds anyway.
Cats added horsepower, well let's just put that into the proper perspective shall we. These are brand new, high performance cats, meant for such an application. A brand new stock cat would NOT give you the same results. Also I'd love to see the actual dyno graphs for these claims. Sure it might add 5 horespower at the peak, but what does it do for the rest of the power curve? Without looking at the dyno graph, it's useless info. Peak numbers are crap, think of averages, and lets use a lightbulb example. If you have a box of 5 lightbulbs, 4 of them will blow out in 1 hour, the other one lasts 1,000,000 hours. The AVERAGE for the box is still 200,000 hours. The same thing works for PEAK numbers. Peaks and averages are useless unless you know more info.
I'm not trying to call anybody a liar here, but I'm just gonna say that I don't have enough info to back up ANY of the claims I've seen here. Get some honest dyno graphs and we can make our power decisions. BTW, the question was not an ethical question, it was an honest question about power. Don't make it any more than that. :cheers:
If you remove your cats because you are installing headers, you'll certainly see an increase because the headers flow more than stock manifolds anyway.
Cats added horsepower, well let's just put that into the proper perspective shall we. These are brand new, high performance cats, meant for such an application. A brand new stock cat would NOT give you the same results. Also I'd love to see the actual dyno graphs for these claims. Sure it might add 5 horespower at the peak, but what does it do for the rest of the power curve? Without looking at the dyno graph, it's useless info. Peak numbers are crap, think of averages, and lets use a lightbulb example. If you have a box of 5 lightbulbs, 4 of them will blow out in 1 hour, the other one lasts 1,000,000 hours. The AVERAGE for the box is still 200,000 hours. The same thing works for PEAK numbers. Peaks and averages are useless unless you know more info.
I'm not trying to call anybody a liar here, but I'm just gonna say that I don't have enough info to back up ANY of the claims I've seen here. Get some honest dyno graphs and we can make our power decisions. BTW, the question was not an ethical question, it was an honest question about power. Don't make it any more than that. :cheers:
02-02-2002, 07:06 PM
#10
Race Director
Re: How many horses do you get out of removing Catalytic Converter?? (Nathan Plemons)
I agree with what Nathan said there...without seeing the results for yourself, a test may be useless on paper.Btw I mentioned something about the 5Hp difference,let me clarify that..
with a high flow cat,it made 5HP less then no cat at all.So the gain was small enough to say its silly not to run a cat.I didnt mean to make it sound like the Hi flow cat gained HP.And it may have well been peak power at redline,where on the street its null.
Our cars dont spend all its time up there in the powerband much and its insane to do on the street eh?
:D
Every car is different too and at least most agree theres no real gain on a properly tuned and excellent running car by removing the cat unless it was ld and restricted and holding some power back.
:)
with a high flow cat,it made 5HP less then no cat at all.So the gain was small enough to say its silly not to run a cat.I didnt mean to make it sound like the Hi flow cat gained HP.And it may have well been peak power at redline,where on the street its null.
Our cars dont spend all its time up there in the powerband much and its insane to do on the street eh?
:D
Every car is different too and at least most agree theres no real gain on a properly tuned and excellent running car by removing the cat unless it was ld and restricted and holding some power back.
:)
02-02-2002, 07:23 PM
#12
Re: How many horses do you get out of removing Catalytic Converter?? (Bill's86Coupe)
I have actually seen where people claim to GAIN power by adding high flow cats. Probably a little torque due to the added backpressure. Nothing major though, I would like to see an extensive study.
I think what gets a lot of people is the cost. Why pay a whole lot of money to give up a little power. In my case I removed my stock system and installed Long Tube headers, got a custom X-pipe, and installed flowmaster mufflers. I picked up 23 hp and 32 pounds of torque. Now you will have a REAL hard time convincing me to spend an extra 300 to give up some of that power. For now I'm cool until emissions are mandatory in my area. I know it's rough on the environment, but at least mine is tuned properly. I see Jethro's pickup truck as a bigger threat to the environment. You know the ones I mean, that blow so much smoke you can't stand to be behind them. I'm causing a lot less pollution than them.
If it ever becomes mandatory, I'll put emissions equipment back on my car, until that point I'm gonna squeeze every bit of power I can out of it. I still have my manifolds, cats included, and AIR pump in a box, just in case :) Again I'll stress that I added headers, which makes it real costly to put cats back in place, thats why I don't have any. Punching out the stock cat is silly, it won't gain anything and CAN hurt you unless you do it right.
Just my $.02 on the subject.
I think what gets a lot of people is the cost. Why pay a whole lot of money to give up a little power. In my case I removed my stock system and installed Long Tube headers, got a custom X-pipe, and installed flowmaster mufflers. I picked up 23 hp and 32 pounds of torque. Now you will have a REAL hard time convincing me to spend an extra 300 to give up some of that power. For now I'm cool until emissions are mandatory in my area. I know it's rough on the environment, but at least mine is tuned properly. I see Jethro's pickup truck as a bigger threat to the environment. You know the ones I mean, that blow so much smoke you can't stand to be behind them. I'm causing a lot less pollution than them.
If it ever becomes mandatory, I'll put emissions equipment back on my car, until that point I'm gonna squeeze every bit of power I can out of it. I still have my manifolds, cats included, and AIR pump in a box, just in case :) Again I'll stress that I added headers, which makes it real costly to put cats back in place, thats why I don't have any. Punching out the stock cat is silly, it won't gain anything and CAN hurt you unless you do it right.
Just my $.02 on the subject.
02-02-2002, 11:11 PM
#13
Drifting
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Re: How many horses do you get out of removing Catalytic Converter?? (Nathan Plemons)
Well today I just found out that removing my cats, getting long tubes, and an H-pipe gave me 5/10 in the 1/4, so I'd say remove them and get some headers.
I did change the spark plugs too, and put in an MSD box, but I don't think that made that much difference. My car was idling very funny today too, so I don't know if when I installed everything, I didn't cause another problem. So who knows the 5/10 could have been more.
I did change the spark plugs too, and put in an MSD box, but I don't think that made that much difference. My car was idling very funny today too, so I don't know if when I installed everything, I didn't cause another problem. So who knows the 5/10 could have been more.
02-03-2002, 12:24 AM
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Re: How many horses do you get out of removing Catalytic Converter?? (BAdAzZV8)
NICE.
I am running a high-flow cat in my car, and it is overdue for emissions. maybe after I pass it next week, I'll try a gutted one. Im planing to go to the track this year a few times to meet some of you guys anyways..
I am running a high-flow cat in my car, and it is overdue for emissions. maybe after I pass it next week, I'll try a gutted one. Im planing to go to the track this year a few times to meet some of you guys anyways..
02-03-2002, 12:45 AM
#15
Safety Car
Re: How many horses do you get out of removing Catalytic Converter?? (MrNuke)
Interesting subject....I'm not sure on the power pick-up with a stock L98 motor, I've heard of a few picking up some nice gains on a stock motor, and I've had a few others report to me that the payout was little to nothing.
But, a few years back when my motor was still a 350, I was modified with aftermarket tube runners, ported plenum, Dart heads, LPE 74211, and headers, I conducted what I consider a very accurate before and after test with the single cat.
I took off my brand new shiny GM cat and installed a gutted cat and picked up literally 20 hp... broke every personal record I had including 60 ft my very 1st pass with the gutted cat.... I then put the very clean, not-clogged gm cat back in and I went slower by 2 tenths and 2 mph.
I think a point needs to be brought up that is very important as to if a cat impedes performance or not... and that is if the car is equiped with 1 or 2 main cats. I think a modified motor with 2 good flowing cats will pick-up very little hp by removing them, however, a modified motor running through a single cat, regardless of if it is a high flow unit or not, is really choking itself..... Thus in my mind, the ideal set-up is running two high flow bullet cats.... hard to fit up in the tunnel though, but I've heard of a few squeezing them in.
As another note, after a long discussion with Brad of Random Technologies a few years back, he gave me an honest # on what I would pick-up in power by going from a stock gm cat to a single Random cat.... the hp # was 6 hp.... which is pretty good, but a far cry from 20hp.
Food for thought.
Beach Bum
But, a few years back when my motor was still a 350, I was modified with aftermarket tube runners, ported plenum, Dart heads, LPE 74211, and headers, I conducted what I consider a very accurate before and after test with the single cat.
I took off my brand new shiny GM cat and installed a gutted cat and picked up literally 20 hp... broke every personal record I had including 60 ft my very 1st pass with the gutted cat.... I then put the very clean, not-clogged gm cat back in and I went slower by 2 tenths and 2 mph.
I think a point needs to be brought up that is very important as to if a cat impedes performance or not... and that is if the car is equiped with 1 or 2 main cats. I think a modified motor with 2 good flowing cats will pick-up very little hp by removing them, however, a modified motor running through a single cat, regardless of if it is a high flow unit or not, is really choking itself..... Thus in my mind, the ideal set-up is running two high flow bullet cats.... hard to fit up in the tunnel though, but I've heard of a few squeezing them in.
As another note, after a long discussion with Brad of Random Technologies a few years back, he gave me an honest # on what I would pick-up in power by going from a stock gm cat to a single Random cat.... the hp # was 6 hp.... which is pretty good, but a far cry from 20hp.
Food for thought.
Beach Bum
