Need real answer: Does removing the cat's increase power?
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Re: Need real answer: Does removing the cat's increase power? (Mike Mercury)
I know of a few people (non vettes) who pass the sniffer with no cats. That is, the emissions from the tailpipe are still within the llimits for that car. (here at least). I find it difficult to believe those cars pollute the equivalent of 100 cars each. :rolleyes:
Whats even better, is most places seem to be migrating to testing OBDII cars by simply tapping into the computer. If it's not throwing codes, it's good to go. Drop the cats and put 02 sims on, no problem. The people with visual inspection would likely have a problem though.
I have the 02 sims on my car already, with the cats. I could easily drop the cats if I wanted, install the ORP's, and still probably pass emissions with flying colors, or just swap the cats back in before testing. Don't really see a need to though, that minor increase in power isn't worth the hassle or federal law infraction to me. I don't really need nor want it any louder either. :D
:cheers:
Whats even better, is most places seem to be migrating to testing OBDII cars by simply tapping into the computer. If it's not throwing codes, it's good to go. Drop the cats and put 02 sims on, no problem. The people with visual inspection would likely have a problem though.
I have the 02 sims on my car already, with the cats. I could easily drop the cats if I wanted, install the ORP's, and still probably pass emissions with flying colors, or just swap the cats back in before testing. Don't really see a need to though, that minor increase in power isn't worth the hassle or federal law infraction to me. I don't really need nor want it any louder either. :D
:cheers:
Le Mans Master
Joined: Aug 2001
Posts: 6,071
Likes: 297
From: Savannah GA
Cruise-In IV Veteran
Re: Need real answer: Does removing the cat's increase power? (Aquaman)
I do not recommend anyone pulling their cats, especially on stock cubes n/a, but I love how everyone says, "It only gave me 5rwhp...", and never mention the fact that the car was not tuned to take advantage of removed cats.
Yes, the sound is awesome and I am running B&B Triflow Rt. 66 mufflers! Of course cubes and a good cam really contribute to that. :crazy:
[Modified by C5-VERT, 12:51 PM 12/12/2002]
Yes, the sound is awesome and I am running B&B Triflow Rt. 66 mufflers! Of course cubes and a good cam really contribute to that. :crazy:
[Modified by C5-VERT, 12:51 PM 12/12/2002]
Drifting
Joined: Mar 2000
Posts: 1,956
Likes: 135
From: Maryland
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
AMEN BROTHER!!
I certainly didn't vote for the change that reduces emissions requirements for the nations dirtiest power plants!
I certainly didn't vote for the change that reduces emissions requirements for the nations dirtiest power plants!
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.
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.
Burning Brakes
Joined: Jun 2002
Posts: 1,037
Likes: 31
From: Richmond Texas
Re: Need real answer: Does removing the cat's increase power? (larrysb)
With all due respect Tom, you are FOS.
Even diesels have cats today.
Even diesels have cats today.
☠☣☢ Semper Ebrius ☢☣☠
Joined: Jun 2001
Posts: 83,301
Likes: 4
From: Virginia
Cruise-In IV-V-VI-VII Veteran
St. Jude's Donor '06
Re: Need real answer: Does removing the cat's increase power? (BigBlue)
Unless you increase your displacement, removal of the cats will not help you significantly.
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? (KingTut)
Everytime you post you use up large portions of the page quoting other people and directly confronting their opinions.
I am not sure of any of your actual positions on things,
only that you find excessive faults in others opinions.
1st person: Here's what I think...
2nd person: Me too!
3rd person: I agree too!
ad nauseum...
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)
Tom, I have to stick up for you...your right on, although I don't encourage anyone to remove their cats...it should be their choice.
And on the diesels, they put out visible smoke, but these are mostly less harmful large particles that fall to the ground more quickly, not suspending in the air. And yes, the exhaust temp is not high enough to heat a traditional cat hot enough to be effective. I drive a Excursion diesel for the race car tow vehicle. :cheers:
And on the diesels, they put out visible smoke, but these are mostly less harmful large particles that fall to the ground more quickly, not suspending in the air. And yes, the exhaust temp is not high enough to heat a traditional cat hot enough to be effective. I drive a Excursion diesel for the race car tow vehicle. :cheers:
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Drifting
Joined: Aug 2002
Posts: 1,317
Likes: 0
From: Lancaster CA
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
Get a bigger monitor then. I use large portions of the page because I actually RESEARCH the stuff I am talking about and quote sources rather than just spouting off my unsupported opinions.
Just my way of saying I appreciate the extra effort to support your point of view.
:cheers:
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
Re: Need real answer: Does removing the cat's increase power? (QUIKAG)
You would think you would get more hp. Haven't seen it with observing over a dozen dyno tests. Some loose some gain a couple all within the dyno error range so don't waste your money and time on it. For those you see 10, your breathing the fums guys.
Melting Slicks
Joined: May 2000
Posts: 2,974
Likes: 5
From: CenTex Texas
Re: Need real answer: Does removing the cat's increase power? (QUIKAG)
For peak it did nothing for me, however at 3500 rpms i lost about 5 lbs TQ. I can even post a comparison dyno graph if you like....JLMK.
Drifting
Joined: Jun 2000
Posts: 1,338
Likes: 0
From: Fontana CA
Re: Need real answer: Does removing the cat's increase power? (UtahVince)
I witnessed one forum member gain 6rwhp by removing the cats and adding O2 sims. His car had long tubes, cold air, maf translator, maf ends, and maybe a few more bolt-on type mods, but no head work, cam change or inclreased displacement.
Instructor
Joined: Sep 2002
Posts: 137
Likes: 0
From: Spring Grove Il
Re: Need real answer: Does removing the cat's increase power? (UtahVince)
Keep it up Tom, I agree with you most people don't research but just reply what someone else may have heard. You know, I haven't seen any of the big tuners who post on every other issue jumping in here with they're actuall dyno results to help justify the HP gains. 
Thread Starter
Le Mans Master
Joined: May 2000
Posts: 6,032
Likes: 124
From: Dallas TX
Re: Need real answer: Does removing the cat's increase power? (KerryH)
Thanks for all the info. Sorry to see my question go so far off topic. :D
KingTut, You're going into battle unarmed against Tom. Good luck!! :thumbs:
KingTut, You're going into battle unarmed against Tom. Good luck!! :thumbs:
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Re: Need real answer: Does removing the cat's increase power? (KerryH)
I use large portions of the page because I actually RESEARCH the stuff I am talking about
I'll trade my 2002 Z06 in for a 1967 Vette that pollutes a hundred times as much ...?
.
[Modified by Mike Mercury, 6:33 PM 12/12/2002]
Race Director
Joined: Aug 2002
Posts: 16,723
Likes: 1
From: Redacted
Re: Need real answer: Does removing the cat's increase power? (BigBlue)
Wrong.
We've owned two brand diesel cars in the last two years and they both are equiped with catalysts.
Says so right on the EPA sticker. I looked in the cat for one myself. It is indeed a catalyst matrix, just like a gasser.
Diesels are exempt from testing in many states, but they are NOT emmissions exempt. In many states opacity tests of the exhausts are required. The only reason they are not subject to rigorous testing in California is there are so few passenger cars equipped with diesels and the equipment required to test them is substantially different than that required for gasoline engines. Beginning in MY 2004, diesels will be coming under the same rules as gasoline vehicles as far as pollution goes.
Diesel produce far greater amounts of NOx and particulate matter. Particulate matter includes visible smoke particles. However PM is mostly composed of particles which are not visible and diesel do produce more of those than gasoline engines do.
We've owned two brand diesel cars in the last two years and they both are equiped with catalysts.
Says so right on the EPA sticker. I looked in the cat for one myself. It is indeed a catalyst matrix, just like a gasser.
Diesels are exempt from testing in many states, but they are NOT emmissions exempt. In many states opacity tests of the exhausts are required. The only reason they are not subject to rigorous testing in California is there are so few passenger cars equipped with diesels and the equipment required to test them is substantially different than that required for gasoline engines. Beginning in MY 2004, diesels will be coming under the same rules as gasoline vehicles as far as pollution goes.
Diesel produce far greater amounts of NOx and particulate matter. Particulate matter includes visible smoke particles. However PM is mostly composed of particles which are not visible and diesel do produce more of those than gasoline engines do.
With all due respect Tom, you are FOS.
Even diesels have cats today.
You are wrong my friend. Diesels do not come with cats. They come with something called a resonator. It is a 30% cat. A diesel doesn't really get hot enough to activate them. Diesels are also emissions exempt. I have straight pipe on mine and just got it inspected without any troubles. A diesel actually puts out less harmful particles than a gasser. A semi puts out as much harmful pollution (the stuff you can't see) as a minivan. It puts out more particulates (the black smoke). That's off boost though. You tip into boost and that exhaust cleans up real quick. My smokes like a freight train off the line but by 20mph, I'm half spool (15psi) and my exhaust is crystal clear. Just thought I would let you know.
Even diesels have cats today.
You are wrong my friend. Diesels do not come with cats. They come with something called a resonator. It is a 30% cat. A diesel doesn't really get hot enough to activate them. Diesels are also emissions exempt. I have straight pipe on mine and just got it inspected without any troubles. A diesel actually puts out less harmful particles than a gasser. A semi puts out as much harmful pollution (the stuff you can't see) as a minivan. It puts out more particulates (the black smoke). That's off boost though. You tip into boost and that exhaust cleans up real quick. My smokes like a freight train off the line but by 20mph, I'm half spool (15psi) and my exhaust is crystal clear. Just thought I would let you know.
Race Director
Joined: Aug 2002
Posts: 16,723
Likes: 1
From: Redacted
Re: Need real answer: Does removing the cat's increase power? (Tom Steele)
Get a bigger monitor then. I use large portions of the page because I actually RESEARCH the stuff I am talking about and quote sources rather than just spouting off my unsupported opinions. I know its a novel idea, and perhaps confusing to those who are used to the simplified version of things - but it is actually the correct way to debate an issue.
You are quite incorrect about NOx and diesels.
Diesel engines produce FAR greater quanties of NOx due to the over-abundance of oxygen available in the combustion chamber and the high peak temperature and pressure due to the higher compression ratios.
Compare the rolling dyno smog tests of a car with and without catalysts. The emmissions of unburned HC are 100 times greater without. I've seen it with my own eyes.
WTF do you think the "smell" is that people are talking about after pulling the cats?
It's unburned HC!!!
Geez, we've come so far in reducing pollution AND getting performance, WHY screw it up?
1. It's illegal in every state of the union.
2. It really does create a serious amount of pollution.
3. It doesn't gain any material improvement in performance.
Leave the damn things in place, unless you wish to go back to the truly horrendous era of 1973-like smog motor performance. Be thankful we have low-pollution and performance in this day and age!
While *TRUCKS* including SUV's fall under different rules, Corvettes are *CARS* and they fall under *CAR* rules which are the same for everybody, hot-rod freak or not.
Burning Brakes
Joined: Apr 2002
Posts: 1,081
Likes: 0
From: Mississauga ONTARIO
Re: Need real answer: Does removing the cat's increase power? (KingTut)
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 sometimes get too lazy to read Tom's posts.... ok, actually all of the time.... but the last time i checked, this was a Public Forum, and Tom is free to write what he chooses. Let the moderators worry about net etiquette.
sometimes you need to quote someone, because the point gets lost as the posts accumulate in the thread. if you dont like it, go to the next post, simple. gotta love how people try to tell others how to behave on forums...
im glad my mouse has that roller feature.....
im still laughing ....this place is toooo funny sometimes.