View Poll Results: High Flow Cats - Necessary?
Necessary
52
67.53%
Not Necessary
25
32.47%
Voters: 77. You may not vote on this poll
POLL - High Flow Cats
Thread Starter
Team Owner
Joined: Sep 2007
Posts: 21,915
Likes: 61
From: Miami Beach FL
After reading some of the replies after mine, maybe I'd change my opinion. If not having cats is going to make you smell gas inside the car and make you smell like gas after driving, then THAT would be enough to make me stay with the cats on my car.
I am glad I heard this info. I never heard this before......
Thanks
I am glad I heard this info. I never heard this before......
Thanks
There's some great info being passed along here, thanks again to everyone for their imput. I believe this will be a great resource thread for those researching the subject. 
Burning Brakes
Joined: Jan 2004
Posts: 896
Likes: 1
From: Overland Park KS
For about 2 months, I ran without cats on a modified '96 Trans Am with long tubes. Even tuned, the smell was HORRIBLE and the sound was very "raspy". 
I put RT high-flows on afterwards and it removed the harsh exhaust notes and removed the stink issue entirely. The car sounded killer and only dyno'd ~6rwhp less. I will never again go without cats on a car unless it's track-only.
IMO, a raspy, stinky exhaust does not fit the image of a late model street-driven Corvette. Track cars are a different story. My C5 runs LG Pro LTs with Random Tech HF cats and a set of quad Borla Stingers. This setup is music to my ears and receives TONS of compliments!
I say go with the cats!
I put RT high-flows on afterwards and it removed the harsh exhaust notes and removed the stink issue entirely. The car sounded killer and only dyno'd ~6rwhp less. I will never again go without cats on a car unless it's track-only.IMO, a raspy, stinky exhaust does not fit the image of a late model street-driven Corvette. Track cars are a different story. My C5 runs LG Pro LTs with Random Tech HF cats and a set of quad Borla Stingers. This setup is music to my ears and receives TONS of compliments!
I say go with the cats!
Administrator
Joined: Jun 2007
Posts: 66,409
Likes: 2,061
From: Bel Air (by way of Fort Worth, TX) Maryland
St. Jude Donor '12 thru '21
For about 2 months, I ran without cats on a modified '96 Trans Am with long tubes. Even tuned, the smell was HORRIBLE and the sound was very "raspy". I put RT high-flows on afterwards and it removed the harsh exhaust notes and removed the stink issue entirely. The car sounded killer and only dyno'd ~6rwhp less. I will never again go without cats on a car unless it's track-only.
IMO, a raspy, stinky exhaust does not fit the image of a late model street-driven Corvette. Track cars are a different story. My C5 runs LG Pro LTs with Random Tech HF cats and a set of quad Borla Stingers. This setup is music to my ears and receives TONS of compliments!
I say go with the cats!
I put RT high-flows on afterwards and it removed the harsh exhaust notes and removed the stink issue entirely. The car sounded killer and only dyno'd ~6rwhp less. I will never again go without cats on a car unless it's track-only.IMO, a raspy, stinky exhaust does not fit the image of a late model street-driven Corvette. Track cars are a different story. My C5 runs LG Pro LTs with Random Tech HF cats and a set of quad Borla Stingers. This setup is music to my ears and receives TONS of compliments!
I say go with the cats!
Be careful. I have posted this as my position in the past and got flamed for it
At any rate, the OP lives in a county with emissions testing, so my advice to him would be to at least research testing stations near him and verify what his "limitations" are before making his decision
Melting Slicks
Joined: Feb 2006
Posts: 3,191
Likes: 43
From: Scottsdale Az
Be careful. I have posted this as my position in the past and got flamed for it
At any rate, the OP lives in a county with emissions testing, so my advice to him would be to at least research testing stations near him and verify what his "limitations" are before making his decision
At any rate, the OP lives in a county with emissions testing, so my advice to him would be to at least research testing stations near him and verify what his "limitations" are before making his decision
I say run no cats. I haven't run them for 3 years and no issues.
Administrator
Joined: Jun 2007
Posts: 66,409
Likes: 2,061
From: Bel Air (by way of Fort Worth, TX) Maryland
St. Jude Donor '12 thru '21
I personally wouldn't run my car without them (the gas smell and the associated hassles that come with taking them off) but that is just me
Race Director
Joined: Jun 2004
Posts: 19,459
Likes: 48
From: Schaumburg IL
CI 7-8-9-11 Veteran
St. Jude Donor '06-'10, '13
After reading some of the replies after mine, maybe I'd change my opinion. If not having cats is going to make you smell gas inside the car and make you smell like gas after driving, then THAT would be enough to make me stay with the cats on my car.
I am glad I heard this info. I never heard this before......
Thanks
I am glad I heard this info. I never heard this before......
Thanks
I've ridden in, and driven behind a good number of C5;'s without cats and most (not all) stink! Even wtih a good tune. My car even with hi-flow cats smells fairly strong upon start up until the hi-flow cats warm up (which obviously takes longer than the stockers).You dont gain all that much HP running no-cats....maybe in the olden days of the great muscle cars when technology was not as great and things were not computer tuned.....but anything under a 20 HP gain is not worth the sacrifice IMO.
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Thread Starter
Team Owner
Joined: Sep 2007
Posts: 21,915
Likes: 61
From: Miami Beach FL
There have been very good points made by all on this matter. I feel that it will be in my best interest to install the cats with the LT's. Inspection here is visual and having never thought of the odor aspect I believe this is a no-brainer.
Administrator
Joined: Jun 2007
Posts: 66,409
Likes: 2,061
From: Bel Air (by way of Fort Worth, TX) Maryland
St. Jude Donor '12 thru '21
I respect the position of those that don't want to run cats. IMHO
it is not the idea thing to do, but I understand the motivation behind it. There are a couple of guys in my unit that have Vettes and don't run cats (high-flow or OEM) and get away with it because they don't do emissions testing in my part of Texas.
Running catless is not my bag, and I really don't think it gains you much unless you are building and all-out, dedicated track car, but if you can get away with it, who am I to criticize......
it is not the idea thing to do, but I understand the motivation behind it. There are a couple of guys in my unit that have Vettes and don't run cats (high-flow or OEM) and get away with it because they don't do emissions testing in my part of Texas.
Running catless is not my bag, and I really don't think it gains you much unless you are building and all-out, dedicated track car, but if you can get away with it, who am I to criticize......
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
Do you have a list of tracks that are isolated from the same atmosphere the rest of us live under?
If no, what's the difference?
I mean, You say I need to trailer my catless car 6 miles to the local track, but you have no problem if I run it WOT for 50 miles there? Does that make any sense at all?
It sounds like you're trying to be politically correct, but have no idea why.
If no, what's the difference?
I mean, You say I need to trailer my catless car 6 miles to the local track, but you have no problem if I run it WOT for 50 miles there? Does that make any sense at all?
It sounds like you're trying to be politically correct, but have no idea why.
Administrator
Joined: Jun 2007
Posts: 66,409
Likes: 2,061
From: Bel Air (by way of Fort Worth, TX) Maryland
St. Jude Donor '12 thru '21
There is a BIG *** difference and yes I know why. A race car runs far a short time,,especially if it's a drag car.You are running a street carone hellava lot longer,doesn't take a rocket scientist to figure out you'r poluting a lot more driving every day for hours and miles at a time vs a car that runs a little once every once in a while.With modern technology there is no reason to go catless.With a properly designed and tuned system there is no gain worth talking about.
Melting Slicks
Joined: Feb 2007
Posts: 3,188
Likes: 10
From: New Smyrna Beach Florida
Why not go with hi-flow cats and be done with it. In many cases, guys with no cats get tired of the sound and especially the stink, plus the difference in hp is very small. Very hard to justify no cats on a street car.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
There is a BIG *** difference and yes I know why. A race car runs far a short time,,especially if it's a drag car.You are running a street carone hellava lot longer,doesn't take a rocket scientist to figure out you'r poluting a lot more driving every day for hours and miles at a time vs a car that runs a little once every once in a while.With modern technology there is no reason to go catless.With a properly designed and tuned system there is no gain worth talking about.
Please don't tell me about my gross polluting car that gets daily driven for hours a day...blah blah blah.
My odometer reads exactly 104 miles more than it did last October.
Of those 104 miles, would you care to guess how many were on track, and how many off? And can you then explain which of those miles polluted the environment more? That was all I asked to begin with.
Thanks
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
Please don't think that the use of hi flow cats is being "responsible" as mentioned above.
I was not only able to see straight through a brand new Random Technologies Hi-Flow cat but I could make out exactly what I was looking at on the other end. They are about as useful as a hood seal on your Corvette.
I was not only able to see straight through a brand new Random Technologies Hi-Flow cat but I could make out exactly what I was looking at on the other end. They are about as useful as a hood seal on your Corvette.
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
So you can't answer the question as it was asked.? I didn't even use any big words or anything...
Please don't tell me about my gross polluting car that gets daily driven for hours a day...blah blah blah.
My odometer reads exactly 104 miles more than it did last October.
Of those 104 miles, would you care to guess how many were on track, and how many off? And can you then explain which of those miles polluted the environment more? That was all I asked to begin with.
Thanks
Please don't tell me about my gross polluting car that gets daily driven for hours a day...blah blah blah.
My odometer reads exactly 104 miles more than it did last October.
Of those 104 miles, would you care to guess how many were on track, and how many off? And can you then explain which of those miles polluted the environment more? That was all I asked to begin with.
Thanks
Burning Brakes
Joined: Mar 2008
Posts: 756
Likes: 1
From: Raleigh NC
So you can't answer the question as it was asked.? I didn't even use any big words or anything...
Please don't tell me about my gross polluting car that gets daily driven for hours a day...blah blah blah.
My odometer reads exactly 104 miles more than it did last October.
Of those 104 miles, would you care to guess how many were on track, and how many off? And can you then explain which of those miles polluted the environment more? That was all I asked to begin with.
Thanks
Please don't tell me about my gross polluting car that gets daily driven for hours a day...blah blah blah.
My odometer reads exactly 104 miles more than it did last October.
Of those 104 miles, would you care to guess how many were on track, and how many off? And can you then explain which of those miles polluted the environment more? That was all I asked to begin with.
Thanks
Even if we were talking about a track car, it's not going to be driven anywhere near as much as a street car, and WOULDN'T be as bad catless as your average daily driven street car would be catless.
As far as arguing about 104 miles catless or catted, nobody cares. No big words there, either.
Racer
Joined: Nov 2005
Posts: 457
Likes: 0
From: Rockville MD
I currently run no cats... and yes it stinks.... I dont ever smell of fuel but you can certainly smell it when driving....
my car is registered in a county where there is no testing.. however I would just get the high flows...
If its true that after the tune the car will still stink. then I will probably get high flows as well...
my car is registered in a county where there is no testing.. however I would just get the high flows...
If its true that after the tune the car will still stink. then I will probably get high flows as well...
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
I currently run no cats... and yes it stinks.... I dont ever smell of fuel but you can certainly smell it when driving....
my car is registered in a county where there is no testing.. however I would just get the high flows...
If its true that after the tune the car will still stink. then I will probably get high flows as well...
my car is registered in a county where there is no testing.. however I would just get the high flows...
If its true that after the tune the car will still stink. then I will probably get high flows as well...