Cats No Cats
Le Mans Master
Joined: Jun 2004
Posts: 6,752
Likes: 3
From: Bethlehem PA
Very little difference maybe 5-7 ponies at most depending on your mods.
The sound is only slightly louder with factory cat back and more so with aftermarket exhaust.
I started with off road x pipe and Borla Stingers (2 tip) and, after installing long tube headers, it got brutal loud. I traded them for Z06 Ti's and was very happy with the decibel drop, yet I still had the nice rumble when I put my foot in it.
Finally put hi flow cats on last week.
I don't think it's worth the minimal gain to deal with the headaches of not having cats. Smell, noise, inspection.
For a track only car, I'd do without the cats in a heartbeat, but I'm assuming this isn't your purpose.
Scott
The sound is only slightly louder with factory cat back and more so with aftermarket exhaust.
I started with off road x pipe and Borla Stingers (2 tip) and, after installing long tube headers, it got brutal loud. I traded them for Z06 Ti's and was very happy with the decibel drop, yet I still had the nice rumble when I put my foot in it.
Finally put hi flow cats on last week.
I don't think it's worth the minimal gain to deal with the headaches of not having cats. Smell, noise, inspection.
For a track only car, I'd do without the cats in a heartbeat, but I'm assuming this isn't your purpose.
Scott
Safety Car
Joined: Jun 2004
Posts: 4,353
Likes: 22
From: Bella Vista Ca
I've seen a post from before and after Random Cats with headers and cat backs... It was only about 2 Hp difference. I ran my car without cats for about a week. The cars smelled like an old broke-down truck every time a I stopped at a light. Run the cats. 
Safety Car
Joined: Dec 2000
Posts: 4,798
Likes: 2
From: Norman Oklahoma
Cruise-In III Veteran
St. Jude Contributor
I like the sound better but I hate my clothes smelling like fumes when I get out of the car.
If I didn't use my car for regular driving I would run catless.
My car dynoed the same HP but lost a pinch of torque with cats vs. no cats.
If I didn't use my car for regular driving I would run catless.
My car dynoed the same HP but lost a pinch of torque with cats vs. no cats.
Pro
Joined: Jun 2004
Posts: 543
Likes: 1
From: Detroit MI
Im running stright pipe, Lg headers no cats and slp loudmouth. I love the sound, like a race car. why spend 400$ the car is not going to pass anyways. just to rid the smell it is not even that noticable.
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Pro
Joined: Oct 2004
Posts: 547
Likes: 0
From: Ft. Myers FL
Im in FL...so AC and Recirc=no bad smell...
Cats will always take away midrange and top end power...they are just a natural restriction...more mods you have..the more it takes away... and they get clogged
Cats will always take away midrange and top end power...they are just a natural restriction...more mods you have..the more it takes away... and they get clogged
Instructor
Joined: Apr 2003
Posts: 202
Likes: 0
From: brownstown mi
This was the 3rd thing i did to my car.I started with air box and wanted
the sound to be a bit louder. I bought borla cat-bac (not the stinger).
It still was't loud enough.So i heard that off-road x-pipe increase sound level.
After install I still wanted it louder,so it made little increase.The sound
is better with x-pipe (smoother)though.Now for the point of this story.
I could have cried after a couple of cruises .The smell made me almost
sick. I forgot what driving in parents cars used to be like.My car had
new car smell, now exhaust smell.You do get use to it i guess.
If any power increase i could not feel it and my 1/4 mile did not change.Driving comfort did decrease . My next modd will be headers with hi-flo catts.
Greg
the sound to be a bit louder. I bought borla cat-bac (not the stinger).
It still was't loud enough.So i heard that off-road x-pipe increase sound level.
After install I still wanted it louder,so it made little increase.The sound
is better with x-pipe (smoother)though.Now for the point of this story.
I could have cried after a couple of cruises .The smell made me almost
sick. I forgot what driving in parents cars used to be like.My car had
new car smell, now exhaust smell.You do get use to it i guess.
If any power increase i could not feel it and my 1/4 mile did not change.Driving comfort did decrease . My next modd will be headers with hi-flo catts.
Greg
Le Mans Master
Joined: Aug 2000
Posts: 5,294
Likes: 2
From: Suffolk, Long Island NY
Depending on the rest of your exhaust and motor setup, removing your cats can make the car much louder. The car will smell too, how much depends on your tune, cam, etc..
Redgar recently posted that going from high flow cats to catless on his H&C A4 dropped a tenth off his 1/4 times.
Redgar recently posted that going from high flow cats to catless on his H&C A4 dropped a tenth off his 1/4 times.
Safety Car
Joined: Apr 2003
Posts: 4,251
Likes: 7
From: Woodbridge Ontario
Originally Posted by Vette#2
No smell from mine, must be the tune
I don't smell anything, but several people did comment on the smell, and my wife refuses to come in the Vette now.....
Team Owner
Joined: Feb 2000
Posts: 32,545
Likes: 2
From: Lithia FL
Cruise-In II & IV Veteran
CI VI Drag Champ!
As Face said, we just did the swap at the track and got a tenth which is about 10 hp
See the post
http://forums.corvetteforum.com/show...1&forum_id=108
See the post
http://forums.corvetteforum.com/show...1&forum_id=108
Melting Slicks
Joined: Jul 2004
Posts: 2,226
Likes: 65
From: West hills California
Originally Posted by REDGAR
As Face said, we just did the swap at the track and got a tenth which is about 10 hp
See the post
http://forums.corvetteforum.com/show...1&forum_id=108
See the post
http://forums.corvetteforum.com/show...1&forum_id=108
Team Owner
Joined: Feb 2000
Posts: 32,545
Likes: 2
From: Lithia FL
Cruise-In II & IV Veteran
CI VI Drag Champ!
Originally Posted by c5wolf
dont get me wrong as I am into sick performance but it seems like a bad way to make power as we have kids and the cats are so much better for the environment and with the level of perf avail with our vets it seems a shame to get a minimal increase on a street car and be illegal, besides I got a 2500 dollar ticket and had to go to a referee station when a chp got under my car and nailed me for no cats
and it is much less emissions than the 18 wheelers and buses traveling on the road
Burning Brakes
Joined: Jun 2003
Posts: 1,116
Likes: 64
From: San Francisco California
440rwhp thru Maganflow 3" hi flow cats (Long tube headers, cats, Xpipe, dual 3" all the way back)
I don't see the point of not running them here in CA. Fine to ditch them is $2500+.
I don't see the point of not running them here in CA. Fine to ditch them is $2500+.
Burning Brakes
Joined: Oct 2004
Posts: 769
Likes: 0
From: simpson town Mo
Kooks and catless.NO smell.And not im use to it no smell but NO smell at all. Never had a comment on the smell and wife loves it. But ive had plenty of compliments on the sound.Bullets and kooks. MMM MMM MMM MMM good.