Cats or no cats?
Thread Starter
Heel & Toe
Joined: Jan 2015
Posts: 23
Likes: 0
Cats or no cats?
So Im ordering a new setup and was wondering how much difference there is between cats and no cats. I'm going to get the "highflow cats" if I do. Is there a smell when it's uncatted or does it drone hard. Let me know opinions!
Melting Slicks
Joined: Nov 2013
Posts: 2,049
Likes: 316
From: USA
Personal preference is what it comes down to really. I have Kooks headers and have ran it with both their catted and catless X-pipe. Performance wise it's been proven time and time again it's negligible. Sound wise catted is a little bit more muffled... a little more 'smooth' sounding. Catless is a bit more of a raw sound (if that makes sense) at wide open throttle.
For me, I don't really *dislike* the catless smell, but it would get old in a daily driven car. My car is my weekend fun car so I don't mind the catless smell for this application.
For me, I don't really *dislike* the catless smell, but it would get old in a daily driven car. My car is my weekend fun car so I don't mind the catless smell for this application.
Burning Brakes
Joined: Sep 2004
Posts: 1,003
Likes: 1
From: Richmond VA
I would go with the cats. The power loss is negligible. Without cats does sound better without question.
I don't have cats and if done again (and I just may soon) i would add them.
The smell isn't bad, but it is noticable and I don't care for it.
I don't have cats and if done again (and I just may soon) i would add them.
The smell isn't bad, but it is noticable and I don't care for it.
Burning Brakes
Joined: Oct 2013
Posts: 859
Likes: 1
I run no cats. You get that "old muscle car smell." It's not for everybody, and sometimes if you ride around with the windows down your clothes will smell like you just mowed. I don't mind. Now, there is minimal hp difference between running cats and no cats, so it's really personal preference
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
I ran an off road X system for a year or so, and added HF cats. They're a metal matrix, so they don't impede flow much, if any, and they reduce the smell, but don't eliminate it. Your cam overlap will have more to do with the smell than the cats. You can also tune the injector timing to reduce smell.
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Drifting
Joined: Mar 2000
Posts: 1,956
Likes: 135
From: Maryland
I'm catless and don't mind the smell. Its no different than the cars I drove when growing up. But then again, I like the smell of my 2-stroke motocross bike.
If you have never smelled an uncorked rotary, you don't know what bad exhaust is. My roots supercharged Rx7 would drop you to your knees as if you were maced.
If you have never smelled an uncorked rotary, you don't know what bad exhaust is. My roots supercharged Rx7 would drop you to your knees as if you were maced.
Advanced
Joined: Mar 2015
Posts: 81
Likes: 0
I'm catless and don't mind the smell. Its no different than the cars I drove when growing up. But then again, I like the smell of my 2-stroke motocross bike.
If you have never smelled an uncorked rotary, you don't know what bad exhaust is. My roots supercharged Rx7 would drop you to your knees as if you were maced.
If you have never smelled an uncorked rotary, you don't know what bad exhaust is. My roots supercharged Rx7 would drop you to your knees as if you were maced.
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
I'm about to put my stock cats back on after having them removed about a year ago. I'm tired of the smell and theres barely any hp increase. Only real gain of going catless would be weight reduction but thats not much.
Acct Suspended APR 2026 by request
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2020 Corvette of the Year Finalist (performance mods)
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I don't run cats on mine, I happen to like the smell and extra noise... if you are or plan on doing any form of forced induction I would not run cats... forced induction cars tend to run a little on the rich side when compared to other cars and will likely burn the cats out and could cost you a motor if you aren't lucky
Le Mans Master
Joined: Sep 2014
Posts: 5,278
Likes: 539
From: Kelowna BC
Yep, my Magnaflow cats are very light... much lighter than the factory units it seems (didn't weigh either, just handling).
Advanced
Joined: Mar 2015
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