Cat Delete w/ NPP - How does it sound???
Thread Starter
Racer
Joined: Sep 2012
Posts: 311
Likes: 20
Cat Delete w/ NPP - How does it sound???
Im considering gutting an extra set oem cats for my 08 ls3 vette. Im sure it will sound great but is the smell that bad?? I know about the codes and a reputable tuner is only 30 minutes from me. Just want to know about smell and sound 
Burning Brakes
Joined: Mar 2012
Posts: 861
Likes: 27
From: Rogers AR
I put American Racing 1 3/4 headers with catless x-pipe on my '10 GS a couple of weeks ago. The smell is significant I would say. In the garage getting ready to back out the odor is strong. Idling in the open it is smelly as well. I often recirculate the air and that helps. But it sounds awesome!
Burning Brakes
Joined: Mar 2012
Posts: 861
Likes: 27
From: Rogers AR
I can try to get some clips this next week while I'm off work.
Sound is worth it over smell. Hitting the recirculation button fixes the smell for me. For the unfortunate drivers behind or around me though...
When it hits 4k rpms the sound is awesome. Below 4k it's almost the same as stock carted headers.
Sound is worth it over smell. Hitting the recirculation button fixes the smell for me. For the unfortunate drivers behind or around me though...
When it hits 4k rpms the sound is awesome. Below 4k it's almost the same as stock carted headers.
Cruising
Joined: Jul 2012
Posts: 10
Likes: 0
From: Cedar Rapids Iowa
I just got this done on my 2008 Corvette with the LS3 motor. I'm extremely happy with the sound and it really doesn't smell very much. The smell isn't bad either, it just smells more like a racecar fuel type of smell. The sound is a little louder and has a more cammy mechanical type of sound to it. It definitely was the sound that I wanted in the car, separates it from the stock exhaust a little but not too much. (The stock exhaust was a little too quiet for me). Also with the mild to wild switch.. the mild makes it just as quiet as how the mild was with cats still present. It is very quiet when made mild. When wild its just has a little more rumble. Also you will notice a rumble when you let off the gas when cruising. This was there before but was muffled by the cats, now you can hear it a little better. I had my car tuned professionally to limit backfire and make sure that rumble noise wasn't overbearing at highway speeds. After the upgraded ram air intake and catless exhaust and a tune, I can definitely feel the performance upgrade as well. I'll be happy to answer any questions you may have.
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Race Director
Joined: Oct 2005
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From: Saint Albans, WV
Racer
Joined: Dec 2012
Posts: 254
Likes: 1
From: Midland TX
I have that setup on mine and absolutely love it. The NPP was a necessity for me when purchasing because of the M2W switch. You do get a little bit of a smell at the rear of the car more so than when it was stock but I hardly notice it as I am used to it. I absolutely love the sound and wouldn't have it any other way. I wanted to get the Corsa extreme but wanted to have the dual mode option for roadtrips. The sound is fantastic and well worth the smell in my opinion!
heres a video for you. It isn't exactly what you're looking for as it is a dyno video and not just a rev but you can get an idea. definitely sounds MUCH better in person though.
heres a video for you. It isn't exactly what you're looking for as it is a dyno video and not just a rev but you can get an idea. definitely sounds MUCH better in person though.
Last edited by 1quickTXVette; Jun 2, 2014 at 03:37 PM.
Pro
Joined: Jul 2013
Posts: 509
Likes: 62
on an otherwise stock car removing or gutting the cats will probably have little to no difference in sound or performance, but I'm sure you'll get a good bit of smell. go with longtubes and high-flow cats if you want a noticeably different sound. you'll still get a little smell!!
Racer
Joined: Dec 2012
Posts: 254
Likes: 1
From: Midland TX
I agree, I would do long tube headers. I misread your post and thought you had headers currently but it was another post. If you want to add some noise and performance do long tubes with no cats and the npp that is the exhaust setup I run