[blkcamarossredline]

I am looking to buy either an MBRP Race Cat Back or Axle Back and I have several questions. My first question is whether or not I would be leaving any power on the table by going with the axle back over the cat back. I know that power gains would be minimal with both systems but I would also not like to leave any power on the table by going with the axle back rather than the cat back. My second question is if the race cat back is any louder than the axle back. The videos on the internet make them seem about the same as far as sound goes but I haven't been able to compare them in person. My third and final question is if either or both of these systems would be significantly louder than the stock NPP muffler. People on here say that the in track mode the NPP is pretty much a straight pipe but then there are other people that claim that axle backs and cat backs such as these are much louder than the NPP. I would also like to note that my only mods are a Rotofab cold air intake and a WeaponX Motorsports ported throttle body. Any advice will be greatly appreciated.

[Abubaca]

Welcome! Where in NC are you???


Any exhaust mod, without headers, is not going to give you any real performance gain that you can feel. An axleback/catback is going to be pretty much for sound/volume, and for building for the future.
I went with the AWE "touring" axleback, because I figure most of the header options that I may install in the future include, or at least offer, the piping that go from the headers and cat "back" to the axle anyway. They all are made to bolt to pretty much any axleback that you have, but the pipes from a catback system, are definitely NOT likely to bolt right up to headers. I hope that makes sense.


The stock NPP, when wide open, is pretty much straight pipes, however when it passes through the big muffler/suitcase, the pipe is perforated. I'm no engineer, but it would certainly seem as though this did this to some how, acoustically knock down the volume. I've had straight piped systems before and they were MUCH much louder. My AWE touring has mufflers, and IT... is a bit louder than the track mode NPP. There's a guy in my neighborhood with a straight piped c7 z51 corvette (same LT1 engine) and you can literally hear him coming and going a mile or so away.

[njweatherman]

I currently have the Flowmaster American NPP axleback installed with the fuse pulled to keep it open all the time. Sounds good. I did it more for sound than anything else. I don't think I noticed any power gains. I will be installing the Flowmaster scavenger x-pipe soon for more sound. I will let you know if I notice anything.

[blkcamarossredline]

Thank you both so much for the help! It seems like there wouldn't be much of a sound or power increase with the cat back over the axle back due to the fact that the MBRP cat back still retains the secondary cats. I am also planning on doing headers in a few years so the axle back seems to make more sense.

[njweatherman]

IMO, the best way to determine speed and sound differences from OEM is to add one aftermarket part at a time.

[blkcamarossredline]

Originally Posted by njweatherman

IMO, the best way to determine speed and sound differences from OEM is to add one aftermarket part at a time.

I completely agree with you. My only concern is that the x pipe that comes with the MBRP cat back is only available with the cat back system and can't be purchased separately. At the moment I am just trying to decide whether or not the $300 dollars extra is worth it for the x pipe. Another question I have is if I decide to go the cat back route, will a 3 inch cat back have trouble with scavenging on a basically stock car, resulting in a loss of torque? Some other members on here have said that they felt that there were some dead spots once they installed the 3 inch cat back.

[Abubaca]

I'll double down on my two cents worth... ....I'd do axleback only. ...unless you wanna jump right into headers, in which case I'd do headers and X pipe and KEEP the stock NPP muffler/axleback, at least for now and see how you like it.

[njweatherman]

I don't know if a 3 inch catback will result in less torque on an otherwise stock car. I'm more of a sound guy. The larger diameter pipe will give you more sound. Have you looked at other systems like Flowmaster, Borla, Stainless Works, etc? They all have nice axleback and catback systems.

[blkcamarossredline]

Originally Posted by njweatherman

Have you looked at other systems like Flowmaster, Borla, Stainless Works, etc? They all have nice axleback and catback systems.

I have looked at other systems but I really like the sound of the MBRP and quite frankly the price.

[blkcamarossredline]

Originally Posted by Abubaca

I'll double down on my two cents worth... ....I'd do axleback only. ...unless you wanna jump right into headers, in which case I'd do headers and X pipe and KEEP the stock NPP muffler/axleback, at least for now and see how you like it.

Alright I am pretty sure I am going to go with the axle back. Later on I might either do an x pipe that deletes the secondary cats or I will do headers and the x pipe that goes with them.

[VinnAY]

The only reason to go catback IMHO is if you're deleting the secondary cats or somethign like that, headers, as stated. An otherwise catback will only deplete your wallet and do nothing else. Axle back for sound/volume/tone is relatively cost effective comparatively speaking.

[900RFWN]

Originally Posted by blkcamarossredline

Alright I am pretty sure I am going to go with the axle back. Later on I might either do an x pipe that deletes the secondary cats or I will do headers and the x pipe that goes with them.

Have you listened to the Solo Performance axle back? I think it sounds awesome and the price is good but would probably get rowdy real quick once you do cat deletes and/or headers.

[blkcamarossredline]

Originally Posted by VinnAY

The only reason to go catback IMHO is if you're deleting the secondary cats or somethign like that, headers, as stated. An otherwise catback will only deplete your wallet and do nothing else. Axle back for sound/volume/tone is relatively cost effective comparatively speaking.

That's exactly what I was thinking since the stock mid pipe comes with an x pipe and the MBRP cat back doesn't delete the secondary cats. The only thing that bothers me about the axle back is the fact that I will be leaving the crushed pipes but from what I have read they don't have an impact at stock power levels.

[Abubaca]

The only thing that bothers me about the axle back is the fact that I will be leaving the crushed pipes but from what I have read they don't have an impact at stock power levels.

I had the same concern, but countless numbers don't lie. Like you, I'll do all that if and when I go with headers. I swore this car wouldn't become another money pit that I couldn't sell or trade. We'll see how that goes. I'm fighting the good fight. Some days I win, some days I lose! LOL.