[jimmypop13]

I think I was hoping NPP with the valves open would be like slp loudmouth or GMMG on a 4th gen f-body but its fairly tame to my ears. My gf has a v6 mustang with roush axlebacks that's way louder, lol. I think I'd rate this as medium on the volume scale for catbacks. What do y'all think?

[SS 1LE]

It's decently loud, removing the secondary, non o2 read cats will help make it louder. But you are comparing it to a Roush exhaust on a V6 Mustang, which is one of the louder Mustang exhausts. I had that on mine for a short time, as I hated the raspy tone, (and mines a 5.0) and switched it for Ford Racing set. Not sure how your girlfriend stands it on a V6, I've heard that exhaust on a few V6's, sounds awful.

[Reichler]

Interesting to see the "loudness" difference in the 5th Gen NPP vs the 6th Gen, but LT's and high flow or catless midpipes makes the 5th Gen NPP absolutely scream with the valves opened.

Not sure I like the big trash can of a muffler that they turned the NPP into now. If I were in the market for a new 16, I'd probably opt for the standard system and just swap in a new catback of my choosing later.

[BahamaTodd]

The NPP is only loud at higher rpm. Very quiet at idle. Probably legally required sound level limitations.

Companies are already coming out with long tubes and aftermarket NPP systems so there will be plenty of choices pretty soon.

[jimmypop13]

Originally Posted by SUMMIT WHITE SS

It's decently loud, removing the secondary, non o2 read cats will help make it louder. But you are comparing it to a Roush exhaust on a V6 Mustang, which is one of the louder Mustang exhausts. I had that on mine for a short time, as I hated the raspy tone, (and mines a 5.0) and switched it for Ford Racing set. Not sure how your girlfriend stands it on a V6, I've heard that exhaust on a few V6's, sounds awful.

Hey I didn't say the roush sounded good! Lol. But she likes it so that's all that matters.

I think the NPP sounds loud at idle, but it's not too loud on normal acceleration. Could be partially bc my car is an auto and not manual, but I'll definitely be looking into either an x-pipe that removes two cats or headers and xpipe

[SS 1LE]

Originally Posted by Reichler

Not sure I like the big trash can of a muffler that they turned the NPP into now. If I were in the market for a new 16, I'd probably opt for the standard system and just swap in a new catback of my choosing later.

I thought about that too, but I really want the quad tips and valence to go with it...not sure yet what I will do.

[SPARTAN sui]

Originally Posted by SUMMIT WHITE SS

I thought about that too, but I really want the quad tips and valence to go with it...not sure yet what I will do.

Plus the different modes, I'm really excited to try out the stealth mode. If I'm cruising late at night I don't want to piss off people that are trying to relax at home; or draw unwanted attention to myself.

I live in a small town and it's super annoying listening to a jacked up truck with straight pipes flooring it at every stop sign in town. I can hear those stupid trucks across town.

[jimmypop13]

Originally Posted by SPARTAN sui

Plus the different modes, I'm really excited to try out the stealth mode. If I'm cruising late at night I don't want to piss off people that are trying to relax at home; or draw unwanted attention to myself.

I live in a small town and it's super annoying listening to a jacked up truck with straight pipes flooring it at every stop sign in town. I can hear those stupid trucks across town.

Stealth mode works really well! You'll be pleased

[SPARTAN sui]

Awesome, I cannot wait!

[SS 1LE]

Originally Posted by jimmypop13

I think the NPP sounds loud at idle, but it's not too loud on normal acceleration. Could be partially bc my car is an auto and not manual, but I'll definitely be looking into either an x-pipe that removes two cats or headers and xpipe

Autos always are quieter typically as they tend to upshift into as high of a gear as possible. While a manual driver can hold a lower gear that will keep the revs up, and make the car louder.

[Tr6]

NPP is perfect for a BONE STOCK and 4 freaking cats. All modes work wonderful. I personally want more growl and sound thus getting a catless xpipe whenever they are available. Just so I can get rid of those un-monitored cats and add the wanted growl into it. Even right now the backfire is making me drool every time, I cannot wait to hear the LT1 even more

[SS 1LE]

Originally Posted by Tr6

NPP is perfect for a BONE STOCK and 4 freaking cats. All modes work wonderful. I personally want more growl and sound thus getting a catless xpipe whenever they are available. Just so I can get rid of those un-monitored cats and add the wanted growl into it. Even right now the backfire is making me drool every time, I cannot wait to hear the LT1 even more

Just go to an exhaust shop and have them cut out those two cats and weld in some stainless pipe...$75 - done.

[Reichler]

Originally Posted by Tr6

NPP is perfect for a BONE STOCK and 4 freaking cats. All modes work wonderful. I personally want more growl and sound thus getting a catless xpipe whenever they are available. Just so I can get rid of those un-monitored cats and add the wanted growl into it. Even right now the backfire is making me drool every time, I cannot wait to hear the LT1 even more

There aren't 4 cats. 2 cats and 2 resonators. Same as the 5th Gens.

[titanfan]

Please do not equate "loud" with "good". I've heard a lot of loud cars that sounded like crap.