[Ribak433]

I was doing some research on aftermarket exhaust systems/mufflers available for the 2SS. I keep running into an issue with the NPP. Apparently, for some reason, you can get aftermarket mufflers for non-NPP cars only. What would be the reason behind this? And if this is the case, should I order my car without the NPP and use aftermarket exhaust? Or are the benefits equivalent to the NPP? IMO, the less "moving" parts, the less chance for future problems! Also, how is the NPP controlled? Vacuum, electrically, etc.....?

[jdasnt3]

Controlled electrically. If you want aftermarket exhaust and sound, don't order with the $800 NPP option. I personally love it and the flexibility. If I want it quiet, no problem. Loud, no problem.

My 15 SS had an axle back. It was loud and sounded good except at 73-77MPH on the interstate. Too much drone.

[Ribak433]

Okay, don't mean to sound like a moron..... But I've heard that terminology thrown around. What exactly is everyone referring to as "drone"?

[jdasnt3]

Originally Posted by Ribak433

Okay, don't mean to sound like a moron..... But I've heard that terminology thrown around. What exactly is everyone referring to as "drone"?

A loud vibration and humming sound that rattles your car. Very annoying. Mine used to drown out conversations and also make you have to crank up the radio or go faster or slower than the speeds that caused it. So on the interstate with a limit of 70, I had to do 70 or 80 and nothing in between. The NPP exhaust was tuned for this car to specifically make sure that there wasn't drone at any speed. The axle back brand I used to have on my 15? GM Performance. Figured there would be no drone, and I was wrong.

[SS 1LE]

Originally Posted by jdasnt3

A loud vibration and humming sound that rattles your car.

That sounds like something else lol...

Drone is just a resonant frequency that is some cars at certain rpms can make for a constant, droning sound. Hence the term "drone"...some actually are okay with it, others hate it.

[jdasnt3]

Originally Posted by SUMMIT WHITE SS

That sounds like something else lol...

Drone is just a resonant frequency that is some cars at certain rpms can make for a constant, droning sound. Hence the term "drone"...some actually are okay with it, others hate it.

Should have said rattles your brain...

[Jeremeymt]

Originally Posted by Ribak433

I was doing some research on aftermarket exhaust systems/mufflers available for the 2SS. I keep running into an issue with the NPP. Apparently, for some reason, you can get aftermarket mufflers for non-NPP cars only. What would be the reason behind this? And if this is the case, should I order my car without the NPP and use aftermarket exhaust? Or are the benefits equivalent to the NPP? IMO, the less "moving" parts, the less chance for future problems! Also, how is the NPP controlled? Vacuum, electrically, etc.....?

Get NPP and then pull the fuse. That way the valves will stay open all the time. I have the v6 and the NPP sounds awesome with the fuse pulled. Unless you want to make it quiet sometimes then don't pull the fuse.