Seems like an awful lot of money for some butterfly flaps?
Why not just purchase an after market exhaust and even save some money?
New exhaust can be had for <1K.
Interested in opinions.

 

I think the beauty of the dual mode/NPP is in it's adjustability. I think it sounds good in all modes but I have it set to not close all the way. It doesn't drone like that but it's not quite as quiet as it was.

I don't like real loud. I think I paid $1200 for the option. I haven't checked but is there a dual mode aftermarket system that can be had for that $?

 

Huh? Getting the NPP eliminates the need for expensive after market systems that will cost even more in most cases. And it's factory!!

 

The reason to pay the freight for NPP is so that you can add a Mild to Wild and open or close it at will. An after market exhaust will come without installation and I believe most cannot be turned on or off.

If you add the cost of installation and the ability to turn the system on and off, I think you will see that there is no savings by purchasing a quality after market system.

I like to turn my system off on long trips and under certain low RPM conditions where exhaust drone can be induced.

 

I have not yet heard an aftermarket exhaust that sounds as good/better than an open NPP, but won't drone your brains out during cruising.

If you only use the car as a weekend toy, then an always-loud exhaust might be ok. But for long trips or a DD, it's awful.

 

How have you accomplished this, collared spacers or something?


Discussing a loud exhaust citation on another thread consider this. NPP/M2W lets you say "but it's factory officer".

Imagine a Judge telling you removing the spendy aftermarket exhaust is required to be in compliance.

 

Collars that fit on the control rod that can be tightened to and spot you choose and that will hold the flaps open at any percentage for the sound you like. I have them but my system is on/off. On for city and noise (sans wife) Off (closed) for highway driving (with wife) and quiet and no drone.

A lot of aftermarket is loud and drone with no control over the sound OR drone. I tried B&B Beer can mufflers, B&B Route 66, and found the manually controlled NPP to give me the best of both worlds.

Elmer

 

So you have mild to wild along with the collars?

 

Could be wrong but I think OP is talking about the cost of ADDING factory style NPP to existing Vette vs. cost of other systems.

 

corsa on both my vettes no drone

 

Since most people refer the NPP's in open position, the SLP powerflo has a similar sound for half the price.

 

I would say I would agree until I installed my Borla ATAK system. I had NPP and liked the sound but went with a full Z06 exhaust to get a little more power. I modded the Z06 cans but it wasn't the same. I tried B&B bullets but they droned way too much for me. I then tried the GHL street series which again droned too much for me.
I then installed the new Borla ATAK system and have to say this is the best system I have heard so far, no drone and great sound. But, at price, $1800.00 is not really all that cheap for an exhaust.
You can easily cruise and talk to your passenger (This is important for my wife.) and just enjoy your car.


DJ

 

Yes, I bought the NPP from a member on this forum and it came with the collars. I have them basically "off" and they don't control the flaps in any way. I go on/off via a button push on a sunvisor button.

 

Thanks for the info.

Anyone thinking of an aftermarket system should try to find a Borla ATAK system they can listen to.

 

The one from sunset creations? Been considering the one they have where you can set the rpm it opens. But also like what you have with the collars along with the switch. You like the visor button better that the remote then...?

 

I should have added that I have GHL's on my C5 and am very happy with them.
Brand new GHL's are available for the C6 for less than 1k and are incredibly simple to install.
Glad to hear people are fairly happy with the NPP option.

 

Yes, the sunset creations is what I have. Visor button says you don't have to find the FOB or have the FOB dangling somewhere convenient. The visor button also eliminates the FOB battery issue.

 

The only other alternative to NPP (for a bi-mode exhaust) seems to be the B & B Fusions. And they are actually more expensive.

The reason we put NPP exhaust on the car is solely for the ability to adjust the sound. Otherwise, we would just find a muffler with the sound we like (Corsa, Borla, Magnaflow, etc.) and put it on.

In my opinion, installing the NPP or the Fusions and leaving it on one setting kind of defeats the purpose of the adjustability or the bi-mode feature.

I have my NPP - I bought it used here on CF - and it's controlled with a kit from Sunset Orange Creations, which is synched to the sun visor controls.

 

Granted, what sounds 'good' is in the ear of the beholder. For me, sound is an integral part of the performance car experience and sadly stock Corvettes sound weak. I realize there are government constraints and Corvette tries to appeal to a certain demographic but even a Mustang sounds better. While I commend GM for trying to address the poor sound quality of the Corvette I've never been a fan of the NPP exhaust. It's mechanically 'gimmicky' and frankly doesn't sound as good as certain aftermarket exhausts. I want a high performance car to sound like one 24/7....not a part-time exhaust the only sounds (somewhat) better in a certain RPM range. With the NPP exhaust many opt for the aftermarket 'switched' exhaust feature and many others simply leave the valves open all the time. This IMO evidences the NPP is lacking straight from the factory. Conceptually, I think flipping a switch to change the volume of your car is hokey. If I want my car to be louder I'll press my right foot down.

I think you're much better off going with a quality aftermarket exhaust such as made my Corsa or Borla. Some aftermarket exhausts try to mimic the muscle car sound but often come-off being loud and obnoxious. I want a drone-free exhaust that generates a strong, clean exhaust note reflective of what's under the hood. Keep in-mind if you make future engine modifications it will effect the sound of an exhaust greatly. If you're undecided arrange to visit a local Corvette club gathering or a nearby road course venue and listen to various Corvette exhausts firsthand. Good luck whatever you decide on.

 

One more point, the NPP if set to quiet will open up if you go WOT. The WOT will take the vacuum down to 0 and the vacuum is what holds the flaps closed. So you get loud if you hit the throttle hard. There is a way to remain quiet during WOT but you need to hook in a vacuum reservoir to hold the flaps closed during WOT. I don't have that. If I go WOT or into boost, the flaps open up and it gets noisy back there.

Also note, I have LT headers and no cats. It would be very loud and have drone with most aftermarket systems. The NPP makes it "stock" quiet when the flaps are closed.

Elmer