[Bearded_Seamonkey]

Hello everyone. I was curious for those of you who have put an AWE exhaust on your ZL1…do you regret giving up the NPP? Even though it is through YouTube videos…I’m loving what I hear with the non-resonated touring catback. I’m planning to purchase it for my ZL1 1LE. I know some people want to keep the npp and others don’t care. I feel that I don’t “need” the npp and since I love the sound…I believe it is worth the trade off. Any input is greatly appreciated.

[CW3SF]

Originally Posted by Bearded_Seamonkey

Hello everyone. I was curious for those of you who have put an AWE exhaust on your ZL1…do you regret giving up the NPP? Even though it is through YouTube videos…I’m loving what I hear with the non-resonated touring catback. I’m planning to purchase it for my ZL1 1LE. I know some people want to keep the npp and others don’t care. I feel that I don’t “need” the npp and since I love the sound…I believe it is worth the trade off. Any input is greatly appreciated.

I pulled the NPP fuse before I left the dealership parking lot so I definitely have not missed it.

http://youtu.be/m3YpVq3ymJ0

[Z OH 6]

It really depends on how loud you like your exhaust. With the stock manifolds, the AWE exhaust sounds perfect. With headers and no cats, it can be extremely loud. Some people like that, some people don't

[clg82]

I love my borla for the exact reason of keeping the NPP....it has 0 drone at highway speeds....and if i want it louder I switch to sport mode and there you have it more sound.....I will add as well tho that I added a Mild 2 wild switch so that I can remotely turn the valves on and off with the push of a button.....no matter what mode i'm driving in.

[Dan82679]

Valves are a must for me on with 2" long tubes,no cats and magnaflow outlaw American thunder mufflers.Especially when I'm rolling down my street and backing into my garage.

[FRANK121]

I just got the AWE Touring cat back non resonated on mine a couple of weeks a go and absolutely love it! ZL1 is all stock with the exception of the Rotofab CAI.

Zero highway drone in fact can hardly tell the difference! Down shift or floor it and holy hell .... It sounds like a true muscle car now! .... Cold start is pretty loud now but I am blessed with pretty cool neighbors that are also hot rodders so they are cool with it!

I hear what others are saying about systems with Headers and that would probably too much but for now I wanted to increase the sound with a warranty.

https://youtu.be/O_dkCc0dmM4

[Crushed 1LE]

Originally Posted by FRANK121

I just got the AWE Touring cat back non resonated on mine a couple of weeks a go and absolutely love it! ZL1 is all stock with the exception of the Rotofab CAI.

Zero highway drone in fact can hardly tell the difference! Down shift or floor it and holy hell .... It sounds like a true muscle car now! .... Cold start is pretty loud now but I am blessed with pretty cool neighbors that are also hot rodders so they are cool with it!

I hear what others are saying about systems with Headers and that would probably too much but for now I wanted to increase the sound with a warranty.

https://youtu.be/O_dkCc0dmM4

I agree 100%. Zero drone on highway, but when you get into it, it sounds amazing. I am just on the dB limit at my local track. In fact when I had the PLP's installed I blew past the dB threshold. I removed them.

I don't miss the NPP at all. The AWE quality and fitment is excellent. The black diamond 4 inch tips are legendary Imo.

Go for it. You will not regret it.

[Domo14SS]

I don't miss NPP At all with my AWE Track Axleback. I will say though when I go to Headers, I'll most likely either sell the Track for an offering with NPP or go back to Stock. But for now, it sounds absolutely Perfect.

[warren3537]

I have the AWE Touring axle back and love it, most people think that I cammed it out which I haven't, 0 drone and the sound is amazing, so I don't miss the NPP.

[Z OH 6]

Originally Posted by warren3537

I have the AWE Touring axle back and love it, most people think that I cammed it out which I haven't, 0 drone and the sound is amazing, so I don't miss the NPP.

Funny you say that, my car sounds like its got a mild cam in it too especially when its cold. I have Kooks 2" headers, no cats and AWE touring catback exhaust so its pretty open, but I'm just amazed at how aggressive the stock cam is.

[Mac7504]

Does the npp system help with low end torque at all or is it simply to reduce the sound?

[Z OH 6]

Originally Posted by Mac7504

Does the npp system help with low end torque at all or is it simply to reduce the sound?

Reduce sound. Any restriction in the exhaust will only rob power, not add to it.

[Mac7504]

Originally Posted by Z OH 6

Reduce sound. Any restriction in the exhaust will only rob power, not add to it.

I supposed I was just thinking of my R6 ex up valves, where the variable system that eliminates dips in the torque development curve.

"Summary of the Mechanism
This is a system that employs a variable EXUP valve in the muffler that can change the configuration of the exhaust duct in a way that controls fluctuations in exhaust pressure at the moments of overlap between the intake and exhaust valves in order to improve intake efficiency, boost power output and improve fuel economy."

Of course that is a 4 stroke motor not a v8 but same concept.

[Z OH 6]

Originally Posted by Mac7504

I supposed I was just thinking of my R6 ex up valves, where the variable system that eliminates dips in the torque development curve.

"Summary of the Mechanism
This is a system that employs a variable EXUP valve in the muffler that can change the configuration of the exhaust duct in a way that controls fluctuations in exhaust pressure at the moments of overlap between the intake and exhaust valves in order to improve intake efficiency, boost power output and improve fuel economy."

Of course that is a 4 stroke motor not a v8 but same concept.

Not applicable to our cars. Exhaust scavenging has an effect on the torque curve and power but that happens in the manifold/header collectors. Everything after that is a potential restriction.