[Checkmate1]

Anyone do this?

I want to retain the stock exhaust box but curious if any muffler shops have done any wizardry with this box.

No muffler delete as I know drone is a huge issue with muffler deletes from owners.

[radz28]

You didn't state any reasoning behind this, but in case you hadn't seen or heard, but these mufflers pose little to no restriction and much loss of power. CSP performed a comparison with the stock axle back (AB) and AFE's AB (I believe it was that one...) and the gains were like a handful of horsepower on an 800-plus RWHP car. That AB also featured the NPP-valves so it was essentially open for the test, too.

Anyways - best of luck.

[Checkmate1]

Originally Posted by radz28

You didn't state any reasoning behind this, but in case you hadn't seen or heard, but these mufflers pose little to no restriction and much loss of power. CSP performed a comparison with the stock axle back (AB) and AFE's AB (I believe it was that one...) and the gains were like a handful of horsepower on an 800-plus RWHP car. That AB also featured the NPP-valves so it was essentially open for the test, too.

Anyways - best of luck.

My only reason is more sound. Not looking for performance gains.

Essentially, more sound with no drone.

I already have the Secondary CAT deletes done and it is marginally louder with more pops and crackles. That being said, I would like some more sound if it is easy enough for a muffler shop to handle.

[SouthFloridaGTO]

Originally Posted by radz28

You didn't state any reasoning behind this, but in case you hadn't seen or heard, but these mufflers pose little to no restriction and much loss of power. CSP performed a comparison with the stock axle back (AB) and AFE's AB (I believe it was that one...) and the gains were like a handful of horsepower on an 800-plus RWHP car. That AB also featured the NPP-valves so it was essentially open for the test, too.

Anyways - best of luck.

Not much HP, but it is a pretty significant weight reduction, as far as weight reduction goes on these cars.

[MarineZLE]

Originally Posted by Checkmate1

Anyone do this?

...curious if any muffler shops have done any wizardry with this box.

No muffler delete as I know drone is a huge issue with muffler deletes from owners.

You mean like the C6 Z06 muffler mod?

[Cleancoupe]

Originally Posted by SouthFloridaGTO

Not much HP, but it is a pretty significant weight reduction, as far as weight reduction goes on these cars.

To my surprise I didn’t save much weight at all getting rid of the factory exhaust.

Awe touring cat back non resonated with performance link pipes: 76.2lbs
Tips (4): 6.6lbs
Muffler (2): 29.2lbs
Mid pipes: 30.2lbs
Link pipes: 5.6lbs
Clamps: 4.6lbs

Factory NPP cat back: 79.2lbs
Muffler: 42lbs
Mid pipes & secondary cats: 37.2lbs

[JasonSB]

You want more sound then get headers. Headers and stock exhaust sound like ass. I added resonators right behind the stock suitcase which deleted the crushed section of the stock exhaust and it sounds good now. Im going to replace the stock tips with 4 inch black tips.

[Checkmate1]

No intention of getting headers or doing a muffler delete.

I am looking for something like the C6 Z06 muffler modification.

[radz28]

You could probably cut "doors" into the mufflers right above the perforated pipes are, weld-in non-perf' pipes, and weld the "door"s shut. That's the NPP-mod if I recall. In that case, though, you loose the benefits of the NPP, if I'm visualizing correctly.

FWIW - to the OP regarding replacing the OEM can: I think I read somewhere the OEM-can has some aero' that it contributes to (i.e. for the rear facia diffuser). There could be some thermal events but removing the can in extreme driving conditions (i.e. tracking). Having looked around there on mine, I can see what they're talking about, but it's whatever you prefer.

[TheRealJA105]

Unless you weld in cutouts before the suitcase, what you're envisioning won't do anything. Have you seen the NPP muffler cutaway? The outside pipes are a muffler bypass with only a few perforations in the piping.

[ramairroughneck]

Originally Posted by JasonSB

You want more sound then get headers. Headers and stock exhaust sound like ass. I added resonators right behind the stock suitcase which deleted the crushed section of the stock exhaust and it sounds good now. Im going to replace the stock tips with 4 inch black tips.

What length resonators did you use? I’d like to add 18” ones right after the X but they may be tough to fit. It’s looks close

[zincgt]

pull the npp fuse and it will keep the valves open 100%, my car is loud as hell on the outside but on the inside I wouldn't be able to tell. Its deceiving.

[Laststandard]

NPP exhaust cutaway. Really nothing to mod inside the case. I wouldn't attempt to replace the perforated section with a solid pipe, if you do that and happen to hook the NPP system back up bad things will happen.

Secondary cat delete will get a bit of extra sound.

[FoundNemo]

Connect the inlets to both of the outlet pipes and enjoy. Then you dont have to worry about what happens if you hook up NPP again.