[2fun]

I have a 2015 C7 on order with the performance exhaust (Z51, 3LT, magnetic ride, manual trans plus other goodies). I have driven a C7 and think the exhaust is too quiet and would like to make the stock exhaust louder. Does anyone know if there are any modifications I can do to it like the C6 muffler modification where you cut open the muffler and weld a straight pipe over the perforated one to create a "straight through" design? I had 2008 Z06 and did that modification. It was perfect. Definitely louder than stock but still quiet on the inside when the butterflies were closed. I will also be adding a supercharger to the car in the next 60 days or so. Thanks for your help.

 

[Mobius]

Does anyone know if there are any modifications I can do to it like the C6 muffler modification where you cut open the muffler and weld a straight pipe over the perforated one to create a "straight through" design? I had 2008 Z06 and did that modification. It was perfect.

My understanding is that when the NPP valves are open you have a straight-shot for the exhaust, effectively bypassing the muffler. This is one of the main reasons the outer exhaust tips get so dirty, while the two inner tips remain clean. I've been running in Track mode for the last few weeks, and the outer exhaust tips get black after every few, good 3 hour drives, while the inners have nothing.

 

[jsvette]

I've been running in Track mode for the last few weeks, and the outer exhaust tips get black after every few, good 3 hour drives, while the inners have nothing.

I am surprised by that. The only time RedHot's outer tips get any black is on a short drive where the car only just warmed up. On regular and long drives (my NPP is set to be always open regardless of Mode) there is no accumulation on the tips.

 

[Ragtop]

Drill holes in mufflers. Makes them louder.

 

[Rich427]

I have a 2015 C7 on order with the performance exhaust (Z51, 3LT, magnetic ride, manual trans plus other goodies). I have driven a C7 and think the exhaust is too quiet and would like to make the stock exhaust louder. Does anyone know if there are any modifications I can do to it like the C6 muffler modification where you cut open the muffler and weld a straight pipe over the perforated one to create a "straight through" design? I had 2008 Z06 and did that modification. It was perfect. Definitely louder than stock but still quiet on the inside when the butterflies were closed. I will also be adding a supercharger to the car in the next 60 days or so. Thanks for your help.

From your comments, I cannot tell what mode the car was in during your ride. I hope you know that unless you go into the system and override, the NPP exhaust is quieter in Touring, Eco and Weather modes, and is louder in Sport and Track modes. I would suggest that you don't make plans to modify your exhaust until you have had some time to play with your new car and the various modes, and exhaust sounds for these modes. Just my opinion!

 

[2fun]

Good info. I am looking for a way to make the NPP exhaust louder than it currently is in sport and track mode. My c6 z06 had "straight through" pipes also however they were perforated so we cut open the top of the muffler and welded a "solid" pipe over the perforated pipe making the exhaust louder. Then welded the top of the muffler back on. I am curious if anyone has tried this on their C7 or have another way to make the NPP exhaust louder.

 

[cjenkinsC7]

What do you clean the exhaust with ?

 

[jsvette]

What do you clean the exhaust with ?

See http://www.stingrayforums.com/forum/stingray-corvette-discussions/5409-why-only-outside-tail-pipes-dirty.html post #2

 

[thrilled]

I had heard of taking A 1/2 " to A 1" pipe and running it thru the muffler to the cats.Supposely giving it more room to breathing and more sound.Might have throwing code issues with NPP.

 

[skdiablo]

Has anyone figured this one yet? I also had the similar thing done to my c6 z06 mufflers. Wondering if it also works on c7.

 

[C7Jake]

Get sawzall...remove mufflers...toss in dumpster
Buy 4.5" tips + 25sq' of Rattletrap Xtreme
Project cost $500...sold stock tips for $80
AFM valves retained...fascia not removed

 

[Fish]

Nice

 

[Z06 Owned]

Get sawzall...remove mufflers...toss in dumpster
Buy 4.5" tips + 25sq' of Rattletrap Xtreme
Project cost $500...sold stock tips for $80
AFM valves retained...fascia not removed

C7 Jake...how happy are you with the sound deadening treatment? Haven't done mine yet, but it needs to be done.

 

[C7Jake]

C7Jake...how happy are you with the sound deadening treatment?

Very worthwhile

 

[thrilled]

I just went and did after market muffler B+B.But it has A good sound.Not cheap.$1,300 not including labor.

 

[abshapiro]

Here is a link on car exhaust theory. It's a nice read but gives you more information than you probably want.

Exhaust Theory | NSX Prime

 

[mclarenracer22]

Does anyone know if the NPP mufflers on the C7 are similar to C6NPP mufflers to even do the same mod?

- Thanks