Dual Mode Exhaust
03-07-2011, 08:48 AM
#2
Burning Brakes
Check the RPO sticker on the inside of the glove box door. The code for dual-mode is NPP. Also, the mechanism is plainly visible above the exhaust pipes at the rear.
03-07-2011, 08:48 AM
#3
Go Canes!
There is an actuator on top of the inner pipes. Look at the back of the car. If you see muffler going into to chrome tips with nothing on top of it, they are not dual mode/NPP.
03-07-2011, 09:20 AM
#5
Safety Car
Member Since: Jan 2009
Location: Mooresville (Race City USA) NC
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The disc valves that actually close off and open up of the innermost tail pipes are clearly visible inside these pipes, but when the engine is off they are in the fully open position and are harder to see. Once the engine starts these valves normally close shut unless someone has pulled the fuse in the circuit that controls them, and are easily seen. Due to being in the open postion when the engine is started the exhaust sound is considerably louder than normal and then quiets down when the valves close almost immediately after engine start-up.
03-07-2011, 09:30 AM
#7
Melting Slicks
Optional NPP (non-Z06) Exhaust...
(Note: If this was a Z06 exhaust, there would be no perforation holes inside the tips.)
Standard C6 Exhaust...
(Note: If this was a Z06 exhaust, there would be no perforation holes inside the tips.)
Standard C6 Exhaust...
Last edited by Top_Fuel; 03-08-2011 at 01:47 PM.
03-07-2011, 09:48 AM
#8
Le Mans Master
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Great Photo
I can't imagine buying a new '08 or newer Vette without NPP, and with the "NPP in a box" installation kit, the NPP exhaust can be added to your '05 - '11 Vette if needed.
03-07-2011, 10:06 AM
#10
Instructor
Thread Starter
You guys are the best! The glove box data does show it came that way, but it also shows the polished wheels which are not currently on the car. I was concerned if they changed out the wheels, they may have done the same to the exhaust. Thanks.
03-07-2011, 12:11 PM
#11
Melting Slicks
03-07-2011, 02:29 PM
#13
Le Mans Master
The NPP actually produce a "better sound" Unless you Mod. the ZO6's
03-08-2011, 01:11 PM
#14
Melting Slicks
Not to start a pissing contest but the OP asked about Dual Mode, not NPP. Z06 are considered Dual Mode! You originally stated they were perforated,I simply stated that the Z06 were not. Therefore the visual clue the OP was looking for being perforations per your original post would have been wrong in the Z06 case.
Last edited by AmmoVet; 03-08-2011 at 01:19 PM.
03-08-2011, 02:16 PM
#15
Safety Car
Not to start a pissing contest but the OP asked about Dual Mode, not NPP. Z06 are considered Dual Mode! You originally stated they were perforated,I simply stated that the Z06 were not. Therefore the visual clue the OP was looking for being perforations per your original post would have been wrong in the Z06 case.
Anyway, it's interesting that the Z06 is not perforated. I bet they're easier to detail/keep clean.
Contest over?
03-09-2011, 09:36 AM
#16
Safety Car
, I read it the same way as you when OP said the "optional" dual mode exhaust.
03-09-2011, 09:42 AM
#17
Go Canes!
The OP never mentioned whether he was buying or he already had NPP. He just asked how to visually spot it!!! 
03-09-2011, 10:00 AM
#18
Instructor
Thread Starter
Yep, that was the case. I was looking to buy and did not know how to tell if dual mode was actually on the car (regardless of what the seller said). The car was quite a distance from me, so I wanted to be sure the claims were accurate. They were. As it turns out, there is no label in the glove box, but thanks to the photos, I could tell quickly that everything was exactly as represented by the seller. I picked up a 2009 yesterday! I'm sure many more questions will follow. My previous cars were C2s and one C3 many years ago before purchasing a C5 last year. Thanks again for your help.
03-09-2011, 10:40 AM
#19
Go Canes!
Yep, that was the case. I was looking to buy and did not know how to tell if dual mode was actually on the car (regardless of what the seller said). The car was quite a distance from me, so I wanted to be sure the claims were accurate. They were. As it turns out, there is no label in the glove box, but thanks to the photos, I could tell quickly that everything was exactly as represented by the seller. I picked up a 2009 yesterday! I'm sure many more questions will follow. My previous cars were C2s and one C3 many years ago before purchasing a C5 last year. Thanks again for your help.
Enjoy the new ride!! And, don't forget....
POST 'EM!!!!!
07-30-2014, 11:14 PM
#20
5th Gear
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I have a 2011 Grand Sport with standard exhaust. I'm saying it's standard because there are no actuators on top of the tailpipes and no valves visible inside the tailpipes. I have noticed that around 3500 rpms she really starts to sound good. Assuming I'm correct, and it is a standard, is there a good way to "wake-up" my Vette. Would just changing the mufflers to flomaśter or flowmax or to some other brand do the trick? What about electric cut ours?