Dual Mode Exhaust
Thread Starter
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Dual Mode Exhaust
Hey Guys,
I'm selling my 94 ZR-1 and stepping into a 2LT 2012 Grand Sport. It is not equipped with the dual mode exhaust. Can that be added without a lot of hassle and do they come up for sale here?
As you can tell I'm brand new to the C-6 stuff having two C-4's (including the Z) since 1992..
Thanks
I'm selling my 94 ZR-1 and stepping into a 2LT 2012 Grand Sport. It is not equipped with the dual mode exhaust. Can that be added without a lot of hassle and do they come up for sale here?
As you can tell I'm brand new to the C-6 stuff having two C-4's (including the Z) since 1992..
Thanks
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
It can be added but it won't have the automatic functionality of a factory setup.
Assuming you want the dual mode function to work you will need some type of vacuum control system in addition to the mufflers themselves. We have few vendors that sell what is commonly referred to as "NPP in a Box" which will give you a vacuum source hookup and remote manual control. Here are a couple threads to read to get you started:
http://forums.corvetteforum.com/c6-c...st-choice.html
http://forums.corvetteforum.com/c6-c...p-exhaust.html
You also have a choice with the mufflers. You can use the NPP's or Z06 mufflers. The difference is the Z06's are a milder sound.....but even that can be modded by cutting the mufflers open and welding covers over the perforated pipe inside each one. Used Z06 mufflers usually sell for much less than the NPP mufflers. Most folks prefer the NPP's because they are louder and harsher than the Z06's, personal preference. And yes, keep an eye on the Parts section and the auction site, take offs come up for sale fairly often.
Assuming you want the dual mode function to work you will need some type of vacuum control system in addition to the mufflers themselves. We have few vendors that sell what is commonly referred to as "NPP in a Box" which will give you a vacuum source hookup and remote manual control. Here are a couple threads to read to get you started:
http://forums.corvetteforum.com/c6-c...st-choice.html
http://forums.corvetteforum.com/c6-c...p-exhaust.html
You also have a choice with the mufflers. You can use the NPP's or Z06 mufflers. The difference is the Z06's are a milder sound.....but even that can be modded by cutting the mufflers open and welding covers over the perforated pipe inside each one. Used Z06 mufflers usually sell for much less than the NPP mufflers. Most folks prefer the NPP's because they are louder and harsher than the Z06's, personal preference. And yes, keep an eye on the Parts section and the auction site, take offs come up for sale fairly often.
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
Here's another vendor selling the original NPP in a Box system:
http://www.topflightrepro.com/corvet...formance.shtml
http://www.topflightrepro.com/corvet...formance.shtml
Drifting
Joined: Apr 2001
Posts: 1,779
Likes: 6
From: LOS ANGELES CA.
Npp Exhaust
I don't think theNPP exhaust is worth the money.You have to rev up pretty high thru the gears to open the npp.I have it on my car.It came with it but it seldom opens up.Just my 2 cents.Rod 
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 26
From: Austin Texas
The NPP is an excellent exhaust and can be bolted directly to your existing mid-pipe if you purcahse a 2009 or newer NPP. You can buy it new from a Dealer ($1100+) or used from CF Parts for Sale ($650 to $900). Maybe run a WTB ad in the Parts For sale section?
You'll also need a controller for the exhaust also since your car doesn't have the computer control, I suggest the one from http://sunsetorangecreations.com/
You'll also need a controller for the exhaust also since your car doesn't have the computer control, I suggest the one from http://sunsetorangecreations.com/
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 26
From: Austin Texas
You need a controller for the NPP so you can open the exhaust when YOU want instead of when the computer wants.
Or just pull the fuse and run the exhaust open all the time.
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Melting Slicks
Joined: Jul 2010
Posts: 3,001
Likes: 243
From: Surprise, Az
I love the NPP exhaust. Its quiet most of the time as there is enough road noise already. Its great to hear it open up when I'm on the road course at Pacific Raceways or get a little aggressive when getting on the freeways around here. It opens about 3500 rpm's which is about perfect IMO. The car is pretty quiet until I jump on it and it roars to life!
Racer
Joined: Apr 2006
Posts: 495
Likes: 1
From: Valley Stream NY
I love the NPP exhaust. Its quiet most of the time as there is enough road noise already. Its great to hear it open up when I'm on the road course at Pacific Raceways or get a little aggressive when getting on the freeways around here. It opens about 3500 rpm's which is about perfect IMO. The car is pretty quiet until I jump on it and it roars to life!
Safety Car
Joined: Jul 2006
Posts: 4,325
Likes: 0
From: You can't get there from here NJ
St. Jude Donor '08-'09
I have an 06 vert. After I got it, I found a ZO6 exhaust for $450 with h- pipe. I found ZO6 manifolds and cats, and had the whole system installed with an NPP in a box controler. I change from one to the other when I want to. At about 3000 rpms, with the Vararam intake I have on the car, the whole system just seems to come alive, and the sound is sweet. Yes, you can go to this system from stock. Also, I might add, the ZO6 system is 3" pipe from front to back. I'm not sure, but the stock NPP may be 2 1/2 ", not 3 ".
Burning Brakes
Joined: Dec 2007
Posts: 860
Likes: 75
From: Corona CA
I have an 06 vert. After I got it, I found a ZO6 exhaust for $450 with h- pipe. I found ZO6 manifolds and cats, and had the whole system installed with an NPP in a box controler. I change from one to the other when I want to. At about 3000 rpms, with the Vararam intake I have on the car, the whole system just seems to come alive, and the sound is sweet. Yes, you can go to this system from stock. Also, I might add, the ZO6 system is 3" pipe from front to back. I'm not sure, but the stock NPP may be 2 1/2 ", not 3 ".
To the OP: Do a search and you will find much more info on the addition of the NPP to a non-NPP 'Vette, and Z06 exhaust conversion..
Racer
Joined: Mar 2006
Posts: 265
Likes: 3
From: Metamora, IL
Congratulations on your new car! I put the NPP on my car with AR headers. It is quiet on the road (no drone) when closed, but when I want it, I can have the sweet music of the LS3 to get my Corvette fix. Sound is very personal, but all my friends sure like the way it sounds. I highly recommend the NPP system.
Safety Car
Joined: Jul 2006
Posts: 4,325
Likes: 0
From: You can't get there from here NJ
St. Jude Donor '08-'09
You are correct. The system will bolt right up to a manual car. An auto tranny car is another story, and will require modifying the over-the-axle pipes to fit. The Z06 system is quieter than the NPP system, unless you mod the Z06 mufflers by cutting them open and seal the perforated pipe. Also, the Z06 system is 3", but necks down to 2 1/2" right before the muffler. NPP is 2 1/2". The full Z06 system will give you more power than the NPP.
To the OP: Do a search and you will find much more info on the addition of the NPP to a non-NPP 'Vette, and Z06 exhaust conversion..
To the OP: Do a search and you will find much more info on the addition of the NPP to a non-NPP 'Vette, and Z06 exhaust conversion..
The ZO6 system that I have sounds loud enough for me. When the revs drop to about 1800, it does drone very noticeably, and requires a downshift to avoid this, but I usually have it in the open position, and everyone, even my GF likes the way it sounds. At highway speeds, I usually stay in 5th, or just hit the button on the NPP in a box to get rid of the drone. I wasn't aware of the fact that the stock NPP was louder. The ZO6 one is fine for me.
Drifting
Joined: Jan 2006
Posts: 1,554
Likes: 158
I wouldn't let the lack of NPP be a deal breaker nor would I modify a new car to add it. Better to buy a Corvette with it as a factory option. If it isn't factory it may be a headache. It does sound good but you have to punch the car to get the RPM's up pretty high for NPP to kick in. NPP comes on for a moment when you first start the car but quiets back down quickly. I got NPP on my car not so much for the sound as the "performance exhaust" adds 6 HP.
Race Director
Joined: Mar 2007
Posts: 11,331
Likes: 18
From: Missouri City Texas
Adding NPP and the functionality of it is VERY simple.
Put the exhaust on and then run a rubber hose up to a vacuum line. No big deal and you don't need to spend money on the NPP in a box thing if you just want it to open and close like factory.
My shop installed Z06 mufflers with the full 3" overaxle piping on my A6 car and ran the vacuum line for $150 bucks. If I want it open all the time I just pull the vacuum line off and plug it. Takes about 30 seconds.
I tend to just let it open and close as it sees fit though. As soon as my car hits boost they open right up.
Put the exhaust on and then run a rubber hose up to a vacuum line. No big deal and you don't need to spend money on the NPP in a box thing if you just want it to open and close like factory.
My shop installed Z06 mufflers with the full 3" overaxle piping on my A6 car and ran the vacuum line for $150 bucks. If I want it open all the time I just pull the vacuum line off and plug it. Takes about 30 seconds.
I tend to just let it open and close as it sees fit though. As soon as my car hits boost they open right up.
Melting Slicks
Joined: Nov 2005
Posts: 2,345
Likes: 2
From: Houston 06 C6 Ysi SC 402 fgd TX
Adding NPP and the functionality of it is VERY simple.
Put the exhaust on and then run a rubber hose up to a vacuum line. No big deal and you don't need to spend money on the NPP in a box thing if you just want it to open and close like factory.
My shop installed Z06 mufflers with the full 3" overaxle piping on my A6 car and ran the vacuum line for $150 bucks. If I want it open all the time I just pull the vacuum line off and plug it. Takes about 30 seconds.
I tend to just let it open and close as it sees fit though. As soon as my car hits boost they open right up.
Put the exhaust on and then run a rubber hose up to a vacuum line. No big deal and you don't need to spend money on the NPP in a box thing if you just want it to open and close like factory.
My shop installed Z06 mufflers with the full 3" overaxle piping on my A6 car and ran the vacuum line for $150 bucks. If I want it open all the time I just pull the vacuum line off and plug it. Takes about 30 seconds.
I tend to just let it open and close as it sees fit though. As soon as my car hits boost they open right up.
Just to clarify-------you paid for the Z06 exhaust and then $150 for the install?
Here in Houston, a few years ago a shop on north side of town did a lot of Z06 upgrades to bullets, corsa, borla, etc, there was a big pile of Z06 mufflers out back, they were practically giving them away back then.
Advanced
Joined: Dec 2013
Posts: 81
Likes: 0
No is awesome
Pull the fuse, or get the remote or get the old school dead pedal switch . I have dead pedal, and I love it. My 2 cents
Advanced
Joined: Mar 2015
Posts: 79
Likes: 3
From: winter fl
Do you have any drone at around 2000 RPM? I am asking because I took off the axle back. So, it was stock all the way before the last section, with the over-axle pipe and mufflers. I took off this last section and drove my C6 2008 manual around town. When reaching 1800 - 2000 RPM (like when shifting from 1st to 2nd gear), even slowly, the drone inside the cabin was so loud that I couldn't actually hear the great sound generated outside. I was thinking that, perhaps with the cutouts, since the rest of the system remains unchanged, the part behind the cutout "acts" kinda like a Helmholtz resonator (also known as branch resonators) and would eliminate this drone.
Anyone has thoughts about this???