NPP Exhaust?
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From: Providence RI
NPP Exhaust?
Curious to know more about the NPP Exhaust? Did a search for it but didn't get much results. Can anyone give a brief explanation of how it works? How worthy is the exhaust? Is it a must have? Thanks.
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St. Jude Donor '21-'22-'23-'24
Here's how it works:
http://forums.corvetteforum.com/1578087560-post5.html
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From: Providence RI
I sure do like it on my 08 coupe. I leave it open all the time except when I'm on the interstate. It was the main reason I bought my 08.
Here's how it works:
http://forums.corvetteforum.com/1578087560-post5.html
Here's how it works:
http://forums.corvetteforum.com/1578087560-post5.html
Questions: 1) Is the on/off switch in addition to the normal operation of the exhaust (throttle sensor and RPM's)? Or does the switch strictly control whether the baffles are opened or closed?
2) Is the price vs benefit more worth searching for a vette that currently has the NPP exhaust or better off adding an aftermarket cat-back exhaust? (If I am not mistaking the NPP exhaust is a factory installed option?)
Thanks!
Last edited by JuiceZ06; Mar 31, 2012 at 10:40 AM. Reason: need to add more...
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The sound is the big thing. Grumble, popping old time hot rod noise when open but stock quiet when closed. So, when the wife is in the car and we're on the highway, closed. In the city, I get to play and make vulgar noises!
Elmer
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St. Jude Donor '21-'22-'23-'24
There's a fuse in the passenger compartment fuse box that you can pull out and the flaps will stay open all the time. I did that for awhile before I finally decided to install and use the switch.
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From: Providence RI
So there is no factory installed switch when the NPP Exhaust option is included? If no switch, I am guessing the exhaust operates as it is explained in the link a few posts up (throttle sensor and RPM's)?
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No switch on factory install. There is a OEM controller that runs on RPM to open the flaps or loss of vacuum to open them. The NPP fuse as it come from the factory installation will control the flaps open/close. Open the circuit, flaps open, close the circuit, flaps close. That function can have a switch inserted in that circuit to give you an on/off switch for the NPP system. In my 2007, I have the fuse slot but no circuit to control the NPP. I use that slot for the voltage for the controller from suncoast creations to open/close my NPP.
Pro
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From: Carlisle, Iowa
No switch on factory install. There is a OEM controller that runs on RPM to open the flaps or loss of vacuum to open them. The NPP fuse as it come from the factory installation will control the flaps open/close. Open the circuit, flaps open, close the circuit, flaps close. That function can have a switch inserted in that circuit to give you an on/off switch for the NPP system. In my 2007, I have the fuse slot but no circuit to control the NPP. I use that slot for the voltage for the controller from suncoast creations to open/close my NPP.
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Elmer
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From: San Luis Obispo, California
My '12 GS came with NPP exh & I'm really happy with the system,loud when open, quiet when closed, albeit it looks pretty heavy.
The demo vette had SLP loudmouth cat back exhaust & it sounded just wicked, & the sales manager maintains the sytem does not drone at all & I believe him based on the design. It looked well built, with a high-flow through perforated chamber design like Borla, motorcycle exhaust, etc. & if my vette didn't have the NPP I would likely buy an SLP cat back system which is priced well @ <$700.
But...if you find a vette with the NPP then having the factory system is a nice bonus...I really like mine, & installed an 'add a switch' in the NPP fuse slot, & a rocker switch @ the glovebox, so I can turn it on/off at will (search forums & internet for instructions). The NPP system sounds very deep & throaty & burbles nicely on deceleration, but sounds very good WOT...but it was also a $1,200 factory ioption which is a bit pricey.
Good luck!
The demo vette had SLP loudmouth cat back exhaust & it sounded just wicked, & the sales manager maintains the sytem does not drone at all & I believe him based on the design. It looked well built, with a high-flow through perforated chamber design like Borla, motorcycle exhaust, etc. & if my vette didn't have the NPP I would likely buy an SLP cat back system which is priced well @ <$700.
But...if you find a vette with the NPP then having the factory system is a nice bonus...I really like mine, & installed an 'add a switch' in the NPP fuse slot, & a rocker switch @ the glovebox, so I can turn it on/off at will (search forums & internet for instructions). The NPP system sounds very deep & throaty & burbles nicely on deceleration, but sounds very good WOT...but it was also a $1,200 factory ioption which is a bit pricey.
Good luck!
Last edited by Bedouin; Apr 5, 2012 at 01:33 PM.
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Joined: Apr 2004
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From: Providence RI
My '12 GS came with NPP exh & I'm really happy with the system,loud when open, quiet when closed, albeit it looks pretty heavy.
The demo vette had SLP loudmouth cat back exhaust & it sounded just wicked, & the sales manager maintains the sytem does not drone at all & I believe him based on the design. It looked well built, with a high-flow through perforated chamber design like Borla, motorcycle exhaust, etc. & if my vette didn't have the NPP I would likely buy an SLP cat back system which is priced well @ <$700.
But...if you find a vette with the NPP then having the factory system is a nice bonus...I really like mine, & installed an 'add a switch' in the NPP fuse slot, & a rocker switch @ the glovebox, so I can turn it on/off at will (search forums & internet for instructions). The NPP system sounds very deep & throaty & burbles nicely on deceleration, but sounds very good WOT...but it was also a $1,200 factory ioption which is a bit pricey.
Good luck!
The demo vette had SLP loudmouth cat back exhaust & it sounded just wicked, & the sales manager maintains the sytem does not drone at all & I believe him based on the design. It looked well built, with a high-flow through perforated chamber design like Borla, motorcycle exhaust, etc. & if my vette didn't have the NPP I would likely buy an SLP cat back system which is priced well @ <$700.
But...if you find a vette with the NPP then having the factory system is a nice bonus...I really like mine, & installed an 'add a switch' in the NPP fuse slot, & a rocker switch @ the glovebox, so I can turn it on/off at will (search forums & internet for instructions). The NPP system sounds very deep & throaty & burbles nicely on deceleration, but sounds very good WOT...but it was also a $1,200 factory ioption which is a bit pricey.
Good luck!
Melting Slicks
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Very easy to wire it with an 'add-a-circuit' (NPP terminal goes on the LEFT side). Below is a pic of my '12 GS, but all Vettes are the same. And the circuit is still protected by the same 10A fuse you just removed. And further below a pic of the switch I installed. All in all, about $20 in parts. And MUCH better than a remote control IMO. Hope this helps.
Looking for other sites with less crappy moderators (and many members too, especially over the general forum), but if you need more help, send me a PM and I can send you a .pdf file with wiring instructions. Wish this place was like Ferrarichat as far as that, but with the tech knowledge here. Hopefully one of the other Vette sites has both.
Looking for other sites with less crappy moderators (and many members too, especially over the general forum), but if you need more help, send me a PM and I can send you a .pdf file with wiring instructions. Wish this place was like Ferrarichat as far as that, but with the tech knowledge here. Hopefully one of the other Vette sites has both.
Last edited by JCtx; Apr 7, 2012 at 06:30 PM.
Melting Slicks
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From: Summerton SC
Tech Contributor
Love it as well, I put my switch on the dead pedal. Anyone using headers with NPP, if so how does that sound (flaps closed & open)? Meaning, when open it is likely Thunderous as it should be, when closed maybe a touch louder or more than stock???
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From: Wilmington NC
This is true unless you install the vacuum reserve tank that comes standard on all Z06 and NPP optioned Vettes. I installed this reserve tank with the NPP installation on my 07 so the valves never open even under wot unless I purposely switch them open.
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Elmer
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From: Wilmington NC
and my original setup was the same and reacted the same. It was kind of a nice feature until I installed ARHeaders which greatly increased the sound and drone when the valves are open. It was fun to play with but when going on that long cruise and going up a long grade on the highway, the valves would start to open and the increased drone at that time became annoying fast. I gave Ben a call at SunsetOrangeCreations whose controller I use and he happened to have a vacuum tank in stock. Installation of the tank (it's fairly small) was a 15 minute job, it connects with a tee fitting to the vacuum line just before the vacuum controller (and after the check valve) which I installed in the passenger rear well compartment.
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From: Treasure Island Florida
St. Jude Donor '12-'13-'14
NPP exhaust update
If you end up going after market NPP, your least expensive route is to buy used Z06 NPP mufflers, do the muffler mod or have it done, then add the switch. I'm having the whole thing done and installed for less than I can buy a used DIY '08 NPP. They are hard to find.
Upadate: Just had my exhaust installed at FasterProms in Lutz, Fl. Hats off to Laz, who did a great job and showed me his secret lab where he does his manifold porting. Jeremy Formato, the owner, was a pleasure to do business with and gave me great advice for some street performance mods and tuning that I will be doing in a few months, after my warranty runs out. Thanks again Jeremy and Laz.
Upadate: Just had my exhaust installed at FasterProms in Lutz, Fl. Hats off to Laz, who did a great job and showed me his secret lab where he does his manifold porting. Jeremy Formato, the owner, was a pleasure to do business with and gave me great advice for some street performance mods and tuning that I will be doing in a few months, after my warranty runs out. Thanks again Jeremy and Laz.
Last edited by MikeBravo56; Apr 12, 2012 at 04:58 PM. Reason: Update