NPP Question
Thread Starter
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Joined: Jan 2013
Posts: 94
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From: Houston Texas
NPP Question
I understand that when you are more than 5000 rpm the NPP opens giving you the additional 6HP. Other wise with the remote opening the baffles it's just a noise thing. Question? In around town regular driving is there any other effect other than sound? Better or worse gas consumption? Performance at lower than 5,000 rpm? Also heard, maybe read on "Forum" that if you leave baffles in "open" position, less battery draw overnight. Thanks for input.
Melting Slicks
Joined: Aug 2011
Posts: 2,715
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From: Central Florida
I understand that when you are more than 5000 rpm the NPP opens giving you the additional 6HP. Other wise with the remote opening the baffles it's just a noise thing. Question? In around town regular driving is there any other effect other than sound? Better or worse gas consumption? Performance at lower than 5,000 rpm? Also heard, maybe read on "Forum" that if you leave baffles in "open" position, less battery draw overnight. Thanks for input.
Team Owner
Joined: May 2004
Posts: 82,175
Likes: 1,319
From: McKinney TX
St. Jude Donor '21-'22-'23-'24
And battery draw is based on how the NPP remote is wired up in the fuse box. If it's using both the seat heater fuse slot and the exhaust fuse slot, there's no battery draw.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
I understand that when you are more than 5000 rpm the NPP opens giving you the additional 6HP. Other wise with the remote opening the baffles it's just a noise thing. Question? In around town regular driving is there any other effect other than sound? Better or worse gas consumption? Performance at lower than 5,000 rpm? Also heard, maybe read on "Forum" that if you leave baffles in "open" position, less battery draw overnight. Thanks for input.
As to power, driving around town, etc. it's all either no effect, or very little (re mpg).
Battery drain covered above.
Pro
Joined: Jun 2012
Posts: 618
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I've even heard of issues with butterflies if you open them on your own and leave them open over time, like carbon build up or something.. Not sure I care much about that, but seems to make sense..
I've often forgotten to pull the fuse when tracking my Z, and I cannot ever tell a power difference.
It's a great feature but below 3500 it's all about sound. Sweet V8 sound.
I've often forgotten to pull the fuse when tracking my Z, and I cannot ever tell a power difference.
It's a great feature but below 3500 it's all about sound. Sweet V8 sound.
Safety Car
Joined: Nov 2007
Posts: 4,433
Likes: 873
From: Bay Area CA
I understand that when you are more than 5000 rpm the NPP opens giving you the additional 6HP. Other wise with the remote opening the baffles it's just a noise thing. Question? In around town regular driving is there any other effect other than sound? Better or worse gas consumption? Performance at lower than 5,000 rpm? Also heard, maybe read on "Forum" that if you leave baffles in "open" position, less battery draw overnight. Thanks for input.
2. Aftermarket switches, i.e. Mild2Wild has specific instructions on how to install a control switch with "0" drain battery method.
3. The oem default is open with engine off. This is due to no engine vacuum which keeps the valve open. No battery drain as oem.
Safety Car
Joined: Oct 2003
Posts: 4,024
Likes: 13
From: Loveland CO to Central Coast CA
I think the engine feels slightly sluggish & slightly less torquey with the NPP exhaust fully open at low rpm & light-throttle. 
Discussion and possible explanation:
http://forums.corvetteforum.com/c6-c...ower-loss.html
But there's no way to quantify this effect (if it even exists). It's all about how it feels.
So pull the fuse and drive it fully open. It won't hurt anything. Then decide for yourself.
Discussion and possible explanation:
http://forums.corvetteforum.com/c6-c...ower-loss.html
But there's no way to quantify this effect (if it even exists). It's all about how it feels.
So pull the fuse and drive it fully open. It won't hurt anything. Then decide for yourself.
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Thread Starter
Advanced
Joined: Jan 2013
Posts: 94
Likes: 5
From: Houston Texas
Npp
Thanks for the input. Think I'll leave in closed position and let the car perform as the engineers intended. Will use the open position at the drive in and when I feel like hearing the throaty rumble.
Pro
Joined: May 2011
Posts: 577
Likes: 8
From: Black Diamond Wa
I have the Exhaust Commander Elite from Sunset Orange Creations and I couldn't be happier with it. You can program your opening and closing points of the valves at any RPM you want or leave it open or closed. 3 modes of your choice. It's super easy to install and only takes 5 mins with no cutting. Great made in the USA product from a great vendor.
Melting Slicks
Joined: Aug 2011
Posts: 2,715
Likes: 1
From: Central Florida
I have the Exhaust Commander Elite from Sunset Orange Creations and I couldn't be happier with it. You can program your opening and closing points of the valves at any RPM you want or leave it open or closed. 3 modes of your choice. It's super easy to install and only takes 5 mins with no cutting. Great made in the USA product from a great vendor.
Instructor
Joined: Nov 2010
Posts: 216
Likes: 1
From: TN
I have the Exhaust Commander Elite from Sunset Orange Creations and I couldn't be happier with it. You can program your opening and closing points of the valves at any RPM you want or leave it open or closed. 3 modes of your choice. It's super easy to install and only takes 5 mins with no cutting. Great made in the USA product from a great vendor.
Safety Car
Joined: Apr 2004
Posts: 3,738
Likes: 10
From: Austin, Texas
Race Director
Joined: Sep 2008
Posts: 10,374
Likes: 128
From: Coventry RI
St. Jude Donor '13 thru '25
I have the M2W switch and I leave the valves open at all times except highway cruising. I get to hear the sweet sound of the exhaust and eliminate the drone that you get at cruising speed on the highway. The best of both worlds in my opinion. If there is a power difference I can not feel it..
Instructor
Joined: Nov 2010
Posts: 216
Likes: 1
From: TN
The instructions for installing the exhaust commander include the tap. I understand that the exhaust itself is a totally different install from that of the commander. Still would like to hear the "secret" from Stockcar Axeman. I plan an install next week.
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 25
From: Austin Texas
If you have an OEM NPP all you need to buy is a controller, 5 minute install.
If you are adding a complete NPP to a C6 you need the vacuum lines, the controller and the mufflers, much more than a 5 minute install.
Drifting
Joined: Feb 2013
Posts: 1,407
Likes: 48
From: Scottsdale Az
1. Opens around 3500 rpm which is where 6hp and 4 ft./torque start to benefit.
2. Aftermarket switches, i.e. Mild2Wild has specific instructions on how to install a control switch with "0" drain battery method.
3. The oem default is open with engine off. This is due to no engine vacuum which keeps the valve open. No battery drain as oem.
2. Aftermarket switches, i.e. Mild2Wild has specific instructions on how to install a control switch with "0" drain battery method.
3. The oem default is open with engine off. This is due to no engine vacuum which keeps the valve open. No battery drain as oem.
