npp
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Pro
Joined: Feb 2011
Posts: 535
Likes: 20
From: TX
NPP fuse
It is in the panel behind the carpet on the passenger side. It easily pulls back from the top behind the firewall area.
Click on search this forum near the top of the general discussion page next to forum tools. Type in fuse photo and scroll down to Tool for pulling NPP fuse. From there scroll about half way down that page to photo with arrow pointing to the fuse. Buy the mild to wild switch, it just plugs in where the fuse is/was and you are done. At some point in time you will want it quiet I promise. Probably a 30 second install.
Click on search this forum near the top of the general discussion page next to forum tools. Type in fuse photo and scroll down to Tool for pulling NPP fuse. From there scroll about half way down that page to photo with arrow pointing to the fuse. Buy the mild to wild switch, it just plugs in where the fuse is/was and you are done. At some point in time you will want it quiet I promise. Probably a 30 second install.
Last edited by GRG; Sep 29, 2011 at 06:16 PM.
Drifting
Joined: May 2011
Posts: 1,728
Likes: 36
From: TX / CO
My version except with B & B Fusions and a 500+whp N/A build. Nice thing about the Fusions is it comes with a remote to open and close the valves.
http://www.youtube.com/watch?v=Poc65pfbxkI
http://www.youtube.com/watch?v=Poc65pfbxkI
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 25
From: Austin Texas
Team Owner
Joined: Mar 2007
Posts: 35,134
Likes: 2,092
From: Right Corner Pocket of Illinois
No-IL Events Coordinator
2026 Corvette of the Year Finalist - Unmodified
2025 C6 of the Year Winner - Unmodified
2020 C6 of the Year Finalist - Unmodified
2020 Corvette of the Year Finalist (appearance mods)
2019 C6 of Year Winner (appearance mods)
2018 C6 of Year Finalist
St. Jude Donor '12 thru '26
Do I understand correctly that the air/fuel ratio changes when the dual mode goes to the open position???
Team Owner
Joined: Feb 2000
Posts: 45,193
Likes: 892
From: Texas
CI 1-4-5-8-9-10 Vet
St. Jude Donor '03 thru '10, '17
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Thread Starter
Instructor
Joined: Nov 2008
Posts: 231
Likes: 1
From: MPHS TN
thanks every one for your help, I'm always learning, that why I turn to CF.
Team Owner
Joined: Mar 2007
Posts: 35,134
Likes: 2,092
From: Right Corner Pocket of Illinois
No-IL Events Coordinator
2026 Corvette of the Year Finalist - Unmodified
2025 C6 of the Year Winner - Unmodified
2020 C6 of the Year Finalist - Unmodified
2020 Corvette of the Year Finalist (appearance mods)
2019 C6 of Year Winner (appearance mods)
2018 C6 of Year Finalist
St. Jude Donor '12 thru '26
OK, thanks (thought sure I read it did somewhere).
Originally Posted by Halltech
The Tech 2 shows no change in long term fuel trims with the switch on or off. This means the combustion process does not change with the exhaust bypass open.
There is an increase in torque with the fuse pulled, in the open position below 3500 rpm normal mode and 3000 rpm competition mode. We saw this on the dyno Jan 06, and the Donaldson folks acknowledged it.
The Wideband was put in the outside exhaust pipes, and at 3500 rpm, our air/fuel ratio disappeared. So.....out came the fuse so we could stick the sensor in the middle exhaust with the bypass valve open. Bingo. You could see a definite increase in torque below 3500 rpm, which was attributed to the open exhaust.
Fuel mileage? It should actually increase mpg slightly, since opening the exhaust actually helps fuel mileage.
The Tech 2 shows no change in long term fuel trims with the switch on or off. This means the combustion process does not change with the exhaust bypass open.
There is an increase in torque with the fuse pulled, in the open position below 3500 rpm normal mode and 3000 rpm competition mode. We saw this on the dyno Jan 06, and the Donaldson folks acknowledged it.
The Wideband was put in the outside exhaust pipes, and at 3500 rpm, our air/fuel ratio disappeared. So.....out came the fuse so we could stick the sensor in the middle exhaust with the bypass valve open. Bingo. You could see a definite increase in torque below 3500 rpm, which was attributed to the open exhaust.
Fuel mileage? It should actually increase mpg slightly, since opening the exhaust actually helps fuel mileage.
Team Owner
Joined: Feb 2000
Posts: 45,193
Likes: 892
From: Texas
CI 1-4-5-8-9-10 Vet
St. Jude Donor '03 thru '10, '17
I think they are just referring to the slight increase in TQ & HP due to the reduced backpressure. Admittedly, it must be a small increase since we are talking about an increase in HP from 430 to 436.
I would guess that if you asked a GM engineer, they would tell you that there is no change to the fuel map when the NPP opens.
I would guess that if you asked a GM engineer, they would tell you that there is no change to the fuel map when the NPP opens.
Pro
Joined: Jul 2010
Posts: 698
Likes: 2
From: Memphis TN
St. Jude Donor '11-'12-'13-'14-'15-'16-'17
Hold your position...
Nice come back. Keep up the good work. I'm sure the group appreciates your effort.
Chaplain
Chaplain
Pro
Joined: Sep 2005
Posts: 721
Likes: 2
From: Fort Worth TX
Glad I ran across this tonight! Best free mod! Went right back into the garage and yanked my fuse, went for a cruise loving the new sound! Just need to do something about all the popping now when I release the throttle here I come X-Pipe.