NPP-Basic Question
Thread Starter
Intermediate
Joined: Aug 2017
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NPP-Basic Question
Sorry for the very basic question and I apologize if it has already been covered.
Aside from the sound potentially becoming annoying on long road trips, are there any other mechanical or functional concerns regarding running all 4 exhausts open most or all the time?
I imagine there isn't but I want to make sure before I start growling up my neighborhood!
Aside from the sound potentially becoming annoying on long road trips, are there any other mechanical or functional concerns regarding running all 4 exhausts open most or all the time?
I imagine there isn't but I want to make sure before I start growling up my neighborhood!
Last edited by RayintheGreatNW; Sep 15, 2017 at 01:54 PM.
Race Director
Joined: Dec 2013
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Sorry for the very basic question and I apologize if it has already been covered.
Aside from the sound potentially becoming annoying on long road trips, are there any other mechanical or functional concerns regarding running all 4 exhausts open most or all the time?
I imagine there isn't but I want to make sure before I start growling up my neighborhood!
Aside from the sound potentially becoming annoying on long road trips, are there any other mechanical or functional concerns regarding running all 4 exhausts open most or all the time?
I imagine there isn't but I want to make sure before I start growling up my neighborhood!
Short of the drone that your going to hear, no problem at all.
Hence when the gate valve is open, the exhaust is just sent through the shorter pipe through the muffler instead.
Racer
Joined: May 2017
Posts: 406
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From: Seattle WA
https://www.corvetteforum.com/forums...ally-work.html
No. I doubt it makes any extra HP either. Just a noise thing. I have mine open most of the time except for when I'm on the highway and trying to talk to my passenger, or for long road trips.
No. I doubt it makes any extra HP either. Just a noise thing. I have mine open most of the time except for when I'm on the highway and trying to talk to my passenger, or for long road trips.
Last edited by SivaSuryaKshatriya; Sep 15, 2017 at 01:59 PM.
Race Director
Joined: Apr 2000
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From: Texas
Sorry for the very basic question and I apologize if it has already been covered.
Aside from the sound potentially becoming annoying on long road trips, are there any other mechanical or functional concerns regarding running all 4 exhausts open most or all the time?
I imagine there isn't but I want to make sure before I start growling up my neighborhood!
Aside from the sound potentially becoming annoying on long road trips, are there any other mechanical or functional concerns regarding running all 4 exhausts open most or all the time?
I imagine there isn't but I want to make sure before I start growling up my neighborhood!
As an aside, when you run it open, barely any exhaust goes through the quiet side. Pretty much all through the inner tips.
Safety Car
Joined: Feb 2016
Posts: 4,456
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From: SC
https://www.corvetteforum.com/forums...ally-work.html
No. I doubt it makes any extra HP either. Just a noise thing. I have mine open most of the time except for when I'm on the highway and trying to talk to my passenger, or for long road trips.
No. I doubt it makes any extra HP either. Just a noise thing. I have mine open most of the time except for when I'm on the highway and trying to talk to my passenger, or for long road trips.
Melting Slicks
Joined: Aug 2005
Posts: 2,821
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From: Lincoln CA
NPP is rated at 6 more HP than non-NPP but keeping it open all the time won't make any more power than factory setup. However, I don't like the sound of the NPP opening and closing back down so I keep mine open most of the time. You don't need to spend any money to do it, just run a pair of wires to a switch. I only close mine for long highway runs, something I try to avoid like the plague.
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Le Mans Master
Joined: Oct 2014
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From: Atlanta GA
https://www.corvetteforum.com/forums...ally-work.html
No. I doubt it makes any extra HP either. Just a noise thing. I have mine open most of the time except for when I'm on the highway and trying to talk to my passenger, or for long road trips.
No. I doubt it makes any extra HP either. Just a noise thing. I have mine open most of the time except for when I'm on the highway and trying to talk to my passenger, or for long road trips.
Dave
Race Director
Joined: Jul 2005
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From: Central MO
I also have them open when the top is down, but also about half of the time when the top is up. It's amazing how much of an echo chamber the interior is with the top up. That said, it is still quieter than in a coupe.
Thread Starter
Intermediate
Joined: Aug 2017
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Thank You!
Thank your the awesome responses. MY M2W has been ordered and on its way!
However, I'm now super curious about the comment regarding increased HP...really? Wasn't expecting that. I'm not sure I understand how that would work.
However, I'm now super curious about the comment regarding increased HP...really? Wasn't expecting that. I'm not sure I understand how that would work.
Last edited by RayintheGreatNW; Sep 16, 2017 at 12:18 PM.
Pro
Joined: Aug 2014
Posts: 506
Likes: 92
From: Palestine...East Texas Piney Woods Tx
GS Convertible...Run mine open most of the time....I am curious if it affects gas mileage any to run them open most of the time. I cant tell any horsepower effect, but it sure sounds cool working it thru the gears on the M6 transmission.
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
There's not a butt-meter in the world that will feel the difference so don't get too excited.
Drifting
Joined: Mar 2013
Posts: 1,706
Likes: 539
From: Hampton VA
I pulled the fuse on mine but at a steady 50 or so the drone was terrible for me actually hurt my ears. Dont get me wrong I like noise my last vette had long tubes and a corsa exhaust and did not bither me at all even after a 17hour 1200 mile trip
Burning Brakes
Joined: Oct 2013
Posts: 993
Likes: 105
From: Dallas TX
St. Jude Donor '15
If I may piggy back on this thread with another question about NPP:
So you can let the system control the valves automatically, or you can install a mild to wild switch so you can control it 100%.
However, is there a 3rd option where you can let it be auto all the time and just over-ride when you want ?
So you can let the system control the valves automatically, or you can install a mild to wild switch so you can control it 100%.
However, is there a 3rd option where you can let it be auto all the time and just over-ride when you want ?
Drifting
Joined: Nov 2014
Posts: 1,318
Likes: 209
From: Lincoln Nebraska
If I may piggy back on this thread with another question about NPP:
So you can let the system control the valves automatically, or you can install a mild to wild switch so you can control it 100%.
However, is there a 3rd option where you can let it be auto all the time and just over-ride when you want ?
So you can let the system control the valves automatically, or you can install a mild to wild switch so you can control it 100%.
However, is there a 3rd option where you can let it be auto all the time and just over-ride when you want ?
Safety Car
Joined: Feb 2016
Posts: 4,456
Likes: 1,391
From: SC
NPP is rated at 6 more HP than non-NPP but keeping it open all the time won't make any more power than factory setup. However, I don't like the sound of the NPP opening and closing back down so I keep mine open most of the time. You don't need to spend any money to do it, just run a pair of wires to a switch. I only close mine for long highway runs, something I try to avoid like the plague.