NPP fuse pull trick/result
Tech Contributor
Joined: Jan 2006
Posts: 4,761
Likes: 240
From: Saint Louis MO
St. Jude Donor '14-'15
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
So just for kicks, I just went and actuated an NPP valve with my fingers.
It's a butterfly valve. There's a heavy return-to-open spring and the mechanical feel/damping of turning the servo/motor. So with no power there is effort to close it in winding up the spring and spinning the motor. Let it go and it opens only a little slowly; doesn't snap open. So my interpretation is that closed+cut power would allow them to open passively since it appears they want to open and stay open with no power. The motor works against/winds the return spring I think.
I think the switch would work and open the valves when power is cut.
It's a butterfly valve. There's a heavy return-to-open spring and the mechanical feel/damping of turning the servo/motor. So with no power there is effort to close it in winding up the spring and spinning the motor. Let it go and it opens only a little slowly; doesn't snap open. So my interpretation is that closed+cut power would allow them to open passively since it appears they want to open and stay open with no power. The motor works against/winds the return spring I think.
I think the switch would work and open the valves when power is cut.
I'm adding to the non Npp car. I think I like it! Even at worst
I can use a wired switch in the car.
I just want to open and close them like the C6!
Tech Contributor
Joined: Jan 2006
Posts: 4,761
Likes: 240
From: Saint Louis MO
St. Jude Donor '14-'15
Well absolute worst case you could replace the valves with aftermarket remote valves. I think the actuator is just controlled by a 12v hit.
Running directly to the valves may prove more fruitful than running to the fuse #41, which was an abysmal failure.
I'm just wiring directly to fuse 41 now, though you'll need to go from the cutouts. Let us know how they fare with that - I know they can make it work, though.
Running directly to the valves may prove more fruitful than running to the fuse #41, which was an abysmal failure.
I'm just wiring directly to fuse 41 now, though you'll need to go from the cutouts. Let us know how they fare with that - I know they can make it work, though.
Le Mans Master
Joined: Oct 2004
Posts: 8,615
Likes: 60
From: Haymarket Virginia
This sounding like I can use a mild to wild to switch the valves closed/open on the NPP. Just have to buy two valve motors!
I'm adding to the non Npp car. I think I like it! Even at worst
I can use a wired switch in the car.
I just want to open and close them like the C6!
I'm adding to the non Npp car. I think I like it! Even at worst
I can use a wired switch in the car.
I just want to open and close them like the C6!
Racer
Joined: Mar 2006
Posts: 304
Likes: 1
From: Ridley Park PA
I know I am chiming in on this late but I have the M7 z51 but I put BB bullet exhaust on it, does this issue effect the BB as well or is it just a NPP sound. As I notice the BB had valves on the top and is suppose to sound the same in even in 4cyl. However, I notice a bog down sound when it goes into 4....
I also think it should be louder when I start the car like a all open scream
I also think it should be louder when I start the car like a all open scream
Tech Contributor
Joined: Jan 2006
Posts: 4,761
Likes: 240
From: Saint Louis MO
St. Jude Donor '14-'15
If you're talking about the B&B Bullet Exhaust with the two valves, those are only for the 4cyl DoD mode.
You can not use this method unless you want to deactivate those valves from adjusting during 4cyl mode. You will most likely (as seen here early in the thread) get a CEL from this, as well.
If you have the B&B set with 4 valves, then yes, this thread does also pertain to you.
You can not use this method unless you want to deactivate those valves from adjusting during 4cyl mode. You will most likely (as seen here early in the thread) get a CEL from this, as well.
If you have the B&B set with 4 valves, then yes, this thread does also pertain to you.
Racer
Joined: Mar 2006
Posts: 304
Likes: 1
From: Ridley Park PA
If you're talking about the B&B Bullet Exhaust with the two valves, those are only for the 4cyl DoD mode.
You can not use this method unless you want to deactivate those valves from adjusting during 4cyl mode. You will most likely (as seen here early in the thread) get a CEL from this, as well.
If you have the B&B set with 4 valves, then yes, this thread does also pertain to you.
You can not use this method unless you want to deactivate those valves from adjusting during 4cyl mode. You will most likely (as seen here early in the thread) get a CEL from this, as well.
If you have the B&B set with 4 valves, then yes, this thread does also pertain to you.
Thanks Theta,
Yes I have the bullets with only two, I was just checking that this would not apply. I almost feel the BB Bullets are a tad quieter on the c7 then when i had them on my c6. thats why I was asking.
Racer
Joined: Sep 2004
Posts: 493
Likes: 109
From: Central California
I don't know if I'm understanding all this correctly or if something is wrong with my manual non -z51. I pulled out fuse 41. No CEL, but I can BARELY detect any difference in sound. My wife was in the passenger and we drove about 30 miles mixed driving and she can't tell the difference. It's a bit louder when I stomp on the gas. My engine management setting is set to "off". What I'm I missing here?
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Tech Contributor
Joined: Jan 2006
Posts: 4,761
Likes: 240
From: Saint Louis MO
St. Jude Donor '14-'15
The only thing you'll gain from this vs. engine sound management off is the lack of 1700rpm tip-in, and the sport mode tip-in delay.
This just leaves the valves open full-time.
This just leaves the valves open full-time.
Racer
Joined: Sep 2013
Posts: 302
Likes: 3
From: Sarasota Florida
St Jude Donor '14
I pulled fuse 41 on mine. I'll drive around for a while and see how it does. My car is very noticable for the vlaves closing in 4th until about 1700rpm's since i have offroad pipes. I'll report back if i see any CEL's.
Racer
Joined: Sep 2013
Posts: 302
Likes: 3
From: Sarasota Florida
St Jude Donor '14
I pulled fuse 41 and I saw (heard) no difference. My car still gets quite in 4th up till 1700 rpm's then I can noticeably hear it get louder as if valves are opening up. I got no CEL's but I heard no change in the way my car sounded going thru the gears. On my car it's very noticeable due to the off road exhaust on my car. My car is pretty loud just going down the road.
Tech Contributor
Joined: Jan 2006
Posts: 4,761
Likes: 240
From: Saint Louis MO
St. Jude Donor '14-'15
Pulled 41 in prep for installing my switch (which I will install today) and can confirm that it removes the tip-in delay and sport delay.
Very happy with that. The switch location is awesome but I need to make sure of a few things first.
Very happy with that. The switch location is awesome but I need to make sure of a few things first.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,425
Likes: 238
From: Macomb MI
Theta, thanks for your continued work on this!
Took mine out on some unnecessary errands after a week without. Love the 100% open. I did chuckle a bit since all of us are addicted to the sound so much, all this effort is to solve the 1% problem. We can't take ONLY 99% open. This is seriously a first-world problem.
QUESTION: Do any A6 NPP folks notice the 1700RPM tip-in/sport mode delays?
I'm wondering since it seems it's us M7 folks that notice it so much. Which makes me also wonder if the A6 is either just less noticeable since it wouldn't tend to lug on tip-in, or if it's programmed differently.
Safety Car
Joined: Dec 2003
Posts: 4,240
Likes: 1,879
From: USA
Just found this thread and in anticipation of getting my C7 with the NPP exhaust in a few weeks wanted to ask a couple quick questions. First, is the 41 fuse the only one that should be pulled if you're trying to get the loudest overall sound from the exhaust at all RPMs? Also, if you pull fuse 41 what setting should you use for the engine management....would you set it to On or Off? Finally, does it make any difference if the car is in Sport or Track mode?
I've had Borla Stingers on my C5 for years and honestly I'm looking forward to a car that's a little quieter and doesn't have the horrible drone on the inside, but I still want it to sound as mean as possible at all RPMs so hopefully pulling the 41 fuse does the trick.
I've had Borla Stingers on my C5 for years and honestly I'm looking forward to a car that's a little quieter and doesn't have the horrible drone on the inside, but I still want it to sound as mean as possible at all RPMs so hopefully pulling the 41 fuse does the trick.
Tech Contributor
Joined: Jan 2006
Posts: 4,761
Likes: 240
From: Saint Louis MO
St. Jude Donor '14-'15
Yes, only fuse 41. Engine management setting I use is OFF. No difference in any mode, as the valves are now open full-time (even in Eco mode).
You'll enjoy the lack of drone but huge sound (especially with headers - it's deafening). At 1500RPM / 70mph, it's completely smooth and quiet.
You'll enjoy the lack of drone but huge sound (especially with headers - it's deafening). At 1500RPM / 70mph, it's completely smooth and quiet.
Safety Car
Joined: Dec 2003
Posts: 4,240
Likes: 1,879
From: USA
Yes, only fuse 41. Engine management setting I use is OFF. No difference in any mode, as the valves are now open full-time (even in Eco mode).
You'll enjoy the lack of drone but huge sound (especially with headers - it's deafening). At 1500RPM / 70mph, it's completely smooth and quiet.
You'll enjoy the lack of drone but huge sound (especially with headers - it's deafening). At 1500RPM / 70mph, it's completely smooth and quiet.
Nobody has experienced a CEL by just pulling that fuse, right?
By the way, I see you're in STL. I live in Carbondale which is just about a 100 miles away. Go Cardinals!!!
