NPP issue.... Ideas ??
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
NPP issue.... Ideas ??
Car has NPP mufflers and mild2wild control.
Went for a nice drive this weekend, mostly with flaps open. On the way back I noticed that with the flaps closed, one, or both are partially opening under mid to high throttle. They never did that before. They should stay closed when set to be.
Havent had much time to check yet. The only things I checked are that they are opening and closing as commanded at idle, and that they flaps seem to have normal resistance when pushing on them manually.
Any ideas of what to look for ??
Went for a nice drive this weekend, mostly with flaps open. On the way back I noticed that with the flaps closed, one, or both are partially opening under mid to high throttle. They never did that before. They should stay closed when set to be.
Havent had much time to check yet. The only things I checked are that they are opening and closing as commanded at idle, and that they flaps seem to have normal resistance when pushing on them manually.
Any ideas of what to look for ??
Instructor
Joined: Feb 2012
Posts: 223
Likes: 14
From: West Chester Ohio
I would suggest using a mighty vac and see how much vacuum it takes to actuate them. I just installed a set of Z06 mufflers and it takes about 10"/hg to fully actuate them. If they seem to operate normally with a mighty vac, I would think you have some sort of vacuum leak in your system.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
Originally Posted by EnviedC6
I would suggest using a mighty vac and see how much vacuum it takes to actuate them. I just installed a set of Z06 mufflers and it takes about 10"/hg to fully actuate them. If they seem to operate normally with a mighty vac, I would think you have some sort of vacuum leak in your system.
Instructor
Joined: Feb 2012
Posts: 223
Likes: 14
From: West Chester Ohio
I thought that the M2W switch only allowed you to override the factory system, allowing the flaps to be open when you want. I don't see how this can force them shut, otherwise. The factory system is something like over 3500 rpm and so much percent throttle. In the scenario you described, I would imagine it would let them open.
https://www.corvetteforum.com/forums...ally-work.html
https://www.corvetteforum.com/forums...ally-work.html
Last edited by EnviedC6; Oct 24, 2017 at 08:42 PM.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
Originally Posted by EnviedC6
I thought that the M2W switch only allowed you to override the factory system, allowing the flaps to be open when you want. I don't see how this can force them shut, otherwise. The factory system is something like over 3500 rpm and so much percent throttle. In the scenario you described, I would imagine it would let them open.
https://www.corvetteforum.com/forums...ally-work.html
https://www.corvetteforum.com/forums...ally-work.html
Instructor
Joined: Feb 2012
Posts: 223
Likes: 14
From: West Chester Ohio
Did you run an NPP in a box with a M2W? When I added mine, I just ran vacuum line from intake manifold straight to the mufflers. The M2W is for factory NPP systems I thought. If you are running an NPP in a box, than it is using a little vacuum pump to drive the actuators. That would mean the only possibility is a leak in that system and the pressure from exhaust just pushing the flaps open
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
Did you run an NPP in a box with a M2W? When I added mine, I just ran vacuum line from intake manifold straight to the mufflers. The M2W is for factory NPP systems I thought. If you are running an NPP in a box, than it is using a little vacuum pump to drive the actuators. That would mean the only possibility is a leak in that system and the pressure from exhaust just pushing the flaps open
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