NPP mufflers and Boost?
Thread Starter
Pro
Joined: Mar 2012
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From: Carol Stream IL
NPP mufflers and Boost?
Hi,
I was planning to install 2008 NPP mufflers from an LS3 on my 2005 base C6 that wasn't equipped with NPP mufflers. It occurred the me that if the vacuum solenoids are actuated by engine vacuum, then on a forced induction engine, such as mine, they will also see boost under hard acceleration. I'd like to know if the boost has caused any problems with the actuators, like causing them to fail. Please tell me how many miles you've been using your NPP mufflers with a supercharger, how much boost you're running and if it's caused any failures or other issues.
I was planning to install 2008 NPP mufflers from an LS3 on my 2005 base C6 that wasn't equipped with NPP mufflers. It occurred the me that if the vacuum solenoids are actuated by engine vacuum, then on a forced induction engine, such as mine, they will also see boost under hard acceleration. I'd like to know if the boost has caused any problems with the actuators, like causing them to fail. Please tell me how many miles you've been using your NPP mufflers with a supercharger, how much boost you're running and if it's caused any failures or other issues.
Melting Slicks
Joined: Feb 2013
Posts: 2,034
Likes: 111
i have a z06 setup retrofitted onto my procharged 2005 corvette also, been at 850-860whp of whatever for a bit and no problems so far.
a buddy of mine has had his 2008 c6 boosted with stock NPP mufflers for like 50k miles without issues.
seems like lots of guys run these without boost and i haven't seen any fail
a buddy of mine has had his 2008 c6 boosted with stock NPP mufflers for like 50k miles without issues.
seems like lots of guys run these without boost and i haven't seen any fail
Thread Starter
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Joined: Mar 2012
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From: Carol Stream IL
Thanks for the input. Looks like this project is a go. I think the Z06 NPP actuators are the same as the LS3 actuators, so I think it should be reliable for the most part.
How are you tapping into engine vacuum and will the hose pop off under boost? I assume a hose clamp is needed.
How are you tapping into engine vacuum and will the hose pop off under boost? I assume a hose clamp is needed.
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
No problems here. ECS, 10 psi or more.. if you're that worried about it add a 1 way valve so they never see boost.
All depends on how you want them to operate and how you're going to control them
I added a tee to the hose that connects to the blow off valve on the intercooler. Then just ran a vacuum hose through the driver side rocker panel, through rear wheel well. Add a splitter there to split it down to two smaller hoses and connected those to NPP valves.
All depends on how you want them to operate and how you're going to control them
I added a tee to the hose that connects to the blow off valve on the intercooler. Then just ran a vacuum hose through the driver side rocker panel, through rear wheel well. Add a splitter there to split it down to two smaller hoses and connected those to NPP valves.
Last edited by schpenxel; Jan 21, 2016 at 04:49 PM.
Thread Starter
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Joined: Mar 2012
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From: Carol Stream IL
No problems here. ECS, 10 psi or more.. if you're that worried about it add a 1 way valve so they never see boost.
All depends on how you want them to operate and how you're going to control them
I added a tee to the hose that connects to the blow off valve on the intercooler. Then just ran a vacuum hose through the driver side rocker panel, through rear wheel well. Add a splitter there to split it down to two smaller hoses and connected those to NPP valves.
All depends on how you want them to operate and how you're going to control them
I added a tee to the hose that connects to the blow off valve on the intercooler. Then just ran a vacuum hose through the driver side rocker panel, through rear wheel well. Add a splitter there to split it down to two smaller hoses and connected those to NPP valves.
Also, I'm not that concerned about damaging the solenoids with the positive feedback I've been seeing here. I just wanted to make sure wasn't going to go down a proven path to failure. Cheers.
Melting Slicks
Joined: Feb 2013
Posts: 2,034
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i just run mine off the "NPP In a box" kit so it's 100% manual turn on and off for my car and then i just double sided taped mine to my methanol controller which sits right by my right knee. tapped for vaccum by just t'ing into the brake booster line which took about 1 minute
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Thread Starter
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Joined: Mar 2012
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From: Carol Stream IL
i just run mine off the "NPP In a box" kit so it's 100% manual turn on and off for my car and then i just double sided taped mine to my methanol controller which sits right by my right knee. tapped for vaccum by just t'ing into the brake booster line which took about 1 minute
I considered tapping into the brake booster line as well but was a little concerned about diminished brake performance since I sometimes do HPDEs. Im probably just overly cautious.
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
Yeah it won't hurt anything. On the ECS kit they splice into the brake booster hose to connect up the hobbs switch for the boost-a-pump and blow off/bypass valve.
The plastic connector that the brake vacuum hose connects to on on brake booster has a one way valve built into it, so it will store whatever the highest vacuum it sees is
The plastic connector that the brake vacuum hose connects to on on brake booster has a one way valve built into it, so it will store whatever the highest vacuum it sees is
Le Mans Master
Joined: Jan 2009
Posts: 5,656
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From: ocean springs mississippi
I did the (npp in a box) kit on mine. Was working great til we Dynoed it (blower)....now won't close the valves....can't seem to find the issue. Thoughts?
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From: Carol Stream IL
The dyno procedure I believe requires an 02 sensor to be inserted in the exhaust. So they need to deactivate the actuator so the exhaust gases only come out one muffler outlet on each muffler. The probably disconnected the vacuum line to do this and They probably didn't reconnect the vacuum source to the solenoids when they were done.
Melting Slicks
Joined: Oct 2007
Posts: 2,569
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Just make sure that if you are using an aftermarket controller instead of a factory equipped NPP that you open the valves before going into boost. They are not designed to be closed except for under 3000 rpm causing and idle.
Last edited by lt1z; Jan 23, 2016 at 05:24 PM.
Le Mans Master
Joined: Jan 2009
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From: ocean springs mississippi
It will only be closed for cruising with the wife (she doesn't like hand acceleration /horseplay )....open all other times
Safety Car
Joined: Nov 2007
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From: Bay Area CA
Hi,
I was planning to install 2008 NPP mufflers from an LS3 on my 2005 base C6 that wasn't equipped with NPP mufflers. It occurred the me that if the vacuum solenoids are actuated by engine vacuum, then on a forced induction engine, such as mine, they will also see boost under hard acceleration. I'd like to know if the boost has caused any problems with the actuators, like causing them to fail. Please tell me how many miles you've been using your NPP mufflers with a supercharger, how much boost you're running and if it's caused any failures or other issues.
I was planning to install 2008 NPP mufflers from an LS3 on my 2005 base C6 that wasn't equipped with NPP mufflers. It occurred the me that if the vacuum solenoids are actuated by engine vacuum, then on a forced induction engine, such as mine, they will also see boost under hard acceleration. I'd like to know if the boost has caused any problems with the actuators, like causing them to fail. Please tell me how many miles you've been using your NPP mufflers with a supercharger, how much boost you're running and if it's caused any failures or other issues.
Last edited by Mike's LS3; Jan 23, 2016 at 08:14 PM.
Thread Starter
Pro
Joined: Mar 2012
Posts: 572
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From: Carol Stream IL
I don't think the mufflers will give a darn whether the valves are closed or not. I think the only failure susceptibility would be the actuators and everyone on here seems to think there is no or very little issue/concern. I'm willing to give it a shot.
