NPP controller questions
Thread Starter
Drifting
Joined: Nov 2009
Posts: 1,385
Likes: 102
NPP controller questions
So guys I'm converting my car from stock exhaust to NPP. I would like to somehow utilize the system so that it opens at rpm like the factory does as opposed to having one or the other with a fob. I know sunset used to make a commander that could do that, is there any current controller that allows an rpm/vacuum function to operate the mufflers or are we stuck with just the npp in a box option? If so has anyone just run vacuum straight off the motor? I would think at a certain throttle input the vacuume would become non existent and the blades would open anyway.
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
You can just install the factory NPP controller. The NPP valves are controlled by a separate module, NOT the engine control module or body control module.. and the good news is it's fairly cheap. $75 or so. Then the vacuum solenoid you need is about $75 also.
Basically the NPP control module connects to one of the CAN buses, connects to power, and connects to a solenoid that turns the solenoid on/off that connects the flaps to vacuum. It's basically a standalone computer that decides when to open/close the NPP flaps. It's not bad to install.
Here are some pictures and a wiring diagram from when I installed mine. It wasn't too bad to install.
https://www.corvetteforum.com/forums...post1591003860
Basically the NPP control module connects to one of the CAN buses, connects to power, and connects to a solenoid that turns the solenoid on/off that connects the flaps to vacuum. It's basically a standalone computer that decides when to open/close the NPP flaps. It's not bad to install.
Here are some pictures and a wiring diagram from when I installed mine. It wasn't too bad to install.
https://www.corvetteforum.com/forums...post1591003860
Thread Starter
Drifting
Joined: Nov 2009
Posts: 1,385
Likes: 102
Thanks man, do you happen to have a part number for the control module there I'm having trouble finding it. However I did manage to find the vacuum solenoid. Also i dont have dash logic so would I still wire it to the serial bus plug via an "orange" wire like you have and they wire everything else to hot/ground as normal? Would it still be controlled by the mirror swtich then or would it just function as a normal npp car.
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
Yes it needs to be wired to serial bus regardless.. that's how it gets info about when it send the "open" or "closed" signal. It reads RPM, throttle, etc. from the serial bus data.
This is the one I'm using.. there are a few different versions that are setup to open at different times (I'm not sure the exact differences). If you search for this part number on one of the GM parts websites you can probably find the # for the "regular" one
Without dash logic the mirror switch won't do anything regarding NPP
Did you find the part number for the connectors on the NPP controller? I think they're in that thread I linked to.. if not they are in another one I can dig up.
This is the one I'm using.. there are a few different versions that are setup to open at different times (I'm not sure the exact differences). If you search for this part number on one of the GM parts websites you can probably find the # for the "regular" one
Without dash logic the mirror switch won't do anything regarding NPP
Did you find the part number for the connectors on the NPP controller? I think they're in that thread I linked to.. if not they are in another one I can dig up.
Thread Starter
Drifting
Joined: Nov 2009
Posts: 1,385
Likes: 102
It's just the normal vacuum solenoid correct? Comes with a few lines and mounts near the back of the manifold? If so then yes and ok so that will get wired into the bus, there's nothing in the tune that needs to be turned on though so it reads rpm and gives power? In other words it's active even though the car didn't come with npp
Race Director
Joined: May 2004
Posts: 16,667
Likes: 1,209
From: Raleigh, NC
St. Jude Donor '15
No tune changes since it's own little computer and is totally separate from the ECM/BCM. Just plug it in and it should work.
Connectors for controller I figured out and posted here:
https://www.corvetteforum.com/forums...post1590715392
Connector for solenoid is a fuel injector connector basically.. got mine here:
The solenoid is a weird one the way it works, so I used the real GM one. It comes with some hoses, etc. I just pulled those off and ran my own lines.
Solenoid part number is 25794609
Connectors for controller I figured out and posted here:
https://www.corvetteforum.com/forums...post1590715392
Connector for solenoid is a fuel injector connector basically.. got mine here:
The solenoid is a weird one the way it works, so I used the real GM one. It comes with some hoses, etc. I just pulled those off and ran my own lines.
Solenoid part number is 25794609
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