[rmyers]

Does anyone know how much vacuum is required to close the actuators on 5th gen NPP exhaust?

The exhaust actuators on my 2012 Z are open all the time and do not close. The fuse is in place and is working.

I ran a vacuum hose from the connection of each NPP actuator to the inside of my car and placed a gauge on it so I could see if vacuum was being supplied while driving.

I tested each side separately, and each time the vacuum would range from 0 to -75 kpa.

So I know I have vacuum at each connection to the actuators, but they will not close. The actuators are NOT stuck, and can be closed by manually pressing the linkage in towards the canister.

Does anyone know what minimum vacuum required for normal operation should be?


The car was modified several years ago, and did receive a larger camshaft, heads, and other mods. About 660 hp at the wheels. But my recollection is that they still worked after the mods were made 11 years ago.

Any advice or technical information would be much appreciated.

Ron