Npp exhaust question - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

CJ27 · 05-04-2021, 12:22 PM

The fuse is there and good and I have vacuum coming off the engine going down behind the engine. No vaccum at the actuator valves themselves. My question, is there anything a tuner could have done in the tune that would keep the valves from closing? I know it's not a dramatic difference in sound decibels but I would like them closing again.

RobZL1 · 05-04-2021, 02:03 PM

Nothing in the tune on a 5th gen.

CJ27 · 05-04-2021, 02:28 PM

Quote:

Originally Posted by RobZL1

Nothing in the tune on a 5th gen.

Ok ty.

CJ27 · 05-04-2021, 04:46 PM

Quote:

Originally Posted by RobZL1

Nothing in the tune on a 5th gen.

Messed around with it. Has vacuum and the fuse is good but it never receives any voltage to the solenoid to send vacuum to the actuators to close the valves. Any ideas?

ZMEnow · 05-04-2021, 09:29 PM

Quote:

Originally Posted by CJ27

Messed around with it. Has vacuum and the fuse is good but it never receives any voltage to the solenoid to send vacuum to the actuators to close the valves. Any ideas?

Are you a second or third owner, check that they never installed a mild to wild switch set up.

CJ27 · 05-04-2021, 10:33 PM

Quote:

Originally Posted by ZMEnow

Are you a second or third owner, check that they never installed a mild to wild switch set up.

Second owner and it use to work fine. That's why I was thinking my previous tuner could have turned it off. Sense that's not the issue I'll have to track down all the wiring it looks like.

CJ27 · 05-05-2021, 12:57 AM

Working again thanks everyone. Was thinking it should close at idle and apparently I was remembering this incorrectly.... my bad, it is working as designed.

Genob4c · 05-19-2021, 06:26 AM

Now, I'm confused. I thought they were closed at idle to force the exhaust into the muffler to keep it quieter until you put the hammer down. Am I wrong?

Dega Man · 05-19-2021, 07:16 AM

The exhaust valve is only closed between around 2100 rpm's to around 3000 rpm's otherwise it is open.

12oclockshadow · 05-19-2021, 11:18 AM

Quote:

Originally Posted by Dega Man

The exhaust valve is only closed between around 2100 rpm's to around 3000 rpm's otherwise it is open.

Is this true. So maybe mine does work. Ive been thinking it sb closed at idle. Hmmm i need to just drive mine more to see. I have a m2w thats need to be installes but the car npp wasn't working like stock to begin with.

larry_g · 05-19-2021, 11:40 AM

Quote:

Originally Posted by 12oclockshadow

Is this true. So maybe mine does work. Ive been thinking it sb closed at idle. Hmmm i need to just drive mine more to see. I have a m2w thats need to be installes but the car npp wasn't working like stock to begin with.

True, NPP is open at idle. That's why I put in a three way switch so I can go full closed at startup early in the morning.

12oclockshadow · 05-19-2021, 11:42 AM

Quote:

Originally Posted by larry_g

True, NPP is open at idle. That's why I put in a three way switch so I can go full closed at startup early in the morning.

How difficult is this over the m2w install?

RobZL1 · 05-19-2021, 12:00 PM

Quote:

Originally Posted by larry_g

True, NPP is open at idle. That's why I put in a three way switch so I can go full closed at startup early in the morning.

I do the same. Helps immensely with the initial roar.

larry_g · 05-19-2021, 12:19 PM

Quote:

Originally Posted by 12oclockshadow

How difficult is this over the m2w install?

I thought it was pretty easy. There was a good writeup here with a wiring diagram.

Basically you break the line from the FPCM to the fuse block and run it through a three position switch (probably similar to M2W.

One position is open, same as fuse pull. One position is closed, same as normal operation. And one position goes to ground, full closed.

Sent from my Pixel 5 using Tapatalk

05-04-2021, 12:22 PM	#1
CJ27 Drives: Chevrolet camaro zl1 Join Date: May 2019 Location: Tajas Posts: 104	Npp exhaust question The fuse is there and good and I have vacuum coming off the engine going down behind the engine. No vaccum at the actuator valves themselves. My question, is there anything a tuner could have done in the tune that would keep the valves from closing? I know it's not a dramatic difference in sound decibels but I would like them closing again. __________________ 2014 Sliver ZL1. Built engine, Stage 1 Frankenstein heads, Magnuson, SW long tubes, AFCO H/E, She Gone cam, flex fuel sensor, meth injection. 820rwhp e85.

05-04-2021, 02:03 PM	#2
RobZL1 fo'shizZL1 Drives: 2017 ZL1 Join Date: Aug 2017 Location: ATL Posts: 1,281	Nothing in the tune on a 5th gen. __________________ 2017 ZL1 M6 Black \| Maggie 2650 // 103TB // Big Gulp Past Rides- 2014 ZL1 M6 Red Hot \| Tons of mods 2004 CTS-V M6 Silver \| Many mods 1995 Corvette M6 Torch Red \| A few more mods 1992 Camaro M5 White \| A few mods

05-05-2021, 12:57 AM	#7
CJ27 Drives: Chevrolet camaro zl1 Join Date: May 2019 Location: Tajas Posts: 104	Working again thanks everyone. Was thinking it should close at idle and apparently I was remembering this incorrectly.... my bad, it is working as designed. __________________ 2014 Sliver ZL1. Built engine, Stage 1 Frankenstein heads, Magnuson, SW long tubes, AFCO H/E, She Gone cam, flex fuel sensor, meth injection. 820rwhp e85.

05-19-2021, 06:26 AM	#8
Genob4c Drives: 2015 Camaro Z/28 Join Date: May 2011 Location: Winchester, KY Posts: 342	Now, I'm confused. I thought they were closed at idle to force the exhaust into the muffler to keep it quieter until you put the hammer down. Am I wrong? __________________ Now: 2015 Z/28 Former: 2013 ZL1 Vert – Crystal Red 1978 Corvette Pace Car 1969 Pace Car 1969 Z/28 – Cortez Silver, 1974 LT/Z28 Blue 1974 Z28 Dark Green , 1976 Camaro Type LT – Black 1980 Z28 – Charcoal, 1981 Z28 – Dark Blue 1981 Z28 – Claret, 1982 Pace Car 1986 IROC – Red, 1993 Z28 – Red 1996 Z28 vert, 1998 Z28 Dk Blue 2002 B4C 2004 Vette – LeMans Blue 2008 Vette - CRT 2011 Camaro Pace Car

05-19-2021, 07:16 AM	#9
Dega Man Drives: ZL1 Join Date: Oct 2012 Location: Talladega Posts: 631	The exhaust valve is only closed between around 2100 rpm's to around 3000 rpm's otherwise it is open.