NPP Exhaust - Function Check - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

4WDlifeform · 01-09-2019, 11:18 PM

2014 SS RS, 6-spd with NPP exhaust. Just installed headers, high flow CATs, and mild cam. Dang she sounds good!! But..

I am curious if my NPP flaps are working properly? I guess I am confused when the flaps should be closed, and when they should be open. The car is crazy loud now, and I fear that my neighbors are going to be angry when I leave in the mornings, and driving around town in parking lots, etc, the car is a bit of a beast. Which is cool and all, but at 10% throttle, I don't need to be making any statements.. So, yeah, I'm kinda saying its a bit loud at low throttle... Call me crazy!!

Anyway, I checked before that the fuse was still installed, and I recall that it was. I have a shimmer of a doubt I remember that correctly since I looked at the fuse box so long ago... Assuming that it is still installed...

Should the flaps be open during a warm idle? I always thought they should be closed? I have also read posts that the flaps only close when over 3500 RPM? What is true? How can I check that they are working properly?

I do not notice any difference in sound through the RPM range. It is loud, no matter what, and gets louder as RPM increases under load. I can say that I have never seen the flaps closed. But, I have never had anyone rev it up for me while I was watching. Just cold and warm idle, the flaps are always open.

Any thoughts would be greatly appreciated!

nty1234 · 01-09-2019, 11:50 PM

Flaps are always open at idle (cold or warm). I'm not sure of the exact rpms or throttle % but if you slowly take off you should be able to hear it close somewhere around 2-3k rpms. When you get on it they will open up. I have the NPP with cat delete pipes and I hear it so i'm sure you should be able to as-well.

Vegas Bound · 01-10-2019, 08:39 AM

See if ADM still has the remote system for NPP. I programmed mine to the HomeLink buttons. I can open and close at will. Every start up is open. Then I hit the button and it is closed.

DSX_Camaro · 01-10-2019, 08:42 AM

Yeah, one of the plug and play exhaust controllers might be good for you so you can run the NPP closed when you need it to be quiet.

4WDlifeform · 01-10-2019, 11:19 AM

Thanks for the comments. So it is true that the valves only close through a shrt RPM range?

Interested in the plug and play controller, I'll have to look more into that. I do not have the "engine sound management" on the menu, or any control at all (at least that I know of) from inside the cabin. So, I guess I am not sure if a controller would work on my car?

bkevind · 01-10-2019, 11:31 AM

I like the way it works as stock. Definitely louder with headers, but nice and quiet when cruising. Flaps open up and rips when you get on it.

Startup is loud for sure, I can see how if you're in a quiet little neighborhood and have an early start to the day you'd want it to be quieter.

DSX_Camaro · 01-10-2019, 01:16 PM

For ease: https://www.rickscamaros.com/camaro-...2010-2015.html

That's the specific controller I was thinking of. The other controllers allow open and closed but I don't think they have factory as an option? Or maybe it's open and factory and you can't force it closed. That 3 way controller has all 3 options though.

4WDlifeform · 01-10-2019, 08:18 PM

Quote:

Originally Posted by bkevind

I can see how if you're in a quiet little neighborhood and have an early start to the day you'd want it to be quieter.

"Quiet little neighborhood"! Haha Yeah, and I have a white picket fence and a golden retriever too..!!!!

Quote:

Originally Posted by DSX_Camaro

For ease: https://www.rickscamaros.com/camaro-...2010-2015.html

That's the specific controller I was thinking of. The other controllers allow open and closed but I don't think they have factory as an option? Or maybe it's open and factory and you can't force it closed. That 3 way controller has all 3 options though.

That's awesome! Thanks for sharing. I too wonder how the other "two mode" systems work.. Hopefully I'll have some time tomorrow to call around and get an exact answer. I am sure it exists here in the forum somewhere too.. I'll be searchin!

nty1234 · 01-10-2019, 11:57 PM

There is no need really to buy a controller. I wired mine up to a 3 way switch which I have installed in my center console, top position to force ground and keep them shut, middle position to keep them open and down position to retain stock function. I can't remember exactly where the post it but there is a whole writeup on it. I believe someone had actually asked a similar question not too long ago.

Level300 · 01-11-2019, 08:43 AM

I believe on start up they are open because there is no difference in sound when my flaps are set to always open. Then they shut but the damage has been done. They open at 3k.

There is one wire that you cut going to the trunk fuse block. You connect each end of that wire to a 3 way switch (on, off, on) and the other switch terminal to ground. I haven't done this yet but I do plan to.

A guy did a very nice write up on it complete with pictures. His method used 3 relays but did not require cutting any wires. His installation was simplified to just cutting one wire (and wiring to a switch). Do a search and you'll find it. It's a great write up.

JD555 · 01-11-2019, 11:42 AM

I bought the forza 3 way controller and it works well. I can keep it closed, keep it open or select the factory setting.

Reichler · 01-15-2019, 02:02 PM

Headers thru a fuse-pulled NPP is basically a muffler delete. I love it on mine but, yeah, it's loud.

JD555 · 01-15-2019, 02:43 PM

Quote:

Originally Posted by Reichler

Headers thru a fuse-pulled NPP is basically a muffler delete. I love it on mine but, yeah, it's loud.

Is it much louder than stock with the NPP closed or have you never tried it being the fuse is pulled. i would like to do headers but i get up early and like to close the flaps on startup.

01-09-2019, 11:18 PM	#1
4WDlifeform Drives: 2014 Camaro 1SS RS Join Date: Oct 2017 Location: Pittsburgh Posts: 75	NPP Exhaust - Function Check 2014 SS RS, 6-spd with NPP exhaust. Just installed headers, high flow CATs, and mild cam. Dang she sounds good!! But.. I am curious if my NPP flaps are working properly? I guess I am confused when the flaps should be closed, and when they should be open. The car is crazy loud now, and I fear that my neighbors are going to be angry when I leave in the mornings, and driving around town in parking lots, etc, the car is a bit of a beast. Which is cool and all, but at 10% throttle, I don't need to be making any statements.. So, yeah, I'm kinda saying its a bit loud at low throttle... Call me crazy!! Anyway, I checked before that the fuse was still installed, and I recall that it was. I have a shimmer of a doubt I remember that correctly since I looked at the fuse box so long ago... Assuming that it is still installed... Should the flaps be open during a warm idle? I always thought they should be closed? I have also read posts that the flaps only close when over 3500 RPM? What is true? How can I check that they are working properly? I do not notice any difference in sound through the RPM range. It is loud, no matter what, and gets louder as RPM increases under load. I can say that I have never seen the flaps closed. But, I have never had anyone rev it up for me while I was watching. Just cold and warm idle, the flaps are always open. Any thoughts would be greatly appreciated!

01-10-2019, 08:42 AM	#4
DSX_Camaro Drives: 2013 SW 2LT/RS LFX/AY6 Join Date: Feb 2013 Location: Orlando, FL Posts: 1,741	Yeah, one of the plug and play exhaust controllers might be good for you so you can run the NPP closed when you need it to be quiet. __________________ K&N CAI, 1LE Strut Tower Brace, Elite Engineering Catch Can and Clean Side Separator, Apex Scoop w/ Washer Relocation Kit, CTS Front Calipers and Rotors, JacFab Ported Intake Manifold, JacFab Intake Manifold Spacer, 80mm Overkill Throttle Body, SS Brake Lines, Ideal Garage Master Cylinder, Monster Twin Disc Clutch, NPP Retrofit w/ Magnaflow Resonated X, ARH Catless Downpipes, JRE Built 3.45 Diff, 1LE Axles, 1LE Hubs, Overkill Tuned, BMR Anti Wheel-hop Kit Stage I, ACS TL1 Hood Insert, ZL1 Spoiler

01-10-2019, 11:31 AM	#6
bkevind Drives: 2013 2SS RS 1LE Join Date: Aug 2016 Location: Austin Posts: 555 View My Garage	I like the way it works as stock. Definitely louder with headers, but nice and quiet when cruising. Flaps open up and rips when you get on it. Startup is loud for sure, I can see how if you're in a quiet little neighborhood and have an early start to the day you'd want it to be quieter. __________________ 468, Mishimoto rad + oil cooler, TSP LTH MCS 2WNR CTSV/ZL1 front calipers/rotors + G-Loc Forgestar CF-5 19x11

01-10-2019, 01:16 PM	#7
DSX_Camaro Drives: 2013 SW 2LT/RS LFX/AY6 Join Date: Feb 2013 Location: Orlando, FL Posts: 1,741	For ease: https://www.rickscamaros.com/camaro-...2010-2015.html That's the specific controller I was thinking of. The other controllers allow open and closed but I don't think they have factory as an option? Or maybe it's open and factory and you can't force it closed. That 3 way controller has all 3 options though. __________________ K&N CAI, 1LE Strut Tower Brace, Elite Engineering Catch Can and Clean Side Separator, Apex Scoop w/ Washer Relocation Kit, CTS Front Calipers and Rotors, JacFab Ported Intake Manifold, JacFab Intake Manifold Spacer, 80mm Overkill Throttle Body, SS Brake Lines, Ideal Garage Master Cylinder, Monster Twin Disc Clutch, NPP Retrofit w/ Magnaflow Resonated X, ARH Catless Downpipes, JRE Built 3.45 Diff, 1LE Axles, 1LE Hubs, Overkill Tuned, BMR Anti Wheel-hop Kit Stage I, ACS TL1 Hood Insert, ZL1 Spoiler

01-09-2019, 11:50 PM	#2
nty1234 Drives: 2015 2SS Summit White Join Date: Oct 2017 Location: Mitten State Posts: 161	Flaps are always open at idle (cold or warm). I'm not sure of the exact rpms or throttle % but if you slowly take off you should be able to hear it close somewhere around 2-3k rpms. When you get on it they will open up. I have the NPP with cat delete pipes and I hear it so i'm sure you should be able to as-well.

01-10-2019, 08:39 AM	#3
Vegas Bound Account Suspended Drives: 2013 Sparkly Red One Join Date: Dec 2018 Location: Hospitality State Posts: 2,558	See if ADM still has the remote system for NPP. I programmed mine to the HomeLink buttons. I can open and close at will. Every start up is open. Then I hit the button and it is closed.

01-10-2019, 11:19 AM	#5
4WDlifeform Drives: 2014 Camaro 1SS RS Join Date: Oct 2017 Location: Pittsburgh Posts: 75	Thanks for the comments. So it is true that the valves only close through a shrt RPM range? Interested in the plug and play controller, I'll have to look more into that. I do not have the "engine sound management" on the menu, or any control at all (at least that I know of) from inside the cabin. So, I guess I am not sure if a controller would work on my car?

01-10-2019, 11:57 PM	#9
nty1234 Drives: 2015 2SS Summit White Join Date: Oct 2017 Location: Mitten State Posts: 161	There is no need really to buy a controller. I wired mine up to a 3 way switch which I have installed in my center console, top position to force ground and keep them shut, middle position to keep them open and down position to retain stock function. I can't remember exactly where the post it but there is a whole writeup on it. I believe someone had actually asked a similar question not too long ago.

01-11-2019, 08:43 AM	#10
Level300 Drives: 2015 Black rs/ss/1le Join Date: Apr 2018 Location: PA Posts: 271	I believe on start up they are open because there is no difference in sound when my flaps are set to always open. Then they shut but the damage has been done. They open at 3k. There is one wire that you cut going to the trunk fuse block. You connect each end of that wire to a 3 way switch (on, off, on) and the other switch terminal to ground. I haven't done this yet but I do plan to. A guy did a very nice write up on it complete with pictures. His method used 3 relays but did not require cutting any wires. His installation was simplified to just cutting one wire (and wiring to a switch). Do a search and you'll find it. It's a great write up.

01-11-2019, 11:42 AM	#11
JD555 Drives: 2014 2SS RS, 6 sp man Join Date: Feb 2016 Location: Marlton, NJ Posts: 461	I bought the forza 3 way controller and it works well. I can keep it closed, keep it open or select the factory setting.

01-15-2019, 02:02 PM	#12
Reichler Drives: 2004 GTO & 2005 GTO Join Date: Mar 2014 Location: Lancaster, PA Posts: 303	Headers thru a fuse-pulled NPP is basically a muffler delete. I love it on mine but, yeah, it's loud.