npp exh - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

ib422goon · 11-09-2022, 09:42 AM

How does NPP exh work on a 2015?

NOT A 45 · 11-09-2022, 09:46 AM

Exhaust Tail Pipe Flow Control System Description and Operation
The exhaust tailpipe flow control system is used to tune the exhaust note for high performance vehicles. The vehicle is equipped with two tailpipe exhaust valves – a left one and a right one. Each exhaust tailpipe valve is installed in the low restriction exhaust path of a dual outlet muffler, near the exhaust tip. When a tailpipe exhaust valve is open, the low restriction exhaust path is exposed to atmosphere, and the exhaust note becomes more characteristically high performance.

An output circuit from the chassis control module is used to operate a relay-controlled solenoid valve that regulates vacuum to the left and right exhaust tailpipe valves. When the exhaust flow control valve relay is energized (turned on), the exhaust flow control valve solenoid opens and applies vacuum to the exhaust tailpipe valves, causing them to close. When the exhaust flow control valve relay is de-energized (turned off), the exhaust flow control valve solenoid closes, which isolates the exhaust tailpipe valves from vacuum and causes them to open.

To provide a more aggressive exhaust note when the vehicle is started, the exhaust tailpipe valves are opened during an engine cranking event. Once the engine is running, accelerator pedal position, transmission gear and engine speed are used to determine the commanded state (open or closed) of the exhaust tailpipe valves.

ib422goon · 11-09-2022, 11:23 AM

How is the exh valve opened and closed?

1JEWLDSSRS · 11-09-2022, 11:37 AM

Quote:

Originally Posted by ib422goon

How is the exh valve opened and closed?

An output circuit from the chassis control module is used to operate a relay-controlled solenoid valve that regulates vacuum to the left and right exhaust tailpipe valves. When the exhaust flow control valve relay is energized (turned on), the exhaust flow control valve solenoid opens and applies vacuum to the exhaust tailpipe valves, causing them to close. When the exhaust flow control valve relay is de-energized (turned off), the exhaust flow control valve solenoid closes, which isolates the exhaust tailpipe valves from vacuum and causes them to open.

As 45 stated above!!

jokrz187 · 11-09-2022, 12:19 PM

so basically it is automated and around a certain RPMs the valves open/close. i don't remember what the RPM level is, i want to say between 2-3. i have installed my own switch that is three way. i can put it on factory/open all the time/ closed all the time. its been a year since i did mine.

here is the thread for that if interested:
https://www.camaro5.com/forums/showthread.php?t=318683

CamaroGuy61 · 11-09-2022, 04:05 PM

It opens at 3000 rpms. I have a 2015 1LE with NPP.

SS376 · 11-09-2022, 05:07 PM

Just pull the fuse and it won't work at all! Stays open all the time and always sounds good.

CamaroDreams76 · 11-10-2022, 10:26 AM

Or do the Forza exhaust controller so it can work like stock, always open or always closed.

FasNuf · 11-10-2022, 09:13 PM

Quote:

Originally Posted by CamaroDreams76

Or do the Forza exhaust controller so it can work like stock, always open or always closed.

It's way less expensive and more effective to just use a switch.

CamaroDreams76 · 11-11-2022, 07:42 AM

Quote:

Originally Posted by FasNuf

It's way less expensive and more effective to just use a switch.

It sure is but that's an alternative for someone that doesn't want to wire in a switch.

I like my little fob and Forza has excellent customer service.

NOT A 45 · 11-11-2022, 08:36 AM

I have long tubes, and high flo's w/npp. I pulled the fuse and the sound is incredible with absolutely no drone on the highway. Don't understand why anyone would want to switch it back and forth unless perhaps you have AFM. That sound in 4 cyl mode is disgusting!

FasNuf · 11-11-2022, 10:28 AM

Quote:

Originally Posted by CamaroDreams76

It sure is but that's an alternative for someone that doesn't want to wire in a switch.

I like my little fob and Forza has excellent customer service.

True, everyone has their wiring comfort zone. It was just an option.

FasNuf · 11-11-2022, 10:30 AM

Quote:

Originally Posted by NOT A 45

I have long tubes, and high flo's w/npp. I pulled the fuse and the sound is incredible with absolutely no drone on the highway. Don't understand why anyone would want to switch it back and forth unless perhaps you have AFM. That sound in 4 cyl mode is disgusting!

I was glad one afternoon that I had the ability to switch to closed as a cop pulled up next to me at a light. Nice and quiet as I pulled away from him.

NOT A 45 · 11-11-2022, 10:55 AM

Quote:

Originally Posted by FasNuf

I was glad one afternoon that I had the ability to switch to closed as a cop pulled up next to me at a light. Nice and quiet as I pulled away from him.

While waiting on the wife to come out of the grocery store I had one come up to me and want to measure my window tint. I humored him...were allowed 35% here in Maryland. When he finished, he came back to me with a inspection ticket ordering me to have the tint removed.

I had to inform him that first off I watched him measure and he didn't calibrate the device properly and his reading isn't accurate. And secondly that if he'd like I can sign off on the ticket and hand it back to him since I'm a state inspector and have the authority to certify tint. He didn't say another word, just took the ticket went back to his car and left.

Definitely one of my better dealings with the sheriff's department! Oh and my tint is around 17%......20% film and another 3% that's made into the glass. lol

11-09-2022, 09:42 AM	#1
ib422goon Drives: 2015 rs/ss Join Date: Jan 2014 Location: Grants Pass Or. Posts: 19	npp exh How does NPP exh work on a 2015?

11-09-2022, 12:19 PM	#5
jokrz187 Drives: 2015 1SS Join Date: Jun 2017 Location: Stafford, VA Posts: 402 View My Garage	so basically it is automated and around a certain RPMs the valves open/close. i don't remember what the RPM level is, i want to say between 2-3. i have installed my own switch that is three way. i can put it on factory/open all the time/ closed all the time. its been a year since i did mine. here is the thread for that if interested: https://www.camaro5.com/forums/showthread.php?t=318683 __________________ ------------------------------------------------------- Custom TSP Stage 2 Cam/GPI intake Ported Rod Mod /VARARAM CAI/Mishimoto Catch Can/1 LE front & rear sway bars/ engine cover/fuse box custom painted, strut tower brace, Texas Speed LT, Hi Flo Cats, Magnum Tru-X pipe, NGK Spark Plugs, PCM Spark Plug Wire, Painted Calipers, CF Spoiler w/wicker bill.

11-10-2022, 10:26 AM	#8
CamaroDreams76 Tri-County Camaro SWFL Drives: 2013 IOM 2SS/RS/1LE Join Date: Apr 2013 Location: South West FL Posts: 3,103 View My Garage	Or do the Forza exhaust controller so it can work like stock, always open or always closed. __________________ Just bolt ons........ https://www.camaro5.com/forums/showthread.php?t=343023

11-09-2022, 09:46 AM	#2
NOT A 45 Drives: 13 CAMARO 2SS LS3-04 SILVERADO LS3 Join Date: Dec 2021 Location: SOUTHERN MARYLAND Posts: 802	Exhaust Tail Pipe Flow Control System Description and Operation The exhaust tailpipe flow control system is used to tune the exhaust note for high performance vehicles. The vehicle is equipped with two tailpipe exhaust valves – a left one and a right one. Each exhaust tailpipe valve is installed in the low restriction exhaust path of a dual outlet muffler, near the exhaust tip. When a tailpipe exhaust valve is open, the low restriction exhaust path is exposed to atmosphere, and the exhaust note becomes more characteristically high performance. An output circuit from the chassis control module is used to operate a relay-controlled solenoid valve that regulates vacuum to the left and right exhaust tailpipe valves. When the exhaust flow control valve relay is energized (turned on), the exhaust flow control valve solenoid opens and applies vacuum to the exhaust tailpipe valves, causing them to close. When the exhaust flow control valve relay is de-energized (turned off), the exhaust flow control valve solenoid closes, which isolates the exhaust tailpipe valves from vacuum and causes them to open. To provide a more aggressive exhaust note when the vehicle is started, the exhaust tailpipe valves are opened during an engine cranking event. Once the engine is running, accelerator pedal position, transmission gear and engine speed are used to determine the commanded state (open or closed) of the exhaust tailpipe valves.

11-09-2022, 11:23 AM	#3
ib422goon Drives: 2015 rs/ss Join Date: Jan 2014 Location: Grants Pass Or. Posts: 19	How is the exh valve opened and closed?

11-09-2022, 04:05 PM	#6
CamaroGuy61 Drives: 2015 Camaro 2ss 1LE Join Date: Sep 2022 Location: South Carolina Posts: 44	It opens at 3000 rpms. I have a 2015 1LE with NPP.

11-09-2022, 05:07 PM	#7
SS376 Drives: 2013 1SS LS3 Join Date: Feb 2014 Location: Massachusetts Posts: 808	Just pull the fuse and it won't work at all! Stays open all the time and always sounds good.

11-11-2022, 08:36 AM	#11
NOT A 45 Drives: 13 CAMARO 2SS LS3-04 SILVERADO LS3 Join Date: Dec 2021 Location: SOUTHERN MARYLAND Posts: 802	I have long tubes, and high flo's w/npp. I pulled the fuse and the sound is incredible with absolutely no drone on the highway. Don't understand why anyone would want to switch it back and forth unless perhaps you have AFM. That sound in 4 cyl mode is disgusting!