[teddyca]

My Camaro doesn't have NPP but obviously still has a set of valves in the factory x pipe. On Wed I am having the Borla xpipe https://www.borla.com/products/chevr...ing-pipe-60610 and I would like to be able to open and close the valves. Systems like mild2wild, etc. state only for NPP systems so I am wondering if I can somehow control these. Also note I "think" you can disable them in HP Tuners as well but have not actually looked into that much yet.

[Mark114]

Yes, you can disable the AFM valve by tuning the BCM. Your signature says you have a Magnuson TVS2300 so maybe AFM has already been tuned out of the ECM and BCM? If not, the AFM valve is actually two pieces: the metal valve and a black electronic actuator as shown in the picture below. I believe you just need to remove the actuator from the OEM exhaust and bolt it to the AFM valve on the Borla exhaust. Then everything will work the same as it did with the OEM exhaust.

[avalonandl]

Your confusing NPP valves ( switchable exhaust) with AFM valves when the engine goes into economy mode.

Do a search....

[ember1205]

Originally Posted by teddyca

My Camaro doesn't have NPP but obviously still has a set of valves in the factory x pipe. On Wed I am having the Borla xpipe https://www.borla.com/products/chevr...ing-pipe-60610 and I would like to be able to open and close the valves. Systems like mild2wild, etc. state only for NPP systems so I am wondering if I can somehow control these. Also note I "think" you can disable them in HP Tuners as well but have not actually looked into that much yet.

NPP is a pair of controllable actuators AT THE TAIL PIPES that allows you to open the outer tips and effective bypass the bulk of the baffling from the mufflers.

The valves you are referring to are only present in automatic transmission cars and are related to the AFM that switches the engine between V4 and V8 mode. The two are completely unrelated.

There is zero value in trying to "control" the valves that you have. And if you install a pipe that effectively eliminates the actuators in the factory pipe, you have to have a tune done to disable AFM or the car simply won't run right and it will throw CEL's.

[Zr8000]

Originally Posted by ember1205

NPP is a pair of controllable actuators AT THE TAIL PIPES that allows you to open the outer tips and effective bypass the bulk of the baffling from the mufflers.

The valves you are referring to are only present in automatic transmission cars and are related to the AFM that switches the engine between V4 and V8 mode. The two are completely unrelated.

There is zero value in trying to "control" the valves that you have. And if you install a pipe that effectively eliminates the actuators in the factory pipe, you have to have a tune done to disable AFM or the car simply won't run right and it will throw CEL's.

You no longer new a tune to disable a the afm. Holly has a new plug that will do it.

[ember1205]

Originally Posted by Zr8000

You no longer new a tune to disable a the afm. Holly has a new plug that will do it.

That would likely be tricking the ECM into thinking the motor is at temp or something, and that could mess up emissions overall and MPG. Not sure if that would be 'better' than a tune...

[teddyca]

LOL Thanks guys for the educational piece and guidance. Funny thing is You all are 100% correct. No NPP, this car didnt have this option, these are the front AFM valves. Here is what I ultimately am trying to do. On my C7 I know there is a switch you can buy "mild to wild" that controlled what I assumed were the NPP valves (which that car has), but with a full exhaust its already loud enough. With my Camaro is sounds rowdy at start up then tames down a bit. I now ASSUME I am referencing the AFM valves are closing. I would love to control them and be able to leave them open. I do have HP Tuners and I do have credits for the car if I can manage them valves there???

[MrRuss]

Starting again...... AFM valves have nothing to do with controlling the sound of your exhaust. NPP and "Mild to Wild" are completely different. AFM valves are strictly used when your car goes from V8 to V4 mode. The AFM valves close partially to allow more back pressure, they don't close completely. If you want to control your exhaust sound you will need to add an after market system that mimics NPP and simply not worth it IMO.

Is this the car you are talking about from your signature?

"17 Camaro 2SS 50th edition. Round 2- 8/2019 550/600 RWHP, Magnuson TVS2300, Rotofab Intake, Corsa Xtreme, Air Lift P3 System, 20" Stance SF-07, smoked lights all the way around, Rockford Fosgate system."

I would guess that the V8 to V4 mode has already been tuned out, making the AFM valves always open anyway. If that is the case, get the connecting pipes without AFM valves, less restriction.

[wwiiavfan]

Originally Posted by ember1205

That would likely be tricking the ECM into thinking the motor is at temp or something, and that could mess up emissions overall and MPG. Not sure if that would be 'better' than a tune...

Several companies make AFM delete modules. I use the Range one that plugs into the OBD port. Been using it for probably 10k miles. Works great, no CELs or any other errors. It does not, however , have any discernible effect on the exhaust sound. Possibly a few more crackles and pops, but it’s debatable.

[arpad_m]

Originally Posted by teddyca

LOL Thanks guys for the educational piece and guidance. Funny thing is You all are 100% correct. No NPP, this car didnt have this option, these are the front AFM valves. Here is what I ultimately am trying to do. On my C7 I know there is a switch you can buy "mild to wild" that controlled what I assumed were the NPP valves (which that car has), but with a full exhaust its already loud enough. With my Camaro is sounds rowdy at start up then tames down a bit. I now ASSUME I am referencing the AFM valves are closing. I would love to control them and be able to leave them open. I do have HP Tuners and I do have credits for the car if I can manage them valves there???

I think I see where you are coming from Teddy, the startup sound is much wilder than what you get when the car has already idled x seconds, even on your non-NPP car, and it would be nice to keep that going, right?

I'll leave it to the pros to post a comprehensive answer, but as far as I know, this is called "exhaust rumble", set in the tune for emissions, and only lasts for a certain time after startup, there is no way to extend its duration.

As many others already stated above, the AFM valves, while they do reuse the exact same components as their NPP counterparts, have no say or function related to exhaust sound. Sorry

[ember1205]

On cold start, a lot of extra fuel is dumped into the engine and everything runs "wide open" for a short burst to start brining the exhaust components up to temp so that everything is working as efficiently as possible. If the engine is not completely cold, this doesn't happen.

As far as the "Mild to wild" stuff, that's TOTALLY different from NPP. NPP is sort of a "partial bypass" of the muffler (it's a more direct path out, but it still passes through the main housing of the muffler) whereas the "Mild to wild" stuff is basically like straight pipes. Flipping the mode to "Wild" effectively opens a valve at a bend in the exhaust pipe -before- the muffler and you're running without anything passing through the muffler at all.

[teddyca]

Damn it fellas that is the most I have learned in awhile lol. I really appreciate the extra effort here to explain exactly whats happening. While I love the "cold start" sound, I have no desire to throw a bunch of extra fuel at the car. Remember I live in Cali so a tank of gas is somes paycheck. lol With all that said, I will let AFM do its job and leave well enough alone. With the Maggie, borla Xpipe, and Corsa Xtremes this thing is not exactly quiet as it is. LOL