Homepage Garage Wiki Register Social Groups Calendar Search Today's Posts Mark Forums Read
#Camaro6
Go Back   CAMARO6 > CAMARO6.com General Forums > ZL1 Discussions


BeckyD @ James Martin Chevy


Post Reply
 
Thread Tools
Old 02-21-2020, 03:46 PM   #1
ZL1GEEK
 
ZL1GEEK's Avatar
 
Drives: 2018 ZL1 Hyperblue M6, 99 Camaro SS
Join Date: Jun 2018
Location: Virginia
Posts: 36
AFM on the M6 ZL1

I have a 2018 ZL1 with the 6 speed manual, I'm reading that on the manual cars there is no AFM ( active fuel management ) system. However, even after the NPP exhaust fuse pulled at idle the damn car still gets quite. I know with the AFM there are another set of exhaust butterfly valves right after the back axle. They are there to provide back pressure when the AFM goes into 4 cylinder mode correct? So if the manual cars don't have AFM why does my damn car go quite at idle?
I want that obnoxious sound it gives at start-up to stay there.
So if the valves are in fact there and are in use, is there a trick to get those to stay open ( no tune )?
Thanks
__________________

2018 ZL1 M6 Hyper Blue, 2013 ZL1 SOLD, 1999 SS Comp cam, Few bolt on's.
ZL1GEEK is offline   Reply With Quote
Old 02-21-2020, 03:49 PM   #2
Tricksta


 
Tricksta's Avatar
 
Drives: 2018 ZL1 A10
Join Date: Nov 2013
Location: Leipsic,Ohio
Posts: 3,811
no 6th gen ZL1 has AFM. The valves right after the back axle are the normal NPP valves.
__________________
Modifications
GM Dark Tail Lights / 3rd Brake Light & Reflectors | LED Reverse Lights | Diode Dynamics Side Markers | Borla "ATAK" Cat Back Exhaust
Tricksta is offline   Reply With Quote
Old 02-21-2020, 03:52 PM   #3
Tricksta


 
Tricksta's Avatar
 
Drives: 2018 ZL1 A10
Join Date: Nov 2013
Location: Leipsic,Ohio
Posts: 3,811
furthermore the reason it goes quiet at idle is because on initial startup the RPMS are higher than idle speed, and as it begins to warm up the idle calms down.

shorthand if you want more noise, change the exhaust or add headers.
__________________
Modifications
GM Dark Tail Lights / 3rd Brake Light & Reflectors | LED Reverse Lights | Diode Dynamics Side Markers | Borla "ATAK" Cat Back Exhaust
Tricksta is offline   Reply With Quote
Old 02-21-2020, 04:19 PM   #4
ZL1GEEK
 
ZL1GEEK's Avatar
 
Drives: 2018 ZL1 Hyperblue M6, 99 Camaro SS
Join Date: Jun 2018
Location: Virginia
Posts: 36
Interesting, yeah the more i read through i see where this was up for debate. I see where some have proved it is not on any ZL1. It's cold out now i went and tried to capture what i was hearing, I see what your saying about the RPM's are higher at start up, this is obvious. However what im hearing is a distinct sound of the exhaust getting muffled as if the NPP valves just closed. usually on a warm day it happens maybe 10 seconds after start-up.

Thanks for the AFM update though.
__________________

2018 ZL1 M6 Hyper Blue, 2013 ZL1 SOLD, 1999 SS Comp cam, Few bolt on's.
ZL1GEEK is offline   Reply With Quote
Old 02-21-2020, 04:42 PM   #5
radz28
Petro-sexual
 
radz28's Avatar
 
Drives: Ultra-Grin
Join Date: Oct 2006
Location: Crazy Coast
Posts: 15,155
It is also my understanding the timing is retarded at start-up to give it some rasp and aggressive sound. The timing comes back after a little bit of time, which might be what you're hearing.
__________________

'20 ZL1 Black "Fury"
A10, PDR, Exposed CF Extractor
Magnuson Magnum DI TVS2650R // TooHighPSI Port Injection // FF // Katech Dual In-Tank // Soler 103 // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs
radz28 is offline   Reply With Quote
Old 02-22-2020, 12:22 AM   #6
jvandy50
 
jvandy50's Avatar
 
Drives: 18 ZL1-1LE, 10 JKU
Join Date: Jul 2018
Location: AR
Posts: 583
did you pull the correct fuse? I’m guessing so, just might double check. i couldn’t handle leaving my stainless works NPP catback in track mode just to hear it quiet down at certain RPMS. I could not believe it wouldn’t simply leave the valves open...so i have a catback i paid extra to get the valves, but don’t use them lol.
jvandy50 is offline   Reply With Quote
Old 02-23-2020, 08:53 AM   #7
69pro-touring
 
69pro-touring's Avatar
 
Drives: 2017 ZL1 6MT
Join Date: Dec 2018
Location: Louisiana
Posts: 43
SW Exhaust

Quote:
Originally Posted by jvandy50 View Post
did you pull the correct fuse? I’m guessing so, just might double check. i couldn’t handle leaving my stainless works NPP catback in track mode just to hear it quiet down at certain RPMS. I could not believe it wouldn’t simply leave the valves open...so i have a catback i paid extra to get the valves, but don’t use them lol.
Jvandy how are you liking the stainless works exhaust? Is it worth the upgrade over the stock suitcase?
69pro-touring is offline   Reply With Quote
Old 02-24-2020, 12:05 AM   #8
jvandy50
 
jvandy50's Avatar
 
Drives: 18 ZL1-1LE, 10 JKU
Join Date: Jul 2018
Location: AR
Posts: 583
Quote:
Originally Posted by 69pro-touring View Post
Jvandy how are you liking the stainless works exhaust? Is it worth the upgrade over the stock suitcase?
I still like the sound, but am considering adding headers. It is THAT non-obnoxious lol. There is a drone zone at a certain RPM that you can easily avoid, this also does not bother me...just thought I’d mention it as it seems to be at the forefront of exhaust concerns.

I wanted the option to not piss off my neighbors, and loved stainless works stuff on my 16 GT. Borla was meh and not many other NPP options. That said, i don’t use it...even track mode would quiet it down at certain lower RPMs and i just couldn’t believe it. My fuse is still in my console and the car sounds great.

I have a couple clips posted somewhere, but if you’re wanting anything specific, just let me know and when the weather cooperates I’ll fire up the GoPro.
jvandy50 is offline   Reply With Quote
Old 02-24-2020, 07:28 AM   #9
ego74
 
Drives: '21 BMW M4, '21 BMW X5 M Comp
Join Date: Aug 2016
Location: NJ
Posts: 21
Quote:
Originally Posted by radz28 View Post
It is also my understanding the timing is retarded at start-up to give it some rasp and aggressive sound. The timing comes back after a little bit of time, which might be what you're hearing.
this is correct. while my zl1 (with borla exhaust) is loud on a cold start, my m4 (with awe exhaust) can literally wake the dead. and the m4 stays retarded, and therefore louder, for longer.

the reason the timing is retarded on cold start is to allow hotter exhaust gases out into the exhaust to warm up the cats, which work better at higher temps, to minimize emissions. there's no mechanical reason for the timing adjustment, and a lot of tunes actually take that out of the startup sequence.
ego74 is offline   Reply With Quote
 
Post Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:31 AM.


Powered by vBulletin® Version 3.8.9 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.