Afm
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 24,099
Likes: 1,327
From: Spring Texas
Afm
Is GM going to continue with the AFM in the C8? I ask this because of this in C&D:
"The additional output, which jumps from 455/460 hp and 460/465 lb-ft in the LT1 to 490/495 hp and 465/470 lb-ft in the LT2 (the higher figures are with the optional performance exhaust, which adds a second set of flapper valves)"
The words "second set of flapper valves", to me, means that the C8 WILL have AFM stuff in it.
Anyone know for sure?
"The additional output, which jumps from 455/460 hp and 460/465 lb-ft in the LT1 to 490/495 hp and 465/470 lb-ft in the LT2 (the higher figures are with the optional performance exhaust, which adds a second set of flapper valves)"
The words "second set of flapper valves", to me, means that the C8 WILL have AFM stuff in it.
Anyone know for sure?
Drifting
Joined: Aug 2000
Posts: 1,601
Likes: 52
From: Jefferson City MO
Is GM going to continue with the AFM in the C8? I ask this because of this in C&D:
"The additional output, which jumps from 455/460 hp and 460/465 lb-ft in the LT1 to 490/495 hp and 465/470 lb-ft in the LT2 (the higher figures are with the optional performance exhaust, which adds a second set of flapper valves)"
The words "second set of flapper valves", to me, means that the C8 WILL have AFM stuff in it.
Anyone know for sure?
"The additional output, which jumps from 455/460 hp and 460/465 lb-ft in the LT1 to 490/495 hp and 465/470 lb-ft in the LT2 (the higher figures are with the optional performance exhaust, which adds a second set of flapper valves)"
The words "second set of flapper valves", to me, means that the C8 WILL have AFM stuff in it.
Anyone know for sure?
Safety Car
Joined: Sep 2011
Posts: 3,913
Likes: 395
From: Cary NC
The Order Guide describes the engine thusly:
"LT2 Engine, 6.2L V8 DI, high-output, Variable Valve Timing (VVT), Active Fuel Management (AFM)"
Car and Driver is talking about the NPP performance exhaust.
"LT2 Engine, 6.2L V8 DI, high-output, Variable Valve Timing (VVT), Active Fuel Management (AFM)"
Car and Driver is talking about the NPP performance exhaust.
Instructor
Joined: Jun 2019
Posts: 222
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From: South Florida
Safety Car
Joined: Sep 2011
Posts: 3,913
Likes: 395
From: Cary NC
The OP quoted Car & Driver making a statement that applies to NPP, not AFM. The exhaust bypass valves of NPP improve horsepower slightly but have nothing to do with cylinder deactivation. The answer to his question is that the LT2 does offer cylinder deactivation.
Last edited by CaryBob; Jul 26, 2019 at 06:29 PM.
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 24,099
Likes: 1,327
From: Spring Texas
You missed the C&D statement that I included that talks about a second set of flappers. Obviously, the FIRST set of flappers is the set of AFM flapper valves.
Safety Car
Joined: Feb 2016
Posts: 4,980
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From: Bainbridge Island WA
Do they come with a can of Blinker Fluid?
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Melting Slicks
Joined: Apr 2008
Posts: 2,063
Likes: 335
From: Massachusetts
Nonsense. He didn't miss anything; you did. Flapper valves in the exhaust train have nothing at all to do with AFM. AFM has to do with cylinder deactivation at suitable times. It shuts off 4 out of 8 cylinders to save fuel. How could you possibly misunderstand that? "AFM Flapper Valves: Do they come with a can of Blinker Fluid?
Do they come with a can of Blinker Fluid?
Burning Brakes
Joined: Sep 2004
Posts: 815
Likes: 75
From: Lincoln CA
St. Jude Donor '16-'17,'19
The new C8 is reported to have AFM. To clarify some of the discussion here, we can look back on six years of C7 history (talking base and Z51 cars, not Z06/ZR1's). The standard non-NPP C7 exhaust has two AFM valves before the mufflers that operate in concert with cylinder deactivation. The NPP exhaust adds two more valves at the exhaust tips that open and close in different operating modes, driving conditions, and rpm's. I expect the C8 will have a similar arrangement.
Ernie
Ernie
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 24,099
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From: Spring Texas
Nonsense. He didn't miss anything; you did. Flapper valves in the exhaust train have nothing at all to do with AFM. AFM has to do with cylinder deactivation at suitable times. It shuts off 4 out of 8 cylinders to save fuel. How could you possibly misunderstand that? "AFM Flapper Valves: Do they come with a can of Blinker Fluid?
Do they come with a can of Blinker Fluid?
Racer
Joined: May 2015
Posts: 475
Likes: 300
From: Utah
I certainly hope GM doesn't decide to abuse the DCT clutches as a means to minimize drivetrain
vibration when in V4 mode like they did with the A8 torque converter clutch. Many believe it is the
underlying cause of A8 shudder issues. If they do, hopefully Range will be able to provide a
solution.
vibration when in V4 mode like they did with the A8 torque converter clutch. Many believe it is the
underlying cause of A8 shudder issues. If they do, hopefully Range will be able to provide a
solution.
Racer
Joined: Jun 2018
Posts: 266
Likes: 207
From: Sarasota Florida
I certainly hope GM doesn't decide to abuse the DCT clutches as a means to minimize drivetrain
vibration when in V4 mode like they did with the A8 torque converter clutch. Many believe it is the
underlying cause of A8 shudder issues. If they do, hopefully Range will be able to provide a
solution.
vibration when in V4 mode like they did with the A8 torque converter clutch. Many believe it is the
underlying cause of A8 shudder issues. If they do, hopefully Range will be able to provide a
solution.
Drifting
Joined: May 2013
Posts: 1,972
Likes: 1,098
From: Texas Hill Country Texas
Nonsense. He didn't miss anything; you did. Flapper valves in the exhaust train have nothing at all to do with AFM. AFM has to do with cylinder deactivation at suitable times. It shuts off 4 out of 8 cylinders to save fuel. How could you possibly misunderstand that? "AFM Flapper Valves: Do they come with a can of Blinker Fluid?
Do they come with a can of Blinker Fluid?
Racer
Joined: Jun 2018
Posts: 266
Likes: 207
From: Sarasota Florida