C7 engine management system question
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Pro
Joined: Mar 2012
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From: South Eastern MI Michigan
C7 engine management system question
I just put some money down on a torch red 2LT C7. I expect to see it at end of June, or early July. My wife and I are leaving behind a blade sliver 2009 1LT base with the Z51 package.
I have already asked a question about "will I be disappointed in the different "Standard" suspension and the answer seems to be that I will not.
My next question is about the engine management system. I have read articles that suggest when the engine goes into the "Econo" mode the valves in four of the cylinders simply close and fuel is no longer delivered. That, to my simple mind makes no sense because the other four cylinders would forcing the disabled cylinders through their compression stroke. This seems to me that in this condition, all 8 cylinders would be very unhappy.
I have also read that the engine management system simply reduces the amount of fuel that is delivered to four of the eight cylinders.
Also: I am getting an automatic transmission. Does that mean that I won't be able to shut this system off unless I am in the Paddle shift mode?
Does anyone know how this system really works?
I have already asked a question about "will I be disappointed in the different "Standard" suspension and the answer seems to be that I will not.
My next question is about the engine management system. I have read articles that suggest when the engine goes into the "Econo" mode the valves in four of the cylinders simply close and fuel is no longer delivered. That, to my simple mind makes no sense because the other four cylinders would forcing the disabled cylinders through their compression stroke. This seems to me that in this condition, all 8 cylinders would be very unhappy.
I have also read that the engine management system simply reduces the amount of fuel that is delivered to four of the eight cylinders.
Also: I am getting an automatic transmission. Does that mean that I won't be able to shut this system off unless I am in the Paddle shift mode?
Does anyone know how this system really works?
Last edited by dckotwicki; May 25, 2014 at 08:38 AM.
Safety Car
Joined: Aug 2012
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Both intake and exhaust valves are closed on the inactive cylinders so the air inside is compressed however this also means the piston is pushed back down by this same compressed air so you aren't actually losing the energy needed to compress the air. This closed system also helps retain heat in the cylinder.
AFM is not only load dependent but there are also temperature and time variables that control activation. One of the introductory pieces stated that AFM would cycle off for a short time after 10 minutes of operation and it would also be disabled if cylinder temperature dropped too much.
Modern AFM has been used in a number of GM engines (not to be confused with the much older and different Cadillac 8-6-4 system) and each iteration seems to be a little smoother and less intrusive in operation.
AFM is not only load dependent but there are also temperature and time variables that control activation. One of the introductory pieces stated that AFM would cycle off for a short time after 10 minutes of operation and it would also be disabled if cylinder temperature dropped too much.
Modern AFM has been used in a number of GM engines (not to be confused with the much older and different Cadillac 8-6-4 system) and each iteration seems to be a little smoother and less intrusive in operation.
Last edited by NSC5; May 25, 2014 at 10:23 AM.
Racer
Joined: May 2014
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Congrats on the order! Another torch red guy/gal!
If you just ordered and it wasn't in the system at the dealership already I don't think you'll see the car in June if I had to guess but July would certainly be a possibility!
If you just ordered and it wasn't in the system at the dealership already I don't think you'll see the car in June if I had to guess but July would certainly be a possibility!
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Joined: Mar 2012
Posts: 639
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From: South Eastern MI Michigan
The vehicle was in the system. No one had claimed it yet.
Le Mans Master
Joined: Sep 2003
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From: Longview Texas
I don't plan to ever let mine go into 4 cylinder mode, but mine is a manual transmission.
Others say the Stingray system is seamless, but if you do not like it, a company already makes a module that plugs into the diagnostic port to bypass the mode.
http://www.rangetechnology.com/pages/v8
Others say the Stingray system is seamless, but if you do not like it, a company already makes a module that plugs into the diagnostic port to bypass the mode.
http://www.rangetechnology.com/pages/v8
