C7 cylinder deactivation

[RussTeens]

Keith at Eurovettes carried out a re-programme of my 2017 GS Auto at the nationals specifically to disable the cylinder deactivation. This was due to the constant swapping to 4 cylinders even at low speed, really annoying. I also have little confidence that driving a car on 4 cylinders in the long term is good for the engine. Lets not forget the only reason this technology was developed was to fudge the MPG and emissions figures to increase GM's overall MPG average across the whole range.
My car is a US import so the deactivation was aggressive. Since the alteration the car feels smoother during acceleration through all gears, pulls better from low speed as there is not the momentary heistancy whilst 8 Cyl's come back on line, and the fuel consumption has only decreased by approx 1 mpg, which I can live with.

The remap is reversible, Keith kept a copy of the original programme/tune.

Can see how that would be annoying. When in 4th at 30 to 40 mph on smaller roads, mine would swap to 4 cylinders so I tend to swap into touring mode most of the time which on my car deactivates the cylinder shut down. It didn't feel right to me it cutting in out out all the time. I can see how on an auto or US spec car that would be really annoying. As you say 1 mpg is not really worth worrying about. I'll have a play next time I'm on a motorway and see what difference it makes.

 

[Roscobbc]

That's interesting. Keith has been a long term Corvette "good guy". Given he's been selling one or two US market C7s in UK it's interesting that he's not advertising AFM delete on the forum as a service. I guess if it's done as a paid service that can open up a whole Pandora's Box of potential liability issues, given some engines appear to have failed in this way after AFM delete. (That's also my guess of why Ian Allan don't do it.)

If it ain't broke (or at least 'partly' broke) as a 're-programmer 'don't fix it and potentially land yourself other unreleated issues?

 

[teamzr1]

Since I started keeping records via my custom tuning process, saved just about 10,000 OBD2 scanner recordings I analyzed

Not one going back to late 1990s GM vehicles, most of them F & Y body has had engine problems when I turned off DoD/AFM
Very simply, the PCM (engine controller) believes the engine does not have DOD so is not commanding any of its functions
thus the engine valve train functions as they always have pre DOD/AFM

 

[UKBeancounter]

Ian Allen are official GM / Chevrolet Europe sellers. Given that any ECU alteration usually invalidates the warranty I am not surprised they don't want to touch things.
Not read anything about engine failures after AFM delete, only the GM service/recall notices on what dealers should do when lifters seize in the head due to AFM malfunctioning. If its going to blow up, its going to blow up !

 

[Rich]

Not a Corvette, but I have had an AFM disabler on my Camaro for 3 years. Same engine as the C7 but different gearbox. Wouldn't be without it. The vibration through the transmission is noticeable when it is unplugged. Fuel economy is irrelevant and minimal anyway

 

[teamzr1]

GM even does not want 4/8 cyl crap
Notice on Z06 and ZR1 engines do not have DOD/AFM as already have to pay a gas guzzler tax
so it is clear it is all about games as to federal MPG mandates and politics

If you drove through areas where the elevation changes up/down are or at higher elevations where engine performance output is less
would you want to do that with one 1 or 2 legs
Same thing with DoD/AFM changing loads onto auto tranny
where Hp/Tq is half, but the mass going up hill is worse as load

 

[Digger John]

In my euro spec C7 Grand Sport the AFM only operates in Ecco mode so i run in touring mode all the time for general driving so never switches to V4 mode.

 

[mickn]

In my euro spec C7 Grand Sport the AFM only operates in Ecco mode so i run in touring mode all the time for general driving so never switches to V4 mode.

This is exactly what I do in my '18 Grand Sport