RootsStyle

how exactly does the displacement on demand, a.k.a cylinder shutoff, work? can you take a dod engine and cancel the dod?

BlueMagicSS

iTrader: (4)

I'm not sure if you are able to turn it off but I would think you could... what it does is it turns off the fuel injectors to those specific cylinders that it wants to turn off... It's a computer tuning scenario so I would think if you have the right tuner he can delete out those tables for that particular thing...

Bryan921SS

I know you are new and all but try searching....or come on down and see ous near the bottom of the main page in the LS4 forum.....

DOD/AFM can be shut off...

"During light load conditions while in 3rd or 4th gear the ECM will shut down cylinders 1, 4, 6, and 7 to put the engine in V4 mode. The engine will not enter V4 mode while cranking, idleing, or heavy acceleration. To shut down the cylinders the intake and exhaust valves stay closed and the fuel injectors stop feeding gas. The ECM times the shutdown so that each deactivated cylinder keeps the exhaust charge from the previous combustion cycle. This pressure on the pistons keeps them from rocking around in the cylinder causing vibration and oil consumption. Complete cylinder deactivation is accomplished in about 250 milliseconds."

More info in the LS4 section of LS1 tech.....

RsSean

iTrader: (27)

Well above this about summed it up. The lifters shrink together when this happens to keep the valves shut, because the cam will contuine to turn regraudless of V4 mod. I thought I would add that.