22-12-2012, 04:50 AM
I haven't got any specific info for the third piston shut-off, but i didn't notice any real difference when i unplugged mine. If it's going to be active for cruising i should think it'd be set with similar parameters to the egr, so part-throttle conditions at 60-70mph.
Tom, the main point of it is to reduce pumping losses at low engine load, pressurising fuel to over 1000bar is no small job, uses a fair bit of torque to run the pump. In theory, if you can shut down one of the pistons when it's not needed you can reduce the load on the engine and therefore save fuel. Allegedly, that is... As said on TDOC, it's probably 50% gimmick, but it may be possible to discern its effect - if any - with empirical testing, anyone fancy giving it a go?
Tom, the main point of it is to reduce pumping losses at low engine load, pressurising fuel to over 1000bar is no small job, uses a fair bit of torque to run the pump. In theory, if you can shut down one of the pistons when it's not needed you can reduce the load on the engine and therefore save fuel. Allegedly, that is... As said on TDOC, it's probably 50% gimmick, but it may be possible to discern its effect - if any - with empirical testing, anyone fancy giving it a go?