hollus wrote:How can the engine go over max revs? Isn't it electronically controlled?
Yes, the ECU is programmed never to exceed 18,000 RPM. But the shut-down process is not immediate or sudden, most likely it starts to shut down fuel injectors. But in a tow, I believe that when the engine hits 18K, if just one cylinder bank is shut down, the engine may provide enough power to stay in the draft, and go just a little bit faster.
The ignition is cut when the speed limit is reached, so the engine power is cut immediatly. So you really want to avoid hitting the engine speed limit.
I would guess that the oil pump pressure, scavenge, and deaerate functions probably produce a parasitic loss of about 6 to 8 HP at the crank at max rpm. The coolant pump about the same. And the alternator loss is probably less than 1 HP.
So maybe 12 to 14 HP total for a brief period? Just my guess.
A dry sump pump consumes about 7 hp, half due to scavenging and half due to the pressure pump. But in total the pump actually gives you power since the scavenge pumps reduce crankcase pressure to roughly a half atmosphere, which in turn increase engine output.
The alternator is also quite small, 30 amps or something like that. The battery is also small, so I don't know if the battery could handle the load from the system without the alternator when the engine is run at full load.