'Smart' power curve on MAN
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by Brian Weatherley • When MAN's much-publicised 550hp-plus Euro-2 vee-10 breaks cover this autumn it will feature an electronically controlled "moveable" power curve that responds automatically to engine load and driving style.
The system, known as ESM, is similar to Cummins' Electronic Smart Power (ESP) which is currently offered as an option on CELECT electronic engines sold in the US—but not in Europe.
ESM adjusts the vee-10's power and torque curve based on information supplied from various sensors on the truck which is fed into a central microprocessor. Outputs can be either raised, or lowered, according to the truck's acceleration, engine load and speed.
In common with MAN's 10 and 12-litre Euro-2 engines the 18.3-litre ESM big vee will have a drive-bywire throttle with no mechanical link between the accelerator pedal and the fuel pump.
When the ESM-equipped truck is running on a level road the power is reduced to a level sufficient to maintain a normal cruising speed. In hilly-terrain, or when pulling away from rest fully-laden, ESM senses the increased power demand based on engine load and throttle position and raises the vee-10's power and torque output to an optimum performance level.
The loaded condition of the vehicle is determined by monitoring the truck's electronically controlled air suspension (ECAS) on the drive axle.
ESM offers the opportunity to prevent driveline and tyre abuse associated with unladen high-horsepower tractors through management of engine revs and traction. The benefit of the system is that power control is automatic.
According to MAN's engineering boss Dr Klaus Schubert: "We must avoid things like wheelspin on the driven axle and the incorrect use of horsepower. As it is automatic it will not have a switch on the dashboard."
In January MAN revealed that its Euro-2 vee-10 could soon be rated up to 600hp and beyond. Schubert will not be drawn on the final ratings but he says it will have a minimum 550hp.
CM expects MAN's ESM vee-10 to be shown for the first time at the Paris Motor Show in September. Its appearance is likely to create new interest in high powered tractors although Schubert insists: "We don't want to have a horsepower race—but we do want to use the ability of the electronics to use an intelligent engine management."