Pressure estimating system in the exhaust manifold of a diesel engine and method for calibrating said system

The system has an acquisition unit (40) for acquiring value of pressure in a cylinder of a diesel engine for predetermined crankshaft angles. An estimation unit (48) for estimating an average and maximum gas pressure in an exhaust manifold according to the acquired pressure value. The pressure in the cylinder represents average and maximum gas pressure in the manifold for corresponding angles. An independent claim is also included for a method for calibrating an average and maximum gas pressure estimating system.