What is fuel pump index method and turbocharger speed method to calculate power of an engine?

2. Turbocharger speed method to calculate power

This method is more accurate than the Fuel pump index method. Chart I: draw a horizontal line from the observed scavenge air temp (Tscav) value and an inclined line from the observed turbocharger speed. From the intersection point, draw a vertical line down to the nomogram curve and then a horizontal line to the vertical line from the observed ambient pressure (point x in the ambient pressure scale). Finally, a line is drawn parallel with the inclined ‘ambient pressure correction’ lines. The effective engine power can then be read on the scale at the right hand side, i.e. 8,000 bhp.

FIG: TURBOCHARGER SPEED METHOD