There is no need to look into it as deep as you are Mao.
We are looking at a 2D graph of Torque vs RPM.
In the fast and the furious world, people look at peak figures. "OMG my car makes 301hp where as yours only makes 299hp". We are all aware that this only makes your e-penis larger on the internet (yay for forums
).
People looking at true performance will look at the torque curve, not the power curve. Again, peak figures tell you nothing about the car. But the area between the curve and the "x-axis / rpm axis" will tell you how the car will perform. Technically (mathematically) it is calculating 'work'. For everyone else it proves that you have a very fat torque curve.
There is no need to physically calculate a number for comparison (easily do-able but not necessary), it is just a visual guide so you can look at various dyno plots and make comparisons.
I tell everyone who asks me advice to ignore peak figures and purely look at this.
I am very interested in your other information as I do love looking at the 3D graphs used in tuning. I'd also be very interested if you have anything that shows higher dyno torque at a non WOT.
If people want a bullshit long theoretical maths excersize, try calculating your hp curve from your turbo compressor map. I've done it for my TD04 and it is a great way to really understand how things connect, what volumetric efficiencies do etc etc.