[redyaris]

Originally Posted by elemein

You are a little more precise.

20% throttle does not let by 200 cc of air; it still lets in 1000 cc, but the 20% throttle makes that particular volume of air have the density and pressure of 200 cc at atmospheric.

So yes, you are correct, but the math still works out the same.

That is not corect. You would have to do some testing or find some sort of chart, to see what the mass of air traped in the cyclinder is at % throatle. There is no liniar relationship between % throatle position and mass of air traped in the cylinder under variouse % throatle.