How did Ford get 400hp+

[DGthe3]

Originally Posted by 8cd03gro

You have to take "effective" displacement into account. Displacement is literally the volume of the fuel/air mixture in the combustion chamber. When you increase pressure without increasing volume, you are effectively increasing displacement. Because of many factors like heat radiation, this is not an exact truth, but in theory a 2.0L engine boosted to 14.7PSI above atmospheric or +1 ATM is effectively a 4.0L engine. There isn't a replacement for displacement, but there is a replacement for physical size of the combustion chamber and that is pressure.

Yes, forced induction, and positive displacement superchargers in particular, have the end result of practically increasing an engines displacement. Which is why I made sure to specify that I was talking about naturally aspirated engines.

Originally Posted by DGthe3

The cost is part of it though. And with naturally aspirated engines, there is a big difference between a small engine with a high specific output vs a large engine with low specific output even if both make the same peak power. Namely torque, powerband, and average output.

[8cd03gro]

Originally Posted by DGthe3

Yes, forced induction, and positive displacement superchargers in particular, have the end result of practically increasing an engines displacement. Which is why I made sure to specify that I was talking about naturally aspirated engines.

Oh, I know, I was using boost as a more extreme example of how important MEP is. I didn't mean to make it seem like I was correcting you. More like adding to your statement.