Quote:
Originally Posted by speedracing944
Why it is true the AFR stays the same (I am not debating that) the pumping efficiency decreases. This in turn decreases the thermodynamic efficiency which in turn decreases the efficiency of the engine (mass flow being equal for "dirty" filter vs. "clean" filter)
Take a garden hose and suck on one end of it while the other end is free of obstruction. Then take your sock, coat it with dirt and mud, tie it on the end of the garden hose and suck on the free end. You will have to "work" harder sucking on the garden hose in scenario II to get the same amount of mass flow. The increased "work" or energy exerted for the same effect will reduce your "sucking" efficiency.
Oh boy this is getting too detailed 
Speedy |
Apparently the thermodynamic efficiency doesn't make enough difference to matter. Also, with the intake restricted, the maximum gas usage is reduced.