Quote:
Originally Posted by pete c
You can always spot an ecomodder noob when the topic of warm air intakes is brought up.
It comes from the fact that the rest of the world is trying to squeeze more power out of their engines rather than just better mpg.
To the noobs, of which I sort of am, but, been here long enough to 'get' WAI.....
CAI allows you to stuff more O2 into a cylinder for a given throttle opening. More O2 means more fuel and more power.
You might consider this more "efficient" in that you are making more power. But remember, the name of the game here is to make just enough power to push your car at a desired speed.
So, since power as a function of throttle opening, is higher with CAI, a WAI throttle must be opened further than a CAI throttle to get to the desired power output.
And since pumping losses decrease with throttle opening, the WAI will have lower pumping losses which means higher efficiency.
It requires a different way of looking at things and remembering that it all revolves around pumping losses and possibly better fuel atomization.
I am sure there is a better worded explanation somewhere around here. Perhaps someone could post a link to it.
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Except for the fact that EGR and PCV offset pumping losses to a large degree. A colder air intake with a more closed throttle plate will increase EGR flow thus leading to more trapped mass in the cylinder which in turn reduces heat lost to the cooling system and allows more energy to be extracted from the power stroke. Also as mentioned before a cooler intake charge also reduces energy lost to the cooling system.
If you want more proof, cooled EGR bumps mileage compared to non cooled EGR.