Quote:
Originally Posted by mechman600
Usually true. But adding boost to a diesel will not necessarily increase efficiency either if it isn't too rich without boost in the first place. It will not necessarily increase power either, unless you fuel it more. I've seen it a million times on the dyno - putting vice-grips on the wastegate line to increase "power" (as if boost is an indication of power) only to see power actually drop slightly.
|
As long as you don't expend more energy creating the boost than it returns increasing boost will always improve efficiency in a diesel. If you had a way to generate boost that was 100% efficient it would improve efficiency and power up until the point the air starts to liquify under the pressure. The main reason more boost improves efficiency is you have more working fluid mass to heat and thus more fuel energy going into heating the working fluid (air) and less energy going into heating the engine block.
You will however get diminishing returns as you increase the boost.