Josh

iTrader: (9)

Theoretically, if one were to log horsepower, RPM, air/fuel ratio, and injector duty cycle on two different vehicles with exactly the same hardware configuration except injectors and confirm that, given identical amounts of air and fuel, all the parameters on both vehicles were the same aside from the injector duty cycle, what would cause the vehicle with smaller injectors to make less power than the vehicle with larger injectors? Again, assuming all other factors are the same, including AF ratio.

Josh

Bombguy99z28

With the tolerances used in building these engines as well as margin of error on the dyno I doubt you would be able to concretely say if any noticed power difference between two different engines with the same parts was due to the injectors. The only reason I could think of that might cause injectors to dyno higher/lower would be the spray pattern.

Even if you saw a few hp difference, it could be due to many factors not neccessarily related to the engine parts. If you saw more than a few hp difference I probably wouldn't think it was the injectors.

turbolx

Relatively small changes in measured power may come from superior fuel atomization. In this case, a larger injector that sprays on a closed (YES, closed!) intake valve, causing more of the fuel volume to evaporate completely before entering the cylinder may have better combustion characteristics than a smaller injector that needs to continue its flow time past the intake valve opening point. You'd only find relatively small increases here at WOT since port velocity is up there and charge motion is also usually pretty good, but it matters more a cruise and light throttle.

To answer your main question, as others indicated, there may be other physical differences (friction, build tolerances, fuel quality, etc...) between the two engines in question.