Nitrous is FI? Take notes! You're getting SCHOOLED by Tracy!!!Originally Posted by TIGERJC
http://en.wikipedia.org/wiki/Forced_induction
Forced induction can be used to improve the power, efficiency, emissions, or combinations of same, without much extra weight and minimal modifications to the engine architecture. The two most common forms of forced induction are turbochargers and superchargers, which both compress the air entering the cylinders, but use different methods to obtain the requisite power. Functionally, they are much the same. Since only so much power can be had from a given amount of gasoline, the more gasoline can be burned in the cylinder, the more power can be produced. However, simply adding more gas beyond the optimal air/fuel ratio (commonly called "running rich") does nothing for power. An engine can only take in so much when breathing air at atmospheric pressures, since the capacity and number of cylinders is non-variable. Hence, the only way to get more air into the cylinder, and therefore produce more power, is to increase the pressure at the intake.
All we've considered up to now is increased power, so how does forced induction improve emissions or efficiency? One of the primary concerns in internal combustion emissions is a factor called the NOx fraction, or the amount of nitrogen/oxygen compounds the engine produces. High combustion temperatures lead to a lower NOx fraction, and since gasses heat when compressed, the more gas is compressed in a given volume, the hotter it will get, and the lower the NOx fraction will be. Since forced induction increases the amount of gas being compressed, it increases the heat generated when compression occurs. Since colder air is denser, it is most desirable, from a power standpoint, to have cold air coming in, but better from an emissions standpoint if the air is hot. In a perfect world, incoming air would be frigid, and the compression would be high enough to dramatically and rapidly increase cylinder temperatures, reducing emissions significantly.
Two of the commonly used forced induction technologies are turbochargers and superchargers. They differ primarily in the power source for the compressor. There is a difference between forced induction and power adders. A power adder is anything that improves an engine's power output, which does not necessarily mean increasing charge density. Oxidizing technologies such as nitrous oxide injection systems provide improved power, but are not a form of forced induction.
Reps to Tracy!
Reply With Quote