of nitrous systems: dry & wet with four main delivery methods of nitrous systems: single nozzle, direct port, plate, and bar used to discharge nitrous into the plenums of the intake manifold. Nearly all nitrous systems use specific orifice inserts, called jets, along with pressure calculations to meter the nitrous, or nitrous and fuel in wet applications, delivered to create a proper air-fuel ratio (AFR) for the additional horsepower desired. Dry In a dry nitrous system the nitrous delivery method provides nitrous only. The extra fuel required is introduced through the fuel injectors, keeping the manifold dry of fuel. This property is what gives the dry system its name. Fuel flow can be increased either by increasing the pressure or by increasing the time the fuel injectors remain open. Dry nitrous systems typically rely on a single nozzle delivery method, but all of the four main delivery methods can be used in dry applications. Dry systems are not typically used in carbureted applications due to the nature of a carburetor's function and inability to provide large amounts of on-demand fuel. Dry nitrous systems on fuel injected engines will use increased fuel pressure or injector pulsewidth upon system activation as a means of providing the correct ratio of fuel for the nitrous. Wet In a wet nitrous system the nitrous delivery method provides nitrous and fuel together resulting in the intake manifold being "wet" with fuel, giving the category its name. Wet nitrous systems can be used in all four main delivery methods. In wet systems on fuel/direct injected engines care must be taken to avoid backfires caused by fuel pooling in the intake tract or manifold and/or uneven distribution of the nitrous/fuel mixture. Port and direct fuel injection engines have intake systems engineered for the delivery of air only, not air and fuel. Since most fuels are heavier than air and not in a gaseous state when used with nitrous systems it does not behave in the same way as air alone; thus the possibility of the fuel being unevenly distributed to the combustion chambers of the engine causing lean conditions/detonation and/or pooling in parts of the intake tract/manifold presenting a dangerous situation in which the fuel may be ignited uncontrollably causing catastrophic failure to components. Carbureted and single point/throttle body injected engines use a wet manifold design that is engineered to evenly distribute fuel and air mixtures to all