These are three basic
types of nitrous systems: dry, wet, and direct port. The
most misunderstood is the "dry" type of system. A "dry"
nitrous system simply means that the fuel required to make
additional power with nitrous will be introduced through the
fuel injectors (remember, fuel makes power, nitrous simply
lets you burn more of it). This keeps the upper intake dry
of fuel. We accomplish this by two methods. First, is to
increase the pressure to the injectors by applying nitrous
pressure from the solenoid assembly when the system is
activated. This causes an increase in fuel flow just like
turning up the pressure on your garden hose from 1/2 to
full. The second way we can add the required fuel is to
increase the time the fuel injector stays on. This is
accomplished by changing what the computer sees, basically
tricking the computer into adding the required fuel. In
either case, once the fuel has been added the nitrous can be
introduced to burn the supplemental fuel and generate
The second type of nitrous kit is the wet style of kit.
These kits include carburetor plate systems and add nitrous
and fuel at the same time and place (normally 3-4" ahead of
the throttle body for fuel injected applications or just
under the carb as with plate systems).
of system will make the upper intake wet with fuel. These
systems are best used with intakes designed for wet flow and
turbo/supercharged applications.The reason for this is the
fact that fuel flows differently than air or nitrous. This
difference in flow characteristics can lead to distribution
problems and, in some cases, intake backfires. Intakes
designed for wet flow (such as with carburetors) cause much
less separation of the nitrous/air, and fuel. Because modern
fuel injection intakes are designed to flow air only, they
have tighter turns and a more compact design as a result.
Thus, they generally do not make good candidates for wet
flow nitrous systems.
The last type of system is the direct port system. Just as
it's name implies, it introduces the nitrous and fuel
directly into each intake port on an engine. These systems
will normally add the nitrous and fuel together through a
nozzle known as a Fogger nozzle. The fogger nozzle mixes and
meters the nitrous and fuel delivered to each cylinder. This
is the most powerful and one of the most accurate type of
systems. This is due to the placement of the nozzle in each
runner, as well as the ability to use more and higher
capacity solenoid valves.
A direct port system will have a distribution block and
solenoid assembly which delivers the nitrous and fuel to the
nozzles by way of connecting tubes. Because each cylinder
has a specific nozzle and jetting (both nitrous and fuel),
it is possible to control the nitrous/fuel ratio for one
cylinder without changing that of the other cylinders. These
systems are also one of the more complicated systems when
installation is considered, as the intake must be drilled,
tapped, and the "plumbing" made to clear any existing
obstructions. Because of this and the high output of these
systems, they are most often used on racing vehicles built
for the strain of such high horsepower levels.