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Airflow Snorkels - everything you wanted to know

The History
Snorkels have been around for a long time on vehicles and water craft. From World War 1 on they have been used on tanks and submarines and then on agricultural vehicles and transport in the 1920’s and 30’s.
All were used to introduce air into the engine of the vehicle which would be free of water and contaminants.
In more recent times we have started using snorkels for 4WD so they could go through a river crossing without causing damage to or the destruction of the engine.

Airflow Snorkels are much more.
Fuel efficiency, economy and getting the most out of the vehicle is what Airflow Snorkels aim to achieve and yes, to go through that river crossing.
To this end Airflow has been conducting airflow, friction loss and performance testing on our own products and other air induction manifolds for many years.
While in the past our focus has not always been on aesthetic design, the performance of the snorkels has been foremost.
The result of this testing in conjunction with new styling means Airflow has a range of cold air ram induction manifolds that will increase the performance and efficiency of your 4WD.
Not all snorkel body designs produce a cold air induction effect that increases power and torque.
Airflow produces models that provide substantial ram and cold air induction effect and also models that provide ram effect only.

How does it work
Air is taken in at roof level where the air is less disturbed, contains less contaminants from the road and traffic conditions and is cooler than air from the engine bay or at ground level .

Why do we need more air?
Your engine needs air and fuel to make it work.
More air and oxygen going into the engine means more efficient combustion.
When the air is taken from under the bonnet / hood or the wheel arch the air is hotter than the air that is collected by a snorkel at roof level. The hotter the air, the less available oxygen there is for efficient combustion.

Modern vehicles have an engine management system that controls and measures the input and when to apply it, therefore an increase in cooler air inflow
will result in more power and torque.

Cyclone air ram operation
Air passing into an air ram creates a cyclonic effect which separates out the majority of the contaminants.

As the air swirls, the heavier air particles move out where they hit the vertical ribs which slow the particles down. Then with the action of the air, gravity and the ram- effect the particles are pushed out the four slots in the air ram.
The finer particles are removed by the vehicle air filter.

Not all air rams are equal in performance.
In general air rams need an open face preferably without a screen (which deflects airflow).
The ratio of the open face of the air ram to outlet aperture should be a minimum of 1.4:1 (Less than this ratio and there will be insufficient cyclone action to separate the contaminants out effectively)
Approximately 30% of the incoming airflow (above 25kph / 15mph) is used in the separation process.
Airflow uses a minimum of 1.4:1 for the 3” air ram, 1.7:1 for the 3.5” air ram
and 2:1 for the cold air induction air ram
A vertical cylinder section is incorporated for the cyclone separation to occur, with the aid of gravity and the air flow hitting against the separator ribs to separate the foreign material out.

Any deflection of the incoming airflow can dramatically affect the efficiency and the output.
This can be caused by:
1- Close proximity to a bonnet / hood
2-A foil / curved top on the air ram
3- Turning the air ram away from the direction of travel
4-Where the air ram design makes the air go back on itself at an angle greater than 100`
In the case of the air ram being turned away from the direction of travel the result is lessening of the positive pressure that is desirable. In the extreme a vacuum is caused (i.e. turning the air ram backwards which may cause engine damage.)
Incorrect design of the air ram can cause excessive induction noise, lack of separation, air blocking by vortex of the air at various speeds. This air blocking will limit airflow. This is a common occurrence where the design / look is put above the functionality of the air ram

Other types of induction into the snorkel induction tube / manifold.
Where the intake is moulded into the body of the snorkel (generally for design considerations) provide limited if any separation at all of the air.
Some cases where the snorkel intake is perpendicular to the direction of travel
This will cause a net vacuum at certain speeds.

Now the air has gone through the air ram and the heavy particles have been removed
The air is travelling in a straight line and is slowing down as it comes into a larger volume area (in the case of cold air induction models). This will cut down the swirling effect caused by the air ram. This in turn reduces the friction loss.
In the case of a non-induction tube type, air passes down to the outlet, where it is directed, with under bonnet tubing and ducting, into the air box.
This will still increase efficiency and performance, but not to the extent of a cold air induction type.

Air cleaner types
Cyclone air cleaners are the most effective in this application with flat air cleaners
being the least effective.
Airflow is releasing a parabolic cyclone air cleaner to match the cold air induction
snorkel now released.
This combination will give a dramatic improvement in performance and efficiency
across the power range of the motor.
The snorkel on its own can only deliver these improvement in the mid and lower rev range.
Where fitted in conjunction with a flat air cleaner element the improvements are in the low rev range only.

Use of Cyclone Separator in harsh conditions
Where the environmental conditions are such that vision is impaired by dust, rain snow or bugs a cyclone separator-non ram type-should be used.
This will not damage the engine duct and flow restrictions. The use of this type of separator will however reduce performance and economy.

Photo Gallery

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