There are three main types of superchargers, the roots, centrifugal and twin screw superchargers all with their advantages
and disadvantages.
There are common attributes to all superchargers such as the parasitic effect on the engine because they
are belt driven from the crankshaft but there are some differences between the three.
Centrifugal
This type is closest in design to a turbocharger. The air compressor is a fan inside a
spiral shaped casing with a hole in the center and another hole at the end of the spiral.
The air usually enters at the center of the fan, compressed by the fan as it spins and exits at what would be the opening of
the spiral.
Centrifugal superchargers are compact, simple to install, flexible in placement along the intake system and in the engine bay
and it does not heat the incoming air much so usually does not need an intercooler.
The disadvantages are that centrifugal superchargers are not great for low RPM boost but have plenty of high RPM boost and they
usually require engine oil.
Roots
This type has two long (three prong) lobes that are aligned alongside each other inside a long casing with openings at the top
and bottom.
As the lobes spin they pull air from the top and send it out at the bottom where it is compressed in the intake manifold.
Roots superchargers were the first type of supercharger. They are fairly inexpensive, is great for both low and high RPM boost,
and does not require engine oil.
The disadvantages are that the root supercharger is a large and heavy, It has to be mounted after the throttle body and is usually
above the engine. There is also plenty heat in the incoming air and usually needs an intercooler.
Twin Screw
This type is similar to the roots supercharger but has two rotating screws instead of lobes in a long casing with holes at the
top and bottom.
The air enters from the top at the front and is forced along the length of the screws and is compressed at the back as the spacing
are smaller then it exits at the underside at the rear of the casing.
Twin screw superchargers are great for low RPM boost and good for high RPM boost, does not require engine oil and it does not heat the
incoming air much so usually does not need an intercooler.
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The disadvantages are that the root supercharger is an expensive supercharger, is complicated to install and has to be mounted
after the throttle body.
All three superchargers have some common attributes such as instant boost when you press the accelerator even if that boost is low
and the most complicated system would be simple compared to most turbos.
Whichever supercharger you or any marque decides to use on an engine will depend on your preference and your intended outcome for the
overall performance of the vehicle.
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