Roots
vs. Centrifugal vs. Screw Type Supercharging
The most effective
performance enhancement that you will ever do to your car or truck is definitely
a supercharger. That is why it is very important that you choose the right
type of supercharger to get the right kind of power for the type of conditions
that you will put your vehicle through. This is a guide to help understand
it's not just about forcing more air down the throat of your motor. There
are different ways to get the air to the motor and these different ways create
different type of power curves.
Centrifugal
Type Supercharging
Centrifugal Supercharging compresses the air inside the case of the supercharger
using an impeller. Then, discharges the air out of a scroll to the motor.
This design is similar to turbo-charging except for centrifugal superchargers
don't use the exhaust to build pressure, they use a belt, driven by the crank
pulley to spin the impeller. Centrifugal supercharging is definitely one of
the more user-friendly ways to supercharge your motor. The ability to change
the impeller sizes and to spin the impeller at different speeds creates a
more inexpensive way to have flexibility in your power curve. Centrifugal
superchargers have become the standard for street use and light-duty racing
and far outsell all other types of superchargers.
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Recommended
Usage:
Street Use - Commercial Use - Road Racing - Drag Racing
Positive
Points:
1) Lots of Flexibility for Power Adjustments
2) Lower Discharge Temperatures
3) Great Reliability
4) Easy to install
Negative
Points:
1) Not as much power at low RPMs as Roots or Screw type superchargers
Manufacturer
Availability:
Paxton - Powerdyne - ProCharger - Vortech
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Vortech's
Centrifugal Type Supercharger
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Roots Type Supercharging
The Roots Type Supercharger is the first style supercharger that was ever
used and can be dated back to the 1880s when the Roots brothers designed it
as an air conveyor for mine shafts. Roots blowers act like air pumps (not
compressors), and In general, Roots blowers have a two or three lobe rotor
design, depending on the size of the case. Roots blowers will give you positive
pressure to your motor from just a crack of the throttle, and will give all
that they have to offer at full throttle no matter what the rpm of the motor.
Roots Type Superchargers may look awesome hanging out of the hood and are
great for those looking for drastic power increases at lower RPMs. Roots blowers
are also extremely reliable and require very little maintenance, which is
why Ford, GM, Mercedes, Jaguar, and Austin Martin have all featured Roots
blowers as original equipment on select high performance vehicles.
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Recommended
Usage:
Street Use - Towing - Extreme Drag Racing - Show Vehicles
Positive
Points:
1) Boost throughout the entire RPM range, right off of idle
2) Highest Potential for Gain (A must-have for all-out drag racing)
3) Excellent Reliability
4) Great Appearance & Stature (Most common supercharger type for show
vehicles)
Negative
Points:
1) Sometimes Violent Throttle Response
2) Lower boost ratings at higher RPMs
3) Higher Than Normal Discharge Temperatures
4) Lengthy installation times
Manufacturer
Availability:
Allen Engine Development - BDS - Magna Charger - B&M- Holley - Littlefield
- Mooneyham - Weiand
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Holley's
Roots Type Supercharger
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Screw Type Supercharging
Screw type superchargers are derived from the Roots type concept but with
vast improvements for street use. Although from the out side, screw type superchargers
may look a lot like Roots type superchargers, on the inside you will find
a twin-screw design that compresses air unlike Roots type superchargers which
pump the air into the motor. Screw type superchargers have an axial-flow design
that compresses the air as it moves between the screws to create positive
pressure without creating the heat that Roots type superchargers can create.
The Screw type supercharger's ability to produce a dramatic increase of power
from idle and through out the rest of the power curve make them a great choice
for heavy vehicles, towing or commercial use.
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Recommended
Usage:
Street Use - Towing - Road Racing - Drag Racing
Positive
Points:
1) Great Power at Low RPMs (Great for Towing)
3) Factory Fit & Appearance
4) Great Reliability
Negative
Points:
1) The Power Doesn't Keep Climbing in the High RPMs (Power curve is
very flat)
2) Challenging To Achieve High Boost Levels or CFMs
3) Lengthy installation times
Manufacturer
Availability:
Kenne Belle - Whipple
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Whipple's
Screw Type Supercharger
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