Supercharged Vs. Turbocharged

Supercharged vs. Turbocharged

In the world of high performance engine parts there is probably no other topic

more debated than superchargers vs. turbochargers. In a fast paced world of automotive

ingenuity, both of these products prevail in horsepower production. Compared to other

possible engine modifications, these modifications remain on the top of the list for

creating power. Many different things need to considered when comparing these two

modifications, such as how they work their cost, fuel economy, durability, and generated

horsepower.

Both superchargers and turbochargers are forced induction systems and thus have

the same objective - to compress air and force more air molecules into the engine's

combustion chambers with more pressure than would normally be allowed at atmospheric

pressure here on Earth (14.7 psi at sea level). The benefit of forcing more air molecules

into the combustion chambers is that it allows your engine to burn more fuel per power

stroke. With an internal combustion engine, burning more fuel means that you convert

more fuel into energy and power. For this reason, supercharged and turbocharged engines

normally produce 40% to 100%+ more power (depending on the amount of boost). Boost is any pressure above atmospheric pressure in the intake manifold. When there is more air pressure in the intake manifold that means that there can be more fuel pressure as well. The higher pressure in the combustion chamber means that the

explosion used to move the pistons up and down is greater however this pressure has to resist combustion in order to achieve

more energy from the power stroke. A resistance to combustion is achieve

d through the type of gasoline used. There are uasually three different types of gasoline avaible at most gas stations and their resistance to combustion is represented by the octaine number shown at the pump, for instance 87, 89, and 92. The higher the number, the higher the resistance to combustion.

The cost of supercharger or a turbocharger system for a specific engine is

approximately the same, so cost is generally not a factor. If one is interested in purchasing a super of turbo charger, they should expect to spend approximately 2,500 dollars for a quality product. There are companies that offer these parts for as little as 1,500 dollars, however the reduced price comes with a cost not in a dollar amount. One thing that should be considered is that you get what you pay for. With a reduced price you will usually get reduced overall performance gains as well as reduced reliability and durability. On top of the cost for the part there is also a cost for installation. A person can install a turbo or supercharger for almost nothing if they are knowledgeable of such a process. For those who plan on installing such a part by themselves they should be aware that most all manufacturer warranties will be void, where as an auto shop will usually guarantee there work against defects that could potentially destroy the product due to improper installation. Most part manufacturers require that their product is installed by a certified mechanic in order to insure quality control and to qualify for warranty.

As far as fuel economy is concerned, it should not be a concern. When a person has installed a modification that adds anywhere from 40% to 100% of an engines original power, there will be a significant loss in fuel economy. A driver can still limit gas consumption depending on how often he or she uses unnecessary power.

A supercharger is mounted to the engine and is driven by a pulley that is inline

with the engine crank (or accessory) belt. Air is drawn into the supercharger and

compressed by either an impeller (centrifugal-style supercharger), twin rotating screws

(screw-type supercharger), or counter-rotating rotors (roots-type supercharger). The air is

then discharged into the engine's intake. Faster crank speed (more engine rpm) spins the

supercharger faster and allows the supercharger to produce more boost (normally 6 to 9

psi for a street vehicle). Typical peak operating speeds for a supercharger are around

15,000 rpm (screw-type and roots style superchargers) and 40,000 rpm (centrifugal-style

superchargers).

A turbocharger operates in much the same way as a centrifugal (internal impeller)

supercharger, except it is not driven by pulleys and belts attached to the engine's crank. A

turbo is instead driven by exhaust gasses that have been expelled by the engine and are

traveling through the exhaust manifold. The exhaust gas flows through one half of the

turbocharger's turbine, which drives the impeller that compresses the air. Typical

operating speeds of a turbocharger are between 75,000 and 150,000 rpm.

A lag or delay, is perhaps the biggest advantage that the supercharger enjoys