Turbo & Superchargers

Turbo and Superchargers are one of the most effective ways you can increase your horsepower and torque. The difference between the two can be confusing,here you'll get a basic understanding. The primary difference between a turbo and a supercharger is one is driven by pressurized exhaust gases (turbo) and one is directly driven by the engine itself. Some will tell you that a turbocharger is the way to go and others will say a supercharger is what you want. With this information,you should be able to understand which would work best for your particular application.
We'll cover the turbocharger first.
   The turbo is made up of an air intake,a compressor housing (houses the shaft and bearing assembly), and an exhaust turbine. Turbo's are driven by exhaust gases passing through the compressor housing thereby causing the turbine to spin. The turbine connects to a shaft assembly which in turn is connected to the compressor impeller. The compressor impeller is connected the the incoming air inlet. What happens is the air is pulled in faster and compressed more as the impeller increases in speed and forcing more air into the engine. Now,this is what makes the turbo more efficient than the supercharger. As the turbine and compressor blades revolutions increase,it does two things. First it increases the amount of negative pressure inside the exhaust system which helps with scavenging and in effect "rips the exhaust gases out of the chamber this help to create negative pressure inside the compression chamber so when the intake valve opens it effectively "rips" the pressurized air fuel charge into the cylinder. Second,the compressor has pressurized the air fuel charge on the intake side that when the intake valve opens, to mixture flows into the cylinder more effectively as a result of the negative pressure inside the compression chamber and the pressure of the charge in the intake runner. So the faster you spin the turbo the more power,in theory.

 There is a law of diminishing returns that comes into effect here. Now,that is an absolute that you can't get away from not matter what. However,you can manipulate it to a certain extent. When you compress air,it is effected by friction more and creates more heat. Heat is only good to a certain extent when it comes to an internal combustion engine. If you have too much heat going into the engine then you can get detonation, yes that detonation! It craters engines if it's not dealt with in time. installing an after-cooler or inter-cooler between the turbo and the intake manifold is the most effective way to cool the air charge. Not to mention that since engines like cold air because it is smaller and therefor you can get more cold air into and certain space than warm air. So using an inter-cooler of after-cooler,you don't have to have your turbo wound up to force more air in when you can in effect do the same at lower turbo speeds and cold air.


  One of the advantages of a turbo over a supercharger is fuel economy, this is due to the fact that a turbocharger has to pressure up in order to have any effect on the intake charger. It also has the advantage at higher engine rpm because it can spin up very fast. Turbocharged engines are more durable as well. This is because it does not increase the thrust load on the bottom end bearing of the engine at low rpm. Turbos are also quieter than superchargers but, you are I both know that if your here reading this noise is not your primary concern.
 
  There are some creative guys out there putting multiple turbo set ups on engines. Do your homework if you decide to go with a turbo on your engine. If done right it is the most efficient way to increase power. Now if efficiency is not your main concern and you want seat of your pants gut wrenching torque right off idle then supercharging is the way to go.
 
   A supercharger effectively "rams" the air fuel charge into the engine. They are directly driven by either a belt system or gear system right from the engine. Where as with the turbo with basically one style,superchargers have designs like a "roots" and "centrifugal". A roots type blower pulls air through the carb or throttle body and a centrifugal supercharger forces air through the carb or throttle body. Both systems require additional fuel,a free flowing exhaust and an air intake system that allows for at least 6-9 psi of boost. You'll want a supercharger that gives an extra 5-7 psi of boost if you plan on using it for the street. Anything more requires a lot of engine work and is not really all that streetable.

  You can change and modify boost levels with different pulley sized. As with the turbo,an inter-cooler or after-cooler can really effect how your engine responds to supercharging. You can get the same power from 5 psi of cold air and 8 psi of hot air. (That is just an example,you would have to do the math yourself for your application and the level of modification of the engine). Some supercharger kits will come with aftermarket ignition control systems. This goes a long way to controlling detonation. If you have ever watched a blower explode you know why you want to control detonation as match as possible. I'm not saying that this will happen,I'm just using it as a reference to what happens inside a combustion chamber when detonation happens. There are a lot of supercharging kits that come with after-coolers and inter-coolers that install with the kit.