Technical Article – Turbo chargers vs. Super chargers
Turbo charge or super charge? That is the question most people ask themselves when they are looking to run forced induction setup on their engines. Depending on the application you are looking to use a forced induction motor for, will ultimately determine which of the two setups you should use. First let’s look into what a turbocharger and a supercharger are what they do. Then we will look at what the advantages and disadvantages are of both applications.
What is a Turbo charger? A turbocharger is a component that is bolted on to the motor and is driven by the exhaust gases of the engine. Turbos compress the air flowing into the engine, thus allowing more fuel to be added. Exhaust flow of the motor rotates a turbine inside the turbo, basically turning it into an air pump. Turbos allow more air and fuel to be ignited and burned inside the combustion chamber. They can allow up to 50% more horse power to be produced from the engine. A turbocharger can increase the horsepower output of the engine without increasing the weight of the vehicle dramatically. That will, in turn, increase the power to weight ratio of the vehicle allowing faster acceleration.
What is a Super charger? A supercharger is a component that is attached to the motor and is driven by a chain or a belt that is connected to the engines crankshaft. The belt or chain is connected to a pulley that is bolted to a drive gear. That drive gear turns the compressor gear. The compressor gear has a rotor. The purpose of the rotor is to draw in air. The air then gets compressed and is sent into the intake manifold. Superchargers compress air pressure similarly to a turbocharger. That allows more air to be forced into the motor. Superchargers can add up to a 46% increase in horsepower and also up to a 31% extra torque output reading. There are three different types of superchargers and they are listed as follows: rotary, centrifugal, and twin screw.
There are a few advantages to having a turbocharger. They can reduce emissions because they operate off of exhaust waste. So in turn, it basically recycles your exhaust gases. They are an affordable way to increase your engines top end power without having to build a new and bigger engine which would cost a lot of money to do. That would also increase the weight of the vehicle, resulting in slowing it down. They are generally easy to install and don’t require a lot of “pluming”. They use a lot of stock components and depending on how much boost you are running, they can be used on a stock engine safely up to 8 psi of boost.
Although turbochargers have many great advantages they also have a few disadvantages. They can significantly reduce your fuel economy. In addition to that putting a turbo charger on a car can be a bit of a challenge. They cost a bit of money and when you try to modify your engine to fit one it can often be a challenge to fit all of the tubing and wiring needed for it to operate properly. Smaller cars with less clearance can be an even bigger challenge to modify for fitment of a turbocharger and its components. They also require a heavier pressure of fuel supply. If you decide to run the boost higher than 8 psi, there are some modifications that need to be made. The fuel delivery system will need to be upgraded such as the fuel pump and the fuel injectors/carburetor. The radiator will need to be upgraded to cool the engine off from the increased heat that is now being supplied by the turbo. The spark plugs will need to be upgraded so they don’t melt from increased heat. The knock sensors will also need to be upgraded and an intercooler will need to be installed. You will also need to install a boost controller.
There are also advantages to having a supercharger. Superchargers can create power from lower end rpms because unlike a turbocharger, it does not require built up pressure from the exhaust system. It also does not have lag response from the throttle because it is driven directly from the crankshaft. The system is more reliable than a turbocharger because it is not under stress from heat like the turbo charger is. The rotary style supercharger does not require the use of an intercooler to make the air going into it more dense.
Superchargers also have a few disadvantages as well. The system has some limitations so it may not produce an equivalent amount of power like the turbocharger. The supercharger has to take some horse power away from the motor in order for it to operate. It also adds added strain to the motor, so the engine has to be strong enough to withstand the added strain produced by the supercharger. Superchargers also cost more to maintain and they require a higher octane gas to function properly and to avoid damage to the engine. The rotary supercharger requires more oil maintenance and operation is loud due to the whining noise from the rotors inside of the supercharger. The large size of the rotary style supercharger also causes a need for more hood clearance causing modifications to the vehicles hood to be made. The supercharger also generates more heat and consumes more fuel from the motor, reducing gas mileage. The centrifugal style commonly runs an intercooler and requires more “pluming” than other superchargers. Finally, the disadvantages of the twin screw supercharger is that they are expensive, they need exact tolerances for operation and they create a lot more noise.
In conclusion, turbochargers and superchargers are both great systems for forced induction. They both come with advantages and disadvantages. Ultimately it is the drivers decision on what he would like to use on his motor, but there are a lot of factors to consider before bolting one of these systems on to the motor.