Blown or Boosted

Blown or Boosted

When asking the question which is better turbochargers (turbos) or superchargers (blowers), the results are close. Based on the individuals’ driving style and needs, he or she may want consider the benefits and the potential drawbacks of these two systems to decide which best suites each driver’s needs.

When looking comparing Turbochargers and Superchargers there are several factors to keep in mind: power curves, efficiency, reliability, upgradeability, and value. The car enthusiast can be very particular about their own personal car and the way it performs. Both units exceed standard engines. They differ in the means by which they achieve those results. The units increase the pressure that goes into the engine. Normal or standard atmospheric pressure is about 15 pounds per square inch (psi) (Atmospheric Pressure). The job of the compressor common to both turbochargers and superchargers is to increase air pressure so that more air is forced into the cylinders. This is what car enthusiasts and racers call having a “blown” or “boosted” car. This increased air volume, or boost, is mixed with a proportionately increased fuel volume which, when burned in the combustion cycle, results in increased horsepower and torque production. However, this is where the similarities between the two types of systems end.

There are many differences between Turbos and Blowers. The first is the power curve. Superchargers build boost as rpm increases in a linear fashion, because they are belt driven from the engine crankshaft. This means that the supercharger is always on and achieves its maximum potential at higher rpm’s. The faster the engine is going, the faster the supercharger is turning. Turbochargers, on the other hand, are exhaust driven, and come up to speed very quickly. There are no belts or gears needed to activate the turbocharger. A long time racer and enthusiast Nick Ciccotello has a great understanding of cars, especially fast ones, and how they work. Nick does not have either unit on his latest machine, a 1971 Duster, but his future plans include adding a turbocharger. Ciccotello says, “ A turbocharger is perfect for what I want to do with my car. I can go for a Sunday drive and still take her out to the quarter mile every other Thursday. The turbo give me power at the higher rpm’s where my car needs it.”

Another major difference between the two units is the fuel economy. Perfect Power is a website dedicated to giving information about engines, including both turbos and blowers. Similar to the air conditioner compressor found on most cars, superchargers require horsepower to turn them via a belt (or gears). They take a defined amount of engine power to operate (superchargers). This puts stress on the motor, and as a result, the fuel economy decreases. Since turbochargers are exhaust powered, they do not add any stress to the engine. In fact, even when under full throttle, a turbocharger system will not make any major changes to the fuel economy.

When comparing reliability, a good rule to follow is that the more parts an instrument has, the more likely it is to break. The supercharger is not as reliable for a daily driving car. This is because there are many more moving parts on a supercharger. The supercharger design calls for belts and internal gears; and under high stress, these parts have been known to fail. Some of the serious problems include: crankshaft, bearing, and engine damage caused by belt tension forces on the crankshaft. Turbochargers only have one moving part, the compressor/turbine wheel assembly. The simplicity of the turbocharger makes it less prone to mechanical problems. Turbochargers have no belt and no direct mechanical connection to the crankshaft,