Turbocharger vs. Supercharger: What's The Difference?

Posted by JB Tools on 9th Sep 2016

Tired of having some grandmother’s in minivan beat you in drag races? You're going to need to spruce up your horsepower! But before you go splurge your life savings, retirement money, kids' college fund and inheritance on a new Bugatti Veyron, you might want to consider installing a horsepower booster instead. What we mean, of course, is putting in a supercharger or a turbocharger. Both of these devices will give your car a significant horsepower boost, helping you show grandma just what your car’s made of. Although conceptually similar, these two devices work differently, each with various benefits and downsides. Do you go for more horsepower right out of the gate, or lean more toward providing an efficient solution to your horsepower increase? That all depends on a few key details.

Supercharger vs Turbocharger: Similarities

It’s understandable to wonder about the difference between turbocharger and supercharger solutions. First, let’s take a look at what these two mechanical additions have in common. The best way to go about this is by answering one question: What powers your car? If you answered “gas”, you’re only partly correct. While it’s true that gas, diesel or whatever type of fuel you use to power your car is absolutely essential to turning your car from a hunk of metal to a fast moving speed demon, it’s the other component in the process that most car owners fail to recognize: air.

Engines operate by creating combustion. When fuel and air combine with high heat, a small explosion is created within the engine. This provides power and thrust. And this is where size makes a difference. Larger engines mean more room for combustion, meaning more power. Generally, this is why a larger vehicle requires a larger engine. A small engine will still create needed combustion, but without the ability to generate enough horsepower from larger explosions, a smaller engine is simply not going to move that vehicle very far very fast.

Turbochargers and superchargers capitalize on the energy your car is already producing in order to create additional horsepower. This is through a forced induction system. Forced induction systems use the energy of a gas-powered engine to create compressed air. This compressed air is pushed into the car’s intake system. The payoff? More power and, in the case of a turbocharger, much more efficiency.

Generally speaking, without a forced induction system, your car gets air simply through atmospheric pressure. This is why it’s harder to power a car at higher altitudes, or why your car’s fuel efficiency drops when you haven’t changed your filters recently. A higher concentration of oxygen pushed into the combustion chamber harder and with more density leads to more power. A forced induction system compresses air and pushes it into the engine. Think of it like blowing air into a fire. It will certainly burn with just the normal intake of air. But giving it more air will help it burn better and hotter.

When it comes deciding on a supercharger vs turbocharger, there are also similar advantages and disadvantages to using either system. Both will provide more horsepower. This is an obvious and immediate advantage. However, both systems will cause your engine to work harder, thus generating heat extra heat in the engine. And because most superchargers and turbochargers are aftermarket additions to a car, they often require an endless game of tuning and re-tuning of your engine.

Now to the good part!

What is a supercharger?

You’ve already learned that a supercharger is a type of forced induction system. But what is a supercharged engine, really? And how does a supercharger differ from a turbocharger? There are several key differences.

First, a supercharger will not be located in the same place. A supercharger is a belt-driven air compressor. So, like your car’s AC unit, the supercharger gets connected to your car’s crankshaft. The spinning of the belt powers the air compressor. That compressed air is fed directly into your engine's air intake. The result is an immediate boost to your car's horsepower. If you ever wonder why one car in a drag race takes off significantly faster, it's likely because that car is using a supercharger or a superior supercharger, or it simply has its supercharger more finely tuned.

Supercharger Pros and Cons

There are clear benefits to a supercharger. However, a supercharged engine also has some very noticeable disadvantages.

Pros	Cons
●Low RPM requirement	●Draws excess power from the engine due to connection to crankshaft
●Faster horsepower boost	●Will burn fuel faster
●Wider RPM range	●Less efficient due to drawing excess engine power
	●Best used on larger engines

What is a turbocharger?

Turbochargers are masters of efficiency. While they also provide compressed air, as a forced air induction system, their operation is noticeably different than what you’ll find with a supercharger. One of the key differences between a turbocharger and a supercharger is time. A turbocharger will take longer to spool, or start working, because of how it operates. It also has a more limited RPM range because of how it functions.

A turbocharger does not connect to your car’s crankshaft and is not belt-driven. Instead, the system is spun by taking in your car’s exhaust to spin a turbine. This is part of what makes a turbocharger more efficient. Instead of using more of your car’s power to operate, a turbocharger uses waste energy to operate, while feeding more power into your engine as a result. The exhaust moves through the turbo’s intake, spinning the turbine. The turbine powers the air compressor. The compressed air is directed through an air coolant system and then moves into your engine's air intake and combustion chamber, creating more horsepower.

Unlike a supercharger, a turbocharger won’t start up right when you first turn on the engine. Because the pressure from the exhaust needs to be high enough to not only spin the turbine but make it spin fast enough to create noticeable air compression, a turbocharger will almost never work at a low RPM. Turbochargers are best when the RPMs are high, as they can provide even more horsepower on the high end.

Turbocharger Pros and Cons

A turbocharger may be more efficient, but its location and operation style does lead to a few notable downsides.

Pros	Cons
●Much more energy efficient than a supercharger	●Can get extremely hot due to using exhaust
●Can provide more horsepower ultimately at higher speeds	●Requires coolant to work effectively
●Creates little extra load on engine power	●Can have a sometimes significant spool time or “drag” time before it begins working
●Utilizes waste energy to operate	●Will not work at low RPMs

What Forced Induction System to Choose

Now that you know the difference between a turbocharger and a supercharger, you may still be scratching your head a bit. Which one will really help you in the long run? If your goal really is to show granny who’s boss on the road, you’re probably going to want to install a supercharger. After all, you’ll have that thrill of getting an immediate horsepower boost and watching as her minivan fades away once the light turns green. But turbo vs supercharger efficiency is nothing to ignore. After all, what is a supercharged engine but a giant energy drain? Beating grandma to the next stoplight might give you a feeling of superiority, but it’s not for those who crave efficiency and a long-term horsepower boost.

If you really can’t decide, well, there’s always the option of twincharging. Either way, deciding between a supercharger vs turbocharger hopefully should not keep you up late on too many nights. It’s really a simple argument between quick power and overall energy efficiency.