Supercharger vs Turbo Charger – The Two Main Types of Forced Induction
Supercharger vs turbo charger is a debate that has been going on for years. Both a supercharger and a turbocharger are forced induction systems. But which is better? Let’s find out
In simple terms both a supercharger and a turbocharger charge or “force” more air into the engine effectively increasing the strength of combustion. They squeeze more power out of an engine when compared to natural aspiration. This, by squeezing more air into the engine instead of just letting the engine suck the air in. You can think of it as being force fed… but in a good way.
Which is better usually depends on the type of car. Some cars benefit more from a supercharger while others are better off with a turbo. It also might depend on which you like best when you’re talking about your car. For example, you might prefer saying “My little Honda Civic Type Rrrrrrr is Suuuuperchaaarrrrged!” Rrrrrrr! Or maybe, “My little Honda Civic Type Rrrrr has a big ‘ol Turrrrrbo!” See all the R’s? Wondering where “Type R” comes from? Where there you have it!
Blower what? Supercharger vs Turbocharger – Which is better?
For a supercharged car example see our Supercharged Subaru BRZ Review.
Joking aside, ease of installation, availability and price can have a big impact as to which might be better as well. Some types of cars, in their higher trims come with a factory supercharger (also known as a blower). Of course, on these types of cars, if you own one that doesn’t have forced induction, it’s relatively easy to add it. The car manufacturer already makes one for the car anyway. Aftermarket parts manufacturers will usually go that route as well and create their own units. Good examples are the Ford Mustang GT and the Chevrolet Corvette. Both Ford and Chevy make supercharged models of these cars (Shelby GT500 and Corvette ZR1). For this very reason it’s much more common to see aftermarket superchargers on these cars than you would turbos – even though there are plenty of people that put turbos on Mustangs and Corvettes.
…there are plenty of people that put turbos on Mustangs and Corvettes.
Same thing goes for turbochargers. Cars like the Mitsubishi Lancer Evolution, Subaru WRX Sti, Golf Gti Turbo and Porsche 911 Turbo come with factory turbochargers. What this means is that the same models in lower trims (non-turbo) are more likely to get aftermarket turbochargers than they are of getting a supercharger. For many cars like these, there’s not even an aftermarket supercharger available for them. Many times, aftermarket forced induction ends up being one or the other – but on rare occasions, both!
The turbo boost
Generally, in the supercharger vs turbocharger debate, you can squeeze a whole lot more power out of an engine with a turbo than you can with a supercharger. The reason for this is because a turbocharger is considerable more efficient. The fact is a turbo is actually a type of supercharger, however, it uses exhaust gases to spin a turbine that works the FI compressor (force induction compressor). This makes the turbocharger very efficient because it runs on otherwise wasted energy. However, the downside is that a turbocharger doesn’t work very well, or at all at lower RPMs. The turbine(s) needs to spool up and spin fast for the turbo to kick in. For that reason, not much happens at low RPMs. This is what is called turbo lag. Apart from that, turbos run on exhaust gas, which is hot. Add to that the fact that turbos spin at much higher RPMs than superchargers (upwards of 150,000 RPM) an intercooler system is needed to keep the system under control. Turbocharger systems are usually more complex and expensive to install than many superchargers. Many pipes are needed to feed the system along with oil lines and intercooler pipes.
…a turbo is actually a type of supercharger, however, it uses exhaust gases to spin a turbine…
In a car like the Mitsubishi Evolution X GSR with a stock turbo, you really don’t feel boost until you start winding the RPMs past 2,800. Go past 3,000 RPM and up and you really start feeling the turbo kick in. This can be a good and a bad thing. Yes, you can get more power out of turbo, but the turbo lag can get really annoying depending of course on the type of car. It’s much worse on some cars than it is on others. On the other hand, it’s really interesting, especially for passengers to suddenly feel that incredible surge of power the moment the turbo boost kicks in. Up to you what you like best.
Cars with twin turbos are very similar to cars with a single turbo. Twin turbochargers are generally used to counteract turbo lag. Instead of using one large turbocharger, the car is fitted with 2 small turbos that are designed to spool up much faster in turn reducing turbo lag times.
Supercharge this!
A supercharger is also known as a blower. It is generally less efficient than a turbo and you can usually get less power out of an engine with it than you would if it had a turbo. The supercharger bolts on to you engine in much the same way the alternator or AC compressor is installed on there. It’s powered with a belt just like the other engine components. This is the reason a supercharger is less efficient. It needs to be driven by the engine itself and adds load and therefore zaps the engine of some power. The reason you end up with power boost is because you gain a whole lot more power than what is zapped by the supercharger mechanism. Superchargers product a distinct “whine” type of sound as you accelerate. This might be something you’d like… or something you’d hate.
Even though a supercharger is less efficient than a turbo and provides less extra power, it does have many plusses. The biggest plus of a supercharger vs turbo is the lack of turbo lag. A supercharger will boost and provide extra power all the way down in the low RPM numbers effectively increasing the power band more evenly and doing away with lag. Also, superchargers doesn’t run on hot exhaust gasses and they don’t spin nearly as fast as a turbo. For this reason, keeping safe temperatures is much easier.
There are different types of superchargers and each offer various pros and cons:
Centrifugal Supercharger – Looks a lot like a turbo. It’s very efficient but provides the smallest amount of boost. Thanks to that however, it’s safer and less complicated to run than other types. It’s also generally no problem to cool. Compared to a turbo that spins at over 150,000 RPM, a centrifugal supercharger spins closer to 50,000 RPM.
Roots Supercharger – This is the one of most recognizable types of superchargers. It’s much bigger than a centrifugal supercharger. It works with two meshing roots or lobes that spin against each other to compress air and feed it into the intake manifold. They allow much more power and boost than a centrifugal supercharger. However, heat can be a problem and an intercooler system is often needed. Roots supercharger boost more than centrifugal superchargers but actually spin at much lower RPMs.
Twin Screw Supercharger – This type of supercharger is very similar to the roots type supercharger but it uses two large counter rotating screws instead of lobes. Screw superchargers have become hugely popular. The nice thing is that they are good middle ground between a centrifugal and a roots supercharger. They provide much more boost than a centrifugal supercharger and heat-buildup is much less than a roots supercharger. They are considerably more complicated to install than a centrifugal supercharger. A twin screw supercharger spins at more or less then same speeds as a roots supercharger; around 15,000 RPM.
Forced induction by country
Superchargers seem to be more popular in American cars while turbos are more common in Japanese cars and other imports. But things are changing and more car companies from many countries are now using both depending on the car model. A lot of it has to do with engines sizes as well. Japanese cars are famous for getting lots of power out of small engines. Think about it for second… I bet you can’t quickly come up with the name of a Japanese sports car with a V8 in it. Turbos in small V6 and I4 engines are great. You can get tons of power out of a small engine. American cars as well as many German and Italian cars are known for their large engines. Most powerful American cars run on V8’s. The Italians, Germans and even the English are known for everything from V8 to V12’s. These engines are already very powerful and a supercharger is a perfect fit for them.
To conclude
You’ve probably figured out by now that when you compare a supercharger vs a turbocharger, there is no clear winner. They both offer their own pros and cons. Which one is best really depends on the application and this varies greatly from car to car. It also varies a lot by your intended usage. Since cost of installation and availability also varies from car to car, a supercharger can be more expensive to run than a turbo on some cars and vice versa. Also, the benefits and downsides of each can be amplified from car to car. For example, you can run a good supercharger on a well-tuned Mazda MX5. By the same token, turbochargers are also very popular and successfully run on these cars. Other cars, are more inclined in either direction only.
