Turbocharger/ supercharger vs naturally aspirated engine

Which is the best?

3y ago

106.9K

Before I begin, I would just like to say that this is extremely technical so for this might be boring for some people and also, If I get anything wrong please let me know and I apologise for any mistakes.

The turbocharger

A turbocharger is a turbine-driven forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra air into the combustion chamber. This improvement over a naturally-aspirated engine's power output is due to the fact that the compressor can force more air—and proportionately more fuel—into the combustion chamber than atmospheric pressure alone.

Turbochargers were once known as Turbosuperchargers when all forced induction devices were classified as superchargers. Nowadays the term "supercharger" is usually applied only to mechanically driven forced induction devices.

An example of a Turbocharged Car.

An example of a Turbocharged Car.

Heat is a major drawback of turbocharged cars, since the exhaust gases are extremely hot and can cause the engine to overheat. This can be combated by sending the exhaust gases through an intercooler, which is like a small radiator, which helps release some of that heat before the gases reach the engine. If the engine is outfitted with only one large turbocharger, power delivery from it can be delayed as the turbocharger takes time to spool up, which is called turbo lag. This can be overcome through biturbo or twin turbo systems that use more than one turbocharger and virtually eliminate turbo lag.

The supercharger

2015 Dodge Challenger SRT Hellcat

2015 Dodge Challenger SRT Hellcat

You can sense that the turbocharger and supercharger and mutual friends, and aren't really opposing each other. It's really Turbochargers & Superchargers vs. Naturally Aspirated Engines. Superchargers are like air compressors. Instead of drawing the gases from the car’s exhaust system they draw in fresh air and compress it before sending the air to the engine’s intake manifold. Superchargers in general aren’t able to produce as dramatic of power gains as turbochargers, but they don’t have a lag like turbos and they don’t struggle with heat issues. They also produce excellent power delivery at lower RPMs. Superchargers can produce an annoying whining noise when they’re operating. Depending on a supercharger’s setup, it can cause idle drop for the engine.

Naturally aspirated engines

A Naturally Aspirated Ferrari V12 Engine

A Naturally Aspirated Ferrari V12 Engine

Naturally aspirated engines draw air into the engine through an air intake, which depends on creating a vacuum to feed air into the engine’s intake manifold as needed. The only way to increase airflow to a naturally aspirated engine is to either replace the stock air filter with one that is less restrictive or to install a high-flow aftermarket air intake. The benefit of a naturally aspirated engine is that they are in general more reliable than forced induction engines, or engines that rely on a turbo or supercharger. The big drawback is that to have a high-output naturally aspirated car usually means having a large, heavy and petrol guzzling engine.

Twincharger

Now I'm guessing most people reading this article have not heard of a Twincharger. Simply, A twin-charged engines utilize both a supercharger as well as a turbocharger. It is an older technology that is seeing a sort of resurgence in new cars. Current engine trends are leading automotive developers to revisit the idea of twin-charged engines to increase performance while keeping the engine compact and efficient. The best way to gain this performance is to force induction by way of either a supercharger or turbocharger. The problem is that each of them greatly increases both fuel consumption and emissions.

A Twin-Charged Car

A Twin-Charged Car

Twin-charged engines try to overcome these issues by running both kinds of forced induction systems in tandem. The supercharger takes responsibility for the low end where it is most effective, engaging from idle speed. It keeps spinning until it is within the effective operating range for the turbocharger to take over. The turbocharger then takes over at higher revs where it works best.

Which is the best?

Well this is just a matter of opinion. Scientifically, there is no correct answer, the turbocharger is taking over the market yet some car companies like Aston Martin stay with the Naturally Aspirated Engine, saying that the car is more pure and nicer to drive. They may have a point. The supercharger has been forgotten in Europe and is only really used in the US, and the Twin-Charger may produce the most break-horse-power (as you would expect) but it does add a significant amount of weight and money.

Feel free to say which is the best and why in the comments. Adios!

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Comments (17)

  • Normally aspirated engines will consume the same amount of fuel as a turbocharged or supercharged engine of the same power, while making that power.

    Typically, power is a result of the increase in fuel added to the engine. More fuel = bigger bang, but more fuel also requires more air, and vice versa. Increase the amount of air via forced induction of any kind and you must also increase the fuel.

    The efficiency of a turbo motor comes when the turbo isn't spooling, and therefore is not creating any additional boost or power. Essentially, the reason most modern turbo engines produce such high efficiency numbers is because they are intentionally underpowered until they start to spool at higher RPMs. This makes your off the line power not so great (in most turbo cars).

      3 years ago
    • But in order for a NA engine to suck the same amount of air, it needs to rev faster, which increase mechanical losses, or having a larger displacement, which will add weight and increase fuel consumption.

        2 years ago
  • When you compress anything it tends to get hot. That is how diesels get away without using spark plugs. Which is why intercoolers are used in most forced induction applications. It has nothing to do with cooling exhaust gases down. The other thing this article fails to mention are the various types of superchargers. You have positive displacement and centrifugal superchargers. Positive displacement superchargers tend to have very strong mid to high rpm power. Centrifugal superchargers are essentially belt driven turbochargers. They don't see the same peak numbers as turbos due to engine power is required to spin the compressor.

      3 years ago
  • Turbochargers are *powered* be exhaust gasses but still draw in cold air from outside. In addition the air is pushed through the intercooler, not the exhaust gasses. Probably best to understand the mechanics of forced induction before writing articles about them.

      3 years ago
  • Is That The 1970 Dodge Charger R/T from Fast And Furious?

      3 years ago
  • Personally, I prefer Supercharger to Turbocharger but Naturally Aspirated Rules them all

      3 years ago

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