What is naturally aspirated

The more air that enters into the combustion chambers of an engine, the more fuel can be added - creating bigger explosions and generating more power. As the vehicle increases speed, the rate at which air flows into the engine also increases, granting it the ability to produce the necessary power at higher speeds.

Naturally Aspirated engines tend to be of a larger displacement, as they lack the extra power provided by a forced induction system. They compensate for it by either increasing the number of cylinders or increasing their bore, resulting in a larger volume of space contained within the combustion chambers.

Forced Induction systems work to force more air into the engine than it would otherwise be able to take in, allowing the engine to generate even more power than it would normally under the same conditions. One of two systems is generally used; Superchargers or Turbochargers.

A Supercharger is a compressor mounted at the air intake point and runs directly off the engine via a belt or chain. Their advantage over Turbochargers is that they are always running, meaning there is no delay in the extra power being delivered. With the flow rate generated by them directly governed by the engine speed, it provides the required amount of airflow at all times.

The downside however, is because it does run directly off of the engine, some energy is lost powering it and the engine is less fuel efficient than it could be. Turbochargers have to be mounted further down in the engine, as they must also be connected to the exhaust system. The naturally aspirated motor uses only atmospheric pressure and vacuum in the inlets to fill the cylinders.

This engine differs from the force-fed engine which uses blowers to force more air into the cylinder than it is naturally possible. Hence, supercharged and turbocharged engines do not count as the naturally aspirated type of engines.

The naturally aspirated engine draws the air for combustion into the engine cylinders only by atmospheric pressure. It acts against a partial vacuum which the piston creates when it travels down towards the bottom dead center. This happens during the intake stroke in naturally aspirated cylinders. Due to a natural restriction in the engine's intake path which includes various inlets, a small drop in the pressure occurs as air draws in. Consequently, a naturally aspirated engine gets less air-charge inside the cylinder.

Therefore, it also affects the engine's maximum theoretical power output. NA on the other hand is simple thus is more reliable than a turbo because it has fewer parts that may fail. This makes the turbo a bit harder to maintain than NA engines. To be honest we all know where this is heading. The entire point of turbochargers is to add extra power to engines and they outperform NA in power by leaps and bounds.

They are able to generate more power from smaller engines than NA can from bigger engines. NA however not be left behind is seeing new technologies that allow it to boost its torque albeit not close to something like turbochargers.

Till we see more from Mazda turbos are more powerful than NA sometimes even when using a smaller engine. Quite frankly no, even though turbo is taking over the worlds automobile market some companies like Aston Martin and Mazda refuse to give up NA engines and are bringing new technology that can challenge the turbo.

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