The term describes a type of engine modification strategy, primarily within the automotive performance community. It signifies optimizing an internal combustion engine to achieve increased power output solely through naturally aspirated means. This involves modifications such as enhanced cylinder head porting, camshaft upgrades, increased compression ratios, and optimized intake and exhaust systems. An example would be a vehicle that originally produced 200 horsepower, subsequently modified with these techniques to produce 250 horsepower without the addition of forced induction.
The significance of this approach lies in its perceived purity and responsiveness. Engines built in this way are often viewed as offering a more linear and predictable power delivery, valued for its direct connection between the driver’s input and the engine’s response. Historically, it represents a traditional approach to engine tuning, predating the widespread adoption of turbocharging and supercharging. Enthusiasts often appreciate the challenge of maximizing performance through careful optimization of engine components and precise tuning.
