Automotive Engine Performance (980 views)
Automotive Engine Performance
All gasoline cars operate on the same basic principals, so it's easy to gain a general knowledge about what engine performance is all about. A few key factors to consider when researching the performance of a new car:
Engine performance all starts here. As the air flows into the engine it is mixed with fuel and burned to make power. Intakes with fewer restrictions will allow an engine to make more power. This is because restrictions in the intake path slow the air down before it reaches the engine, and reduce the amount of air that the engine can pull in at any given point in time.
Many modern engines have advanced modifications that increase performance by tuning the way the engine works in different conditions. Systems like Honda's popular i-VTEC system (intelligent Variable Timing Electronic Control) change the timing of the valves--the mechanism that controls the intake of air and the release of exhaust in your engine. By using different valve timing at different RPM (Rotations Per Minute, or speed your engine is working at) this allows your cars engine to work better in a variety of different conditions. This equals out to more power.
The compression ratio of your engine refers to how much the pistons compress the air that comes into the cylinders. High performance cars tend to have higher compression ratios. This allows the car to produce more power, but the downside of this is that cars with higher compression ratios usually require premium fuel which is more expensive.
Turbochargers and Superchargers
Turbochargers and superchargers are basically compressors that pressurize the air coming into the engine. This allows the engine to mix more air with fuel which can result in a drastic increase in overall power output. More and more cars are hitting the market equipped with turbocharged and supercharged motors. However converting a conventional engine to a forced induction setup is a very involved and costly process.
The last step in the process. Like the intake, reducing restriction in the exhaust almost always results in more power. Cars with performance exhaust system optimize the exhaust flow to have as little backpressure as possible. This allows the engine to expel the waste fumes as quickly as possible so it can burn more fuel faster. Performance exhaust systems usually use high-flow mufflers which tend to be louder than stock equipment.
There are a few advantages to knowing these basic principals that govern the performance of your car's engine. Not only can you be a smarter consumer, but you can also have a better appreciation of what is going on under the hood when you press on the gas pedal.