Installing a K&N air filter on a Harley Davidson Road King may potentially have some impact on the sound and performance of the motorcycle, but the extent of the change will depend on various factors.
Sound: Changing the air filter alone may not significantly alter the sound of the motorcycle. The exhaust system and mufflers have a more significant influence on the overall sound. However, the increased airflow from a K&N air filter might enhance the engine's intake noise slightly, giving it a slightly more aggressive tone.
Performance: A K&N air filter is designed to provide higher airflow compared to the stock air filter. This increased airflow can potentially improve the engine's efficiency and power output, though the actual gains may vary depending on the specific bike model, engine configuration, and other factors. It's worth noting that the performance improvement may not be substantial, especially if the bike's engine is already well-tuned from the factory.
When modifying any aspect of a motorcycle's intake or exhaust system, it's important to consider the overall balance and compatibility of the components. Simply adding an aftermarket air filter without addressing other areas, such as the exhaust system and fuel management, may not yield significant performance gains. It's advisable to consult with knowledgeable professionals or refer to reputable sources to understand the potential impact of specific modifications on your motorcycle model.