Ep 9. The Power of 2.5- vs. 3-Inch Exhaust

Engine Masters is a television show that explores the world of engines and how they work, with each episode taking on a new topic or challenge. In season 1 episode 9, titled "The Power of 2.5- vs. 3-Inch Exhaust," the show's hosts dive into the debate of exhaust pipe sizes and their impact on engine performance.

For this episode, the Engine Masters team sets out to answer the age-old question of whether a 2.5-inch or 3-inch exhaust system is better for engine performance. To do this, they test both sizes on a 440-cubic-inch big-block Mopar engine with a single four-barrel carburetor.

Before putting the engine to the test, the hosts provide some background on exhaust systems and their importance to engine performance. They explain that the exhaust system is responsible for expelling the gases created during the combustion process out of the engine and into the air. A properly designed and sized exhaust system can help improve engine performance by reducing back pressure and increasing airflow.

To test the different exhaust pipe sizes, the team uses a chassis dyno to measure the horsepower and torque produced by the engine with each exhaust system. They also use a wideband O2 sensor to measure the air-to-fuel ratio and ensure that the engine is running at the correct mixture.

The first test involves the 2.5-inch system, which is run on the engine to establish a baseline. The team then swaps out the 2.5-inch system for the 3-inch system and runs the engine again to determine whether the increased size provides any performance gains.

The results of the tests are surprising, as the team finds that the 2.5-inch system actually produces more horsepower and torque than the 3-inch system. The hosts discuss why this might be, citing the fact that the larger diameter of the 3-inch system may actually be slowing down the exhaust gases due to the increased volume of the pipe.

Despite the lack of performance gains with the 3-inch system, the team notes that there are situations where a larger exhaust system may be beneficial, such as with forced induction engines or high-revving engines that require more airflow. They also note that a properly sized exhaust system should be tailored to the specific engine and its intended use.

Overall, "The Power of 2.5- vs. 3-Inch Exhaust" is an informative and entertaining episode of Engine Masters that provides valuable insight into the world of engine performance and exhaust systems. It also serves as a reminder that there is no one-size-fits-all solution when it comes to building a high-performance engine, and that careful consideration must be given to each component.