Exhausts, Backpressure and Effects on Engine Performance

The mid pipes are the section of exhaust pipes that sit between the catalytic converter and the muffler. On vehicles that have two exhaust pipes, the mid pipes run parallel to each other. They often have a parallel pipe that connects the two sets of mid pipes together, or the mid pipes converge into a single pipe at one point. Either setup is designed to keep the backpressure consistent between the two pipes so the exhaust gases move out of the engine at the same rate among all of the cylinders. A difference in backpressure between the two mid pipes would result in unpredictable engine performance, causing the vehicle to accelerate slower.

The muffler is designed to literally muffle the sound of a vehicle’s exhaust system. Aftermarket mufflers come without many of the sound barriers found in stock systems, further reducing backpressure but making the exhaust louder. The exhaust pipe attached to the muffler is larger than on stock systems.

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