Why Does Smooth Exhaust Cause Low-End Torque Loss?

[DiCaroline]

Reasons for low-end torque loss: Aftermarket exhaust modifications with increased pipe diameter enhance acceleration but reduce backpressure, leading to low-end torque loss. Additional details: 1. Aftermarket exhaust impacts backpressure, affecting "valve overlap." At low engine speeds, exhaust gases are expelled faster, carrying away unburned fuel-air mixture. The engine then uses fresh fuel, causing low-end torque loss. This modification primarily influences valve overlap principles. 2. Passive valves installed inside mufflers or connecting pipes consist of a spring and flap. At low RPMs when exhaust flow is weak, the spring keeps the flap closed, increasing backpressure. 3. Active valves mounted on tailpipes use motors for operation, offering greater convenience at higher cost.