S (stall stage): Within this point the turbine velocity is zero and the impeller is rotating; the effectiveness within the stall stage is minimal, about 50%, which means that 50 percent of the power coming in the motor is lost as a result of friction and dissipated as heat; at https://zionvbcca.pages10.com/5-simple-statements-about-torque-converter-clutch-explained-69586082