System and method for controlling the transient torque output of a variable displacement internal combustion engine

A system for controlling the torque output of a multicylinder, variable displacement, spark-ignited, fuel injected automotive internal combustion engine coupled to an automatic transmission including a torque converter, comprising:

• a spark timing controller;
• a throttle controller for positioning an intake air throttle;
• an engine cylinder operator means for deactivating and reactivating at least some of said cylinders;
• a bypass clutch associated with said torque converter, for controlling the degree of lockup of the torque converter;
• and
• a controller having a processor which selects a number of cylinders for operation and operates said spark timing controller, said throttle controller, said cylinder operator means, and said bypass clutch such that during transitions from operation with a first number of activated cylinders to operation with a second number of activated cylinders, the processor will alter a spark advance, control the amount of air entering the engine cylinders, and control the bypass clutch such that a torque transmitting capacity of the torque converter is at least partially reduced.