Patent ID: 8447502

Claim:
An engine system, comprising, an engine with a first and second group of cylinders; a turbocharger; a variable cam timing mechanism including a first cam coupled to the first group of cylinders, and a second cam coupled to the second group of cylinders; and a controller with computer readable code carrying instructions for, in response to an occurrence of pre-ignition in a cylinder in the first group of cylinders, increasing a cylinder pre-ignition count; limiting an engine load of the first and/or second group of cylinders based on the pre-ignition count, the limiting including adjusting a cam timing to limit an engine load of the first group of cylinders more than the second group of cylinders when the pre-ignition count is greater than a threshold, and adjusting the cam timing to limit an engine load of the first group but not the second group when the pre-ignition count is smaller than the threshold; and enriching the cylinder based on the pre-ignition count.