To limit power, all forced induction cars were fitted with a 34 mm diameter air restrictor before the turbocharger inlet, limiting the airflow to about 10 cubic meters per minute. The restriction was intended to limit power output to although some WRC engines were believed to produce around . Engine development did not focus on peak power output but towards producing a very wide powerband (or power curve). Typically, power output in excess of was available from 3000 rpm to the 7500 rpm maximum, with a peak of at around 5500 rpm. At 2000 rpm (the engine idle speed in "stage" mode) power output was slightly above .