Turbo Lag

Turbo lag is the delay between a driver pressing the throttle and the turbocharger delivering full boost pressure. When a driver lifts off the throttle (e.g., for a corner), the turbocharger slows down. When the driver presses the throttle again, the turbocharger must spin back up to operating speed before it can deliver full boost — this takes a fraction of a second, during which the engine produces less power than expected. Turbo lag was a significant problem in the original turbo era (1977-1988) and in the early years of the current hybrid era (2014-2015). The MGU-H (Motor Generator Unit - Heat) in modern F1 power units virtually eliminates turbo lag by using electrical energy to spin the turbocharger instantly.

Turbo lag was a major challenge in the original turbo era. The 1977-1988 turbo cars had significant lag, making them difficult to drive out of slow corners. The current hybrid power units use the MGU-H to eliminate turbo lag, making the cars much more driveable.