Twin-turbo (Biturbo)

Parallel setups often give each bank of a V engine its own turbo. Sequential setups use a small turbo for quick response and a larger one for high power. Twin-scroll turbos are a different design that uses one turbo with a divided housing.

Exhaust gas drives each turbine, and valves or the engine layout decide which turbo is supplying boost at a given moment.

Diagnosing boost faults is more complex because there are more pipes, valves and actuators. Turbos need clean oil and a short idle after hard driving to protect their bearings.