two-stage turbocharger (bi-turbo) Cutaway are: both turbochargers, control flaps and the fresh-air valve. The turbines and throttle valves can be moved. Exhaust air, fresh air and oil channels are accentuated in colour. description ordernumber 1327 see also: model board: two-wheel technique distributor-type fuel-injection pump with charging-pressure control cylinder head with swirl chamber Electric turbocharger (e-booster)