The paper is focused on possibilities to increase low or medium speed torque developed by a twin turbocharged engine, under full load operation. Sequential operation mode is analyzed from the point of view of compressor and possibilities to control transition area. A modality to reduce actual technological complications for a sequential turbocharger operation (STO) is presented by the proposal of a new simplified configuration and a new binary Controlled Blow-off Valve (CBV). More, a new turbocharger topology schema, able to operate in series or parallel connection of the compressors (SPCO) is presented. Comparison with the sequential turbocharger operation mode (STO) reveals the SPCO's mechanism, which can increase in a decisive way the low, and medium speed torque, increase turbochargers' life and simplify the transition operation mode. Solutions presented for a V6 spark ignition engine may be used without any hesitation for all twin turbo engines, including diesel.