Exhaust element with heat exchanger

An exhaust element (10) of the type including a main exhaust pipe (16) and a bypass (18) mounted in parallel with the main pipe (16), which bypass (18) includes a heat exchanger (20), and in which are arranged moveable shutoff means (28) for shutting off the main pipe (16) and moveable means (30) for regulating the cross section offered for the gases to pass in the bypass (18);

• and characterized in that said exhaust element includes mechanical means (32) for synchronizing the moveable shutoff means (28) for shutting off the main pipe (16) and said moveable means (30) for regulating the cross section for the gases to pass in the bypass (18), under the control of a single actuating element and in that said mechanical synchronization means (32) are configured, under the control of the single actuating element, to provide successively, during an initial phase, the progressive increasing of the cross section offered for the gases to pass in the bypass (18), while keeping the main pipe (16) substantially shut off, and, during a later phase, the opening of the main pipe (16).