Storage battery tuning of engine air intake system

An engine compartment (10) of an automotive vehicle houses an internal combustion engine (12) having an air intake system (14). The engine compartment also contains a electrical system storage battery (24). A tray (28) has a bottom wall (32) and upright walls (38, 40) forming side-by-side compartments (34, 36) that are open at the top. Fasteners (58) fastening the tray bottom wall at a first (34) of the compartments in a hard mounting to underlying structure of the vehicle that is spaced from the engine. The battery is disposed on the bottom wall in the first compartment. A cap (46) closes the open top of a second (36) of the compartments that adjoins the first compartment and cooperates with the second compartment to form an air box (16). The hard mounting of the battery compartment to the underlying vehicle structure and the cantilevering of the air box to one side attenuates transmission of objectionable air intake noise and vibration frequencies through the vehicle structure.