while limiting noise.
1Fresh-air ducts
Fresh-air ducts serve as the entryway to the intake channel that routes air to the engine. They are injection molded and made primarily of polypropylene. Sometimes fresh-air ducts are welded to resonance chambers to produce a single part.
2Resonance chambers
Resonance chambers are integrated into the intake channels that route air to the engine in order to create branches in the channel. These parts function to cancel out intake noise by causing sound to resonate. They are fabricated using techniques including welding and blow molding, and made primarily of polypropylene.
3Rubber hoses
Rubber hoses are integrated into the intake channels that route air to the engine. These parts feature a characteristic bellows shape so that they can absorb vibration from the engine. They are injection molded and made primarily of oil-resistant ethylene propylene rubber (EPDM).
4Pressure sub-tanks
Pressure sub-tanks are installed in the high-temperature, high-pressure channels that carry engine coolant. They hold reserve coolant to make up for coolant lost to volatilization and other causes. These parts also absorb volumetric expansion and contraction due to changes in the coolant’s temperature. They are injection molded and then welded, and made primarily of glass-reinforced polypropylene.