Dinan Semi-Open Cold Air Intake - BMW B46/B48 2017-2021

The Dinan Semi-Open Cold Air Intake for the B46/B48 four-cylinder BMWs adds an auditory port for a sportier note while flowing more air than the factory design. A larger airbox and filter element raise filter area 34% to 102.1 square inches, and a carbon fiber intake tube removes the factory baffling and Helmholtz chamber that create turbulence, freeing airflow and intake sound. An injection-molded air mass meter housing over 20% larger than stock and an airbox 30% larger help the engine breathe, yielding 6 HP and 6 lb-ft at 5000 RPM on an otherwise stock car.

Specifications

Documents: Installation Instructions (PDF)

This part fits:

Shipping

• In-stock orders placed before 3 PM EST ship the same day — everything else ships within 24 hours.
• Standard, expedited, and overnight options at checkout.
• Oversized items ship by freight and take longer.
• Backordered items ship as soon as stock lands — contact us for lead times.
• International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.

Returns

• 30-day returns on new, uninstalled items in original packaging with all hardware.
• Standard returns: 8% restocking fee, buyer pays return shipping. Both waived if the item is defective or we made the error.
• Installed or used parts can’t be returned — confirm fitment before you install.
• Special orders and custom items are final sale.
• Email us for return authorization before shipping anything back.

Full details: Shipping Policy · Refund Policy