do88 Cold Air Intake System - BMW B46/B48 (G20/G21) 2018-2026

This is do88's fully sealed intake system for the B46 and B48 four cylinder in the G20 and G21. The factory airbox is replaced by a fully enclosed 7 inch airbox with a heat shield and a secondary air feed, which matters because the intake sits directly alongside the exhaust manifold and heat soaks quickly. In place of the stock intake hose do88 fit a 102mm (4 in) mandrel bent aluminium pipe joined by a custom silicone hose, and a large 105mm cotton gauze filter that is washable and reusable. do88 measure a 23% airflow increase over the factory intake. The filter ships without oil, so cotton filter oil is recommended for dusty conditions.

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