The B58 is one of the best engines BMW has ever built, and it responds to air like few others. The factory airbox is quiet, sealed and sized for a compromise. Give it room to breathe and you feel it the next time you lean on the throttle, and you hear it too.
The Dinan Carbon Fiber Cold Air Intake for the BMW G20 M340i, G22 M440i and G42 M240i flows 58% more air than the stock system. It is not just a new lid. Dinan redesigned the entire lower airbox to use every bit of available space, then fit a custom filter with 40% more area than the factory element. On a stock car, Dinan measured peak gains of 9 WHP at 6500 RPM and 8 lb-ft at 6000 RPM.
How the Dinan Carbon Fiber Cold Air Intake Stays Cool
More air only helps if it is cool air. Dinan's semi-open design adds secondary inlets, and it tested a range of opening shapes and sizes across varied driving conditions to make sure the extra openings did not raise intake temperatures. The filter grows from 82 sq in to 115 sq in, so the engine pulls through a bigger, less restrictive path.
The box is real carbon fiber, not a vinyl wrap or hydro-dipped plastic. It also works with or without the factory strut bracing, so you do not have to choose between the intake and the chassis stiffness your car came with.
Dinan Cold Air Intake Install and Legal Status
This is a one-hour bolt-on with no cutting and no tune required. The gains above were measured on a stock car. Before you order, know this: it is legal under EPA's Tampering Policy dated November 23, 2020, but it is not legal for sale or use in the State of California. CARB testing is pending and no Executive Order number has been issued. Dinan part number D760-0058. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Carbon fiber intake box with lid
- Custom high-flow air filter
- Installation hardware
Key Features
- 58% more airflow than the stock system, per Dinan
- Dinan dyno result on a stock car: up to 9 WHP at 6500 RPM and 8 lb-ft at 6000 RPM
- Full lower airbox redesign, not just a new lid
- 40% more filter area: 115 sq in vs 82 sq in stock
- Semi-open design with secondary inlets tested for intake temperature
- Real carbon fiber construction, not a wrap or overlay
- Works with or without factory bracing
- Bolt-on install, about 1 hour, no tune required
Vehicle Fitment
Fits the following B58-powered BMW models:
- BMW M340i / G20 Sedan (2020-2026): M340i, M340i xDrive
- BMW M440i / G22 Coupe (2021-2026): M440i, M440i xDrive
- BMW M440i / G23 Convertible (2021-2026): M440i, M440i xDrive
- BMW M440i / G26 Gran Coupe (2022-2026): M440i, M440i xDrive
- BMW M240i / G42 Coupe (2022-2026): M240i, M240i xDrive
Installation Notes
Most owners with basic hand tools can do this in about an hour. Work on a cool engine and follow the Dinan instructions included with the kit.
- Let the engine cool completely and remove the engine cover if fitted.
- Unclip the factory airbox lid, loosen the clamps and remove the complete factory airbox.
- Install the Dinan lower box and filter in the factory location.
- Fit the carbon lid and secure every clamp with the supplied hardware.
- Start the engine and confirm all connections are tight with no warning lights.
