The B58 was the engine that made the F-chassis cars special. Smooth, strong, and easy to tune. The factory intake does not let you hear much of it, though. BMW packed the intake tube with baffles and a resonance chamber for one reason: to keep the turbo sounds out of the cabin.
The Dinan Carbon Fiber Semi-Open Cold Air Intake for the B58 BMW M240i, 340i and 440i swaps that quiet, restrictive setup for a full carbon fiber airbox, a smooth intake tube and a larger filter. Dinan measured up to 15 HP and 13 lb-ft at 6000 RPM. The semi-open lid adds an auditory port, so you actually hear the turbo spool and breathe.
What the Dinan Semi-Open Cold Air Intake Changes
The airbox is 30% larger than stock, and the filter area grows from 76.3 to 102.1 square inches, 34% more surface for the turbo to pull through. The intake tube drops the factory baffling and the resonance chamber that create turbulence and cost power. The air mass meter housing is 8% larger. Less restriction means the turbo works less to make the same boost, and throttle response sharpens through the rev range.
This is 100% genuine carbon fiber, not a wrap or overlay on plastic. The semi-open lid is the difference between this part and Dinan's closed-box D760-0046: same flow hardware, more sound.
Dinan B58 Intake Legal Status and Fitment
Before you order: Dinan lists this intake as not legal for sale or use in the State of California. CARB testing for 50-state compliance is pending. Outside California it is legal under the EPA Tampering Policy. It fits the M240i, 340i and 440i across the F22, F23, F30, F32, F33, F34 and F36 bodies, and it is a one-hour bolt-on with no cutting. Dinan part number D760-0046-A. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Carbon fiber airbox with semi-open lid and auditory port
- Carbon fiber intake tube
- High-flow filter
- Air mass meter housing
- Installation hardware
Key Features
- Dinan-tested gain of up to 15 HP and 13 lb-ft at 6000 RPM
- Airbox 30% larger than stock
- Filter area 102.1 sq in vs 76.3 sq in stock, 34% more
- Intake tube removes the factory baffling and resonance chamber
- Air mass meter housing 8% larger than stock
- Semi-open lid with auditory port for more turbo sound
- Full carbon fiber construction
- About 1 hour bolt-on install
Vehicle Fitment
Fits the following B58-powered BMW F-chassis models:
- BMW M240i / F22 Coupe (2017-2021): M240i, M240i xDrive
- BMW M240i / F23 Convertible (2017-2021): M240i, M240i xDrive
- BMW 340i / F30 Sedan (2016-2018): 340i, 340i xDrive
- BMW 340i / F34 Gran Turismo (2017-2019): 340i xDrive Gran Turismo
- BMW 440i / F32 Coupe (2017-2020): 440i, 440i xDrive
- BMW 440i / F33 Convertible (2017-2020): 440i, 440i xDrive
- BMW 440i / F36 Gran Coupe (2017-2020): 440i, 440i xDrive
Not for four-cylinder 230i, 330i or 430i models, the N55 335i and 435i, or the F87 M2.
Installation Notes
Plan on about one hour with basic hand tools. Work on a cool engine and follow the Dinan instructions included with the kit.
- Let the engine cool and remove the engine cover if fitted.
- Unplug the air mass meter and loosen the clamps on the factory intake tube.
- Remove the factory airbox and intake tube.
- Install the Dinan carbon fiber airbox, filter and intake tube, and transfer the air mass meter sensor as directed.
- Tighten every clamp, reconnect the sensor, then start the engine and check for leaks and warning lights.
