DINAN – Closed Cold Air Intake – BMW M240i / 340i / 440i (16–21)

DINAN – Closed Cold Air Intake – BMW M240i / 340i / 440i (16–21)

Following in the footsteps of the acclaimed Dinan N55 intake system, this next-generation cold air intake for the B58 engine continues the legacy of precision engineering and performance. The Dinan Closed Cold Air Intake optimizes airflow with a larger airbox and high-flow filter to reduce restriction, improve throttle response, and enhance turbocharger efficiency — all while maintaining the clean, OEM+ refinement of a fully sealed system.

The airbox has been enlarged by 30%, while the filter area has grown by 34%, ensuring the turbocharger receives a steady supply of cool, dense air. The redesigned carbon-fibre intake tube eliminates factory baffling and the restrictive Helmholtz chamber, resulting in a smoother, uninterrupted airflow path that minimizes turbulence and pressure loss. The outcome is a measurable performance increase of +15 HP and +13 lb-ft at 6000 RPM on a stock vehicle — remarkable gains for a simple bolt-on upgrade.

Built entirely from premium 2×2 gloss carbon fibre, this intake is engineered for both strength and longevity. Its UV-resistant finish preserves the deep weave pattern and luster for years to come, ensuring your engine bay looks as good as it performs.

Features & Benefits

• +15 HP / +13 lb-ft @ 6000 RPM (+13 WHP / +11 WTQ on stock tune)

• Sealed airbox design for maximum insulation from engine heat

• 30% larger airbox volume and 34% larger filter area (76.3 in² → 102.1 in²)

• Optimized carbon-fibre intake tube eliminates restrictive factory baffling

• 8% larger air-mass-meter housing for improved flow and throttle response

• Enhanced turbo sound with refined tone under acceleration

• Full 2×2 carbon-fibre construction with UV-resistant clear coat

• Quick and easy bolt-on installation

• 50-State Emissions Legal: CARB EO D-176-56 (2019–2021 F2x/F3x M240i / 340i / 440i)

Fitment Table: