aFe Magnum FORCE Stage-2 Carbon Fiber Cold Air Intake – BMW 340i / 440i / M240i (B58)

OVERVIEW

The aFe Power Magnum FORCE Stage-2 cold air intake replaces the restrictive factory airbox on the B58-powered BMW 340i, 440i and M240i with a fully engineered induction system. A CAD-designed, dyno-tuned roto-molded intake tube feeds a large 7" conical filter, and the system flows 400 CFM at 7" H₂O for dyno-tested gains of up to +9 horsepower and +10 lbs. x ft. of torque.

This version is finished with the carbon fiber look cover, molded from lightweight vacuum-formed ABS plastic for a purposeful under-hood appearance. An auxiliary air inlet in the cover feeds additional cool air, and a urethane plug is supplied if you prefer to block it off.

Every clamp, coupling and fastener needed is in the box. The kit is a direct bolt-on that requires no cutting or drilling of factory parts.

SPECS

• Dyno-tested gains: +9 HP and +10 lbs. x ft. of torque (peak)
• Measured airflow: 400 CFM @ 7" H₂O
• Outflows the factory intake
• Filter media: aFe Pro DRY S oil-free 3-layer synthetic media (21-90096) on P/N 51-12912-C, or aFe Pro 5R oiled cotton-gauze media (24-90096) on P/N 54-12912-C
• Filter: 7" tall conical, 360-degree radial-flow element
• Intake tube: CAD-designed, dyno-tuned roto-molded plastic (aFe P/N 05-76309B4)
• Cover: lightweight vacuum-formed ABS plastic, carbon fiber look (aFe P/N 05-12912C2)
• Auxiliary air inlet in the cover, with a urethane block-off plug included
• Installation: direct bolt-on — no cutting or drilling of factory parts
• Fitment note: does not fit Convertible models
• Emissions status: not CARB exempt at this time — not legal for sale in California or for use on any vehicle registered with the California Department of Motor Vehicles.

PARTS INCLUDED

• Air filter — Pro DRY S (21-90096) on 51-12912-C, or Pro 5R (24-90096) on 54-12912-C — 1
• Carbon fiber look vacuum-formed intake cover (05-12912C2) — 1
• Roto-molded intake tube (05-76309B4) — 1
• Silicone plug (05-01387) — 1
• Silicone double-hump coupling (05-01417) — 1
• Hose clamp, #060 (03-50002) — 2
• M4 Torx screw (03-50490) — 2

TECH RESOURCES

Additional Parts Required

• None. aFe Power specifies no additional hardware, tune or fluids for this intake — it is a direct bolt-on kit that requires no cutting or drilling of factory parts.
• Installer-supplied: basic hand tools, including a T-handle or driver for M4 Torx screws and a nut driver for the hose clamps.
• Optional service item: a Pro DRY S filter is washed and air-dried only; a Pro 5R filter must be re-oiled with aFe filter oil after each cleaning.

Installation

• aFe Power 51-12912-C / 54-12912-C installation instructions (PDF)

Notes

• Does NOT fit Convertible models. Confirm fitment with Speed Logic before ordering.

PART NUMBER

• 51-12912-C — Magnum FORCE Stage-2 intake, Pro DRY S filter, carbon fiber look cover
• 54-12912-C — Magnum FORCE Stage-2 intake, Pro 5R oiled filter, carbon fiber look cover
• 51-12912-B — same kit with Pro DRY S filter and black cover

VEHICLE APPLICATIONS