aFe Magnum FORCE Stage-2 Carbon Intake 54-81012-C – BMW 128i / 328i (N52)

OVERVIEW

The aFe Power Magnum FORCE Stage-2 Si is a fully sealed cold air intake for the naturally aspirated N52 inline-six. A one-piece sealed housing isolates the filter from under-hood heat while dual "kidney" grille auxiliary ducts feed it additional outside air, and a CAD-designed, dyno-tuned roto-molded tube replaces the restrictive factory plumbing. This is the carbon fiber look version with the pre-oiled Pro 5R filter.

Installation is bolt-on with no cutting or drilling of OEM parts, and the factory MAF sensor transfers directly into the aFe tube — no tune or MAF adapter required.

SPECS

• Max gains: +12 HP and +16 lbs. x ft. torque
• Outflows the factory intake by 56%
• Filter: Pro 5R pre-oiled, washable and reusable — 5 layers of progressively finer cotton gauze mesh between polyurethane top and base
• Filter size: 6 in F x 7-1/2 in B x 5-1/2 in T (inverted) x 5 in H
• Intake tube: CAD-designed, dyno-tuned, roto-molded high-quality plastic
• Housing: one-piece sealed design with dual "kidney" grille auxiliary air inlet ducts
• Cover: vacuum-formed ABS plastic with carbon fiber look finish
• Coupling: 3.1" ID x 3" L silicone bellow with premium clamps
• Factory MAF sensor transfers to the aFe intake tube — no tune required
• No cutting or drilling of OEM parts
• CARB EO# D-550-38 — street legal
• Fits both active and non-active steering

PARTS INCLUDED

• 1x Pro 5R air filter (24-91054)
• 1x Intake tube (05-81012B5)
• 1x Housing (05-81012B2)
• 1x Carbon fiber look cover (05-81012C3)
• 1x Silicone bellow coupling, 3.1" ID x 3" L (05-01542)
• 2x #048 clamps (03-50007)
• 1x Brass 1/8-NPT fitting (03-50191)
• 1x Brass 1/8-NPT plug (03-50410)
• 2x M4 screws for MAF sensor (03-50490)
• 2x M6 lock washers, 4x M6 flat washers, 4x M6 hex screws
• 2x Grommets (03-50033)
• 7x 5/16" button head screws (03-50259)

TECH RESOURCES

Additional Parts Required

• None. This is a complete bolt-on kit — aFe specifies no additional hardware and no tune.
• Customer-supplied tools: 6mm, 8mm and 10mm nut drivers or sockets, socket wrench, flat-head screwdriver, panel popper.
• Service items (not required at install): replacement Pro 5R filter 24-91054; Pro 5R restore kit 90-50501 (8 oz squeeze oil + 12 oz cleaner) or 90-50001 (aerosol); Filter GUARD pre-filter 28-10093.

Installation

• aFe Power 54-81012-C installation instructions (PDF) — official aFe manual, covers 54-81012-C, 51-81012-C, 54-81012-B and 51-81012-B.
• CCV/PCV: use the supplied brass 1/8-NPT fitting on cars with a crankcase breather hose, or the brass plug on cars without.

Notes

• Per aFe: 328i and 128i applications exclude certain LEV2 SULEV engine test groups.

PART NUMBER

• 54-81012-C — Magnum FORCE Stage-2 Si, carbon fiber look trim, Pro 5R oiled filter
• Related aFe variants: 51-81012-C (carbon look, Pro DRY S) · 54-81012-B (black trim, Pro 5R) · 51-81012-B (black trim, Pro DRY S)

VEHICLE APPLICATIONS