To propel these hefty, yet capable, luxury vehicles, a large volume of air is required to be fed into two powerful turbochargers. The stock airboxes that provide this air utilize restrictive panel filters and artificially limit air volume. With a few small tweaks, however, a more efficient system with increased flow capacity that yields more power can be achieved. That is exactly what Dinan has done with the revised and improved carbon fiber cold air intake system for the M550i and M850i. Retaining the factory lower boxes for simplicity but enlarging the air box lids via the removal of the unused "U" channels afforded the opportunity to be able to not only increase volume by 54%, but also allowed the use of bespoke high-flow cone filters with 22% more surface area than the factory panel filters. The improvements continue down the intake tract with the enlarged volume of air transitioning into an organically shaped intake pipe that grants a more natural and unhindered flow path into the turbo. The combination of these improved features means the engine is allowed to ingest more cold air with less restriction resulting in top end gains of +17 WHP / +18 ft-lbs of torque.
More Power: Max gains of 17 WHP and 18 lb-ft of torque @ 5500 RPM without additional modifications
34% increase in filter area (stock: 76.3in², Dinan: 102.1in²) for optimum flow
Larger volume air box (54% larger than stock) for increased breathability
Sealed system ensuring only colder outside air is utilized
