Dinan 20-25 BMW X3M/X4M Cold Air Intake

Despite its unorthodox appearance and seemingly haphazard design forced to fit in limited available space, the OEM intake system is incredibly efficient. Wholesale improvement upon the design given the packaging limitations meant that a full re-design was not going to be feasible at a price point that would be accepted so a simpler more direct approach was taken. Improve air flow in the factory system where it was restricted – the filters themselves. Simply going from the stock paper filters to the Dinan multi-layered cotton filters not only increased flow by nearly 20% but also resulted in some modest power gains in the mid and upper RPM range. While happy with the results, the engine bay remained lack luster and devoid of any visual hallmarks.