Following in the footsteps of its big brother on the B58 engine, the 4 cylinder intake takes the same path to success. Improve upon the factory design by increasing flow via a larger airbox and filter element thereby improving throttle response and lessening the strain on the turbocharger for maximum efficiency. While box and filter enlargement and redesign are a major factor in ultimately producing a more potent intake they are not the only variables in creating a more efficient design either. The devil is in the details which is where Dinan thrives. Coupled with maintaining Dinan's standard practice of utilizing a sealed system to ensure as much cold, outside air as possible is employed Dinan engineers focused their attention on the intake pipe itself where numerous improvements could be made. In factory configuration, the intake tube comes complete with baffling and a small Helmholtz chamber to reduce unwanted sound. As a byproduct, these features also cause a more turbulent airflow path which robs the factory system of potential power. These two specific details are diametrically opposed to our intended market's desires so the removal of these features was paramount. Through numerous iterations, a carbon fiber intake tube was developed that eliminated flow disruptions and allowed the natural sound of an unimpeded intake tract to sing. All told this thorough methodology of design allows the Dinan carbon fiber cold air intake for the B46/B48 engine to elicit gains of 6 HP and 6 TRQ at 5000 RPM on a completely stock vehicle. An impressive feat on today's turbocharged engines. Not to be outdone by the performance side of the equation the B46/B48 intake also is completely made up of carbon fiber unlike 4 cylinder intakes of the past where a mix of materials was used. Not only is the intake completely carbon construction but the quality of the material has been improved over previous generations as well. While looks are surely important, and this piece has that department covered in spades, the improved construction and coating also guarantees that the appearance of the engine bay with the Dinan intake will not be marred over time. Built to present well, perform well, and last the duration, the Dinan B46/B48 carbon fiber cold air intake is a modification that is a must for any high-performance build.