Looking for more performance without the flashy fanfare? The all-new G2x/G4x Mx40i PEX Intake delivers all the power and acoustic advantages of its carbon fiber counterpart, minus the showmanship. It represents the ultimate value proposition for B58 intake systems, offering the best horsepower per dollar from Dinan.

The Mx40i models are already impressive in performance and style, but their lackluster stock intake system, often obscured by seemingly unfinished strut braces, fails to convey their true potential. The Mx40i sports a drab, uninspiring air box housing a primary panel filter in its stock configuration. It's accompanied by an intake resonator designed to muffle the turbo and intake noises enthusiasts love. Essentially, BMW equipped Mx40i owners with an air box that lacks visual appeal, provides decent but not optimal airflow, and silences the sounds that excite the platform.

The Dinan PEX intake for the Mx40i corrects these shortcomings. Its semi-open design significantly improves airflow, allowing 58% more air to pass through than the stock system. This leads to increased top-end power and enhanced throttle response. It also introduces a more OEM-like appearance that seamlessly integrates with other factory under-hood components while boosting the engine's auditory appeal. This transformation is achieved by removing the intake resonator and adopting a semi-open design.

To achieve the superior airflow that distinguishes the Dinan intake system, the lid, and the entire lower box has been redesigned and enlarged to make the most of the available engine bay space. This accommodates a 40% larger, custom, free-flowing filter, ensuring maximum airflow.

Dinan also sought a secondary inlet to utilize the expanded air box and filter surface area effectively. After conducting numerous experiments with different inlet shapes, locations, and sizes, the aim was to ensure that the additional inlet didn't lead to undesirable side effects, such as elevated air temperatures. This is a common concern with open-air intake systems, which can draw in hot engine bay air. Extensive testing confirmed that the patterned openings on the opposite side from the engine in the final design of the box offered the perfect balance of added volume without raising turbo inlet temperatures, regardless of the testing conditions.

With the system drawing in more air, throttle response is improved, and additional power is unleashed, resulting in maximum gains of +9 horsepower and +8 foot-pounds of torque. The secondary air inlets also make the intake system more audible, allowing enthusiasts to appreciate the turbo spool and blow-off valve sounds. This marks a departure from Dinan's conventional fully sealed systems, where induction noise is less prominent.

While power and sound take the spotlight, the unassuming PEX construction effortlessly blends with the factory engine bay, offering a discreet aesthetic that still grabs attention. It's an economical solution that combines both form and function for a vehicle that embodies both worlds.