Are you on the lookout for a fantastic upgrade that won’t break the bank? The all-new G2x/G4x Mx40i PEX Intake is here to deliver the same performance and sound benefits as its carbon fiber counterpart, but with a more understated flair. This means you get the best bang for your buck when it comes to the B58 intake system from Dinan.

The Mx40i is quite the performer, but you wouldn’t know it just by looking at the uninspiring stock intake system, which is often hidden behind unfinished strut braces (where applicable). In its stock form, the Mx40i features a dry and lackluster air box that houses a basic panel filter, accompanied by an intake resonator designed to mute those exhilarating turbo and intake sounds. Unfortunately, BMW has given Mx40i owners an air box that looks bland, flows just okay, and doesn't make a peep. That’s a stark contrast to the platform’s otherwise dynamic character. Thankfully, the Dinan PEX intake steps in to make things right. It offers a semi-open intake that flows an impressive 58% more air than the stock system, leading to enhanced top-end power and improved throttle response, all while maintaining an OEM-like appearance that fits seamlessly with the factory components under the hood. Plus, you’ll enjoy a richer sound thanks to the removal of the intake resonator and the introduction of a semi-open design.

To achieve the impressive airflow that sets the Dinan intake apart, we've reworked and enlarged the entire lower box—not just the lid—to maximize every inch of available space in the engine bay. This redesign allows for a 40% larger, custom free-flowing filter, ensuring you get the most out of it. Dinan has always aimed for a secondary inlet to effectively utilize the increased volume of the air box and filter surface area. This pursuit led to extensive testing of various shapes, locations, and sizes for potential open-air inlets. We wanted to make sure that the new inlet wouldn’t lead to any unwanted side effects, like elevated air temperatures, which can be a common issue with open-air intake systems. The tests revealed that the patterned openings in the final design, located away from the engine, struck the perfect balance, enhancing volume without raising turbo inlet temperatures—no matter the testing conditions (single or multiple gear pulls, constant speed, 0-100 mph runs, and more).

With all that extra air flowing in, you’ll notice improved throttle response and a boost in power, with max gains of +9 WHP and +8 ft-lbs of torque. The secondary air inlets also make the intake system more audible, allowing you to truly appreciate the turbo spool and BOV sounds. This is a significant change from Dinan's traditional fully sealed systems, where those induction noises are much harder to hear. While power and sound take center stage, the understated PEX construction blends effortlessly into the factory engine bay, offering a refined look that still manages to catch the eye. It’s a smart solution that balances form and function for a vehicle that excels in both areas.

• More Power: Max gains of 9 WHP and 8 lb-ft of torque on a completely stock vehicle
• High heat deflection PEX construction with an OEM look
• Enjoyably louder, sportier sound
• Improved throttle response
• Outflows factory intake by 58% or more
• Larger volume air box (60% larger than stock)
• Compatible with all G2x Mx40i's, with or without factory bracing
• Quick and easy installation

• BMW M240i | M340i | M440i (2020-2024)