The stock 2020-23 L5P intake is built around noise control, vibration isolation, and factory air-mass limits. That leaves restriction in the bellows, resonators, filter, and sensor area right where the turbo needs clean airflow. The Banks Ram-Air Intake System fixes that with a larger, smoother intake path, a massive enclosed filter housing, outside-air feeds from the grille and fender, and an EPDM bellowed elbow that keeps engine movement from disturbing airflow. The key is our patented Air Mass Control Module. On this platform, you cannot just increase tube size past the factory sensor section and expect the ECM to stay happy. This module corrects the signal back to the ECM, which frees us to build a true high-flow intake instead of choking everything back down at the sensor. The result is 58% more mass airflow than stock, less restriction ahead of the turbo, sharper response, and stronger induction sound.
The video introduces Banks' new intake system for 2020-and-newer Duramax L5P trucks, covering GMC and Chevrolet 2500 and 3500 pickups with the 6.6-liter diesel. The central engineering difference is a patented Banks Air Mass Control Module, which allows Banks to redesign the intake path beyond the limits imposed by the factory sensor arrangement.
The recap begins under the hood with the stock airbox. Air enters the factory system from two locations: a front inlet connected to the grille for a ram-air effect, and an upper duct connected to the hood scoop. As air is drawn toward the turbocharger, it passes through an inline resonator and corrugated bellows. According to Banks, those features primarily exist for noise and vibration reduction, but they also add resistance and drag to the intake path.
Banks highlights several sources of restriction in the factory system. The corrugated bellows allow movement, but their shape effectively reduces cross-sectional area and chokes airflow. Inside the airbox, the factory filter appears large at first glance, yet Banks argues that multiple design choices limit performance. The filter is covered by wire mesh, which obstructs airflow, and the opposite side uses a polyfill layer. The pleats are packed closely together, which Banks says favors dust collection rather than airflow.
The stock airbox housing also contains extensive internal webbing and ribs. Because the factory box is injection-molded plastic and relatively thin, those ribs are needed for strength and durability. Banks' criticism is that the ribs create additional internal disturbance and also transfer engine heat into the airbox. The upper hood-scoop duct is also shown as a restriction point: although it begins at full diameter, it necks down quickly, then forces incoming air to travel downward, make a 180-degree turn, and move back upward into the filter. In Banks' assessment, the factory system is engineered well for sound reduction and dust collection, but not for maximum airflow performance.
Banks contrasts the stock design with its Ram-Air airbox. Instead of injection-molded plastic, the Banks box is made from cross-linked polyethylene. Because the material is denser, the housing does not require the same internal strengthening ribs, leaving the interior smooth and open. The stated goal is to eliminate unnecessary surfaces that create resistance or drag.
The Banks box still uses a front duct connected to the grille for ram-air effect, but it adds a side inlet that draws from the fender area. That side inlet is positioned higher and farther from the elements, and Banks notes an additional side effect: it makes turbo sound more audible. The overall design emphasis is a cleaner internal path and more usable inlet area rather than the stock system's focus on noise suppression.
A major part of the system is Banks' large conical filter, referred to in the video as the trademarked Big Ass Air Filter. Banks says the filter was not made large simply for appearance; instead, its dimensions and geometry were developed using CFD. That includes the number of pleats, pleat depth, filter-media thickness, material selection, and even the wire mesh. The company describes the filter as a proprietary custom design.
At the outlet side, the filter uses a collar that transitions into the intake tube. Banks specifies a 6-inch by 8.5-inch opening, for a total flow area of 51 square inches. In the video, that is described as more than twice the area of comparable offerings from AFE and S&B. Banks also argues that some competing filters use too many pleats, overly thick mesh, or an outlet that is too small. In S&B's case, Banks specifically criticizes the outlet for being undersized and offset, which it says creates uneven airflow through the filter and leaves part of the filter volume underused. Banks claims that even when flow-benching those competing filters, its own design still flowed 18% better.
The filter is also mounted at a downward angle inside the airbox so debris can fall out of the pleats instead of remaining trapped in them. The outlet collar is shaped to mate directly with the Super Tube and smooth airflow from the filter into the intake tract.
The engineering problem Banks focuses on next is the factory mass air flow sensor, referred to in the video as the MAF. The sensor is inserted into the intake duct like a blade and is calibrated for a specific cross-sectional area. Banks explains that if an aftermarket intake increases tube diameter without compensating for that calibration, the sensor reading sent to the ECM will be incorrect and can trigger a check-engine light.
That factory calibration is presented as the main reason competing systems remain constrained near stock diameter at the sensor location. Even if a competitor starts with a larger opening upstream, the tube must neck back down where the MAF is located. Banks shows examples from S&B and another competitor where the intake begins large but shrinks back to factory-size dimensions at the sensor section. In one example, Banks points out that the section becomes oval and places the airflow measurement on a bend, which it presents as a poor measurement environment.
Banks says its patented Air Mass Control Module is what removes that design limitation. The module connects to the factory sensor system and sends a corrected value back to the ECM. In Banks' explanation, this allows the intake to use a much larger Super Tube and a freer-flowing filter arrangement without causing check-engine lights.
The module is described as correcting for airflow effects related to tube diameter while also accounting for pressure, which in turn allows Banks to use a larger filter and less restrictive intake path. The practical result is that Banks is no longer physically locked to the factory sensor cross-section. Instead, the intake can be designed around the largest practical geometry that fits in the truck. Banks emphasizes that this module is patented and claims that competitors therefore remain limited to factory-diameter constraints at the sensor section.
The Banks Super Tube connects to the top of the airbox and mates directly to the filter collar for a smooth transition. The company then adds another design feature at the turbo connection: a flexible elbow system intended to preserve both movement and airflow.
Rather than using silicone, Banks makes its elbows from EPDM synthetic rubber. The stated reasons are rigidity, resistance to collapse, and durability against rain, heat, and cold. The bellows slide over the Super Tube and lock into place while maintaining the same general location as the factory connection. Banks argues that this arrangement allows airflow to pass cleanly through the bellows and into the turbo while still accommodating engine movement.
That movement matters because the airbox is mounted to the frame while the engine rocks and vibrates independently. Banks says its bellows are aligned with the direction of vibration so the system can absorb motion without disturbing the turbo inlet path. By contrast, the video criticizes competitor designs that place a silicone coupler on the turbo side, arguing that engine motion can misalign the turbo inlet and reduce performance.
Banks summarizes the system as its highest-flowing, lowest-restriction intake for the L5P platform. The headline claim is 58% more mass airflow than stock, with Banks stating that this exceeds both AFE and S&B. The company ties that airflow improvement to reduced intake restriction, which should lessen the workload on the turbocharger.
According to the video, the expected vehicle-level effects are improved turbo efficiency, better fuel economy, and better throttle response. Banks also notes that gains become more noticeable on tuned trucks, including those using a Derringer or other tuning. The overall engineering argument is that the intake's performance advantage depends on the combination of the larger airbox and filter, the smoother Super Tube path, the vibration-tolerant elbow design, and especially the patented Air Mass Control Module that allows the system to move beyond factory sensor-diameter limits.