Product Name:Banks Power Monster Ram Turbo Inlet Elbow (Red) - 17-24 Duramax L5P
Manufacturer: Banks
Manufacturer Part #: 42792-R
Thoroughbred Diesel Part #: BAN42792-R
Fitment Notes: 2017-2025 GM Duramax L5P

The Banks Monster-Ram Turbo Inlet for the 2017-2025 Duramax L5P is the only intake elbow that outperforms stock without the destructive effects of turbo surge. More than a year in development, the Monster-Ram increases air mass flow to the compressor. This results in slower turbo shaft speed and a reduction in time to boost. With slower shaft speeds, throttle response is improved, and turbo life is increased.

Duramax L5P Turbo Inlet with Anti-Surge. Raw Aluminum

Note:

• Works with Banks Ram-Air and stock intake systems.

Banks Power Monster Ram Turbo Inlet Elbow Features:

• Maximum safe performance with no turbo surge
• 23% Greater Gulp Capacity™ (volume)
• 17% Larger turbo inlet size
• 18.67% Less restriction vs stock
• Outflows stock by 11.9%
• Retains PCV geometry for air-oil separator
• OE-quality aluminum casting
• Banks red powder coat Or Natural aluminum for custom coating
• 50-state CARB-EO pending

Turbo Induction Perfection

With 18 months of development and over 40 prototypes tested, the Banks Monster-Ram for the Duramax L5P is more than just attractive. It's turbo induction perfection.

Every facet from inlet and outlet size, orientation and location of the PCV connection, and down to the angle of the ported shroud interface had to be dialed in to exacting tolerances.

Mass Air Flow has been improved by almost 12% by removing stock restrictions at the turbo inlet all while preventing destructive turbo compressor surge and maintaining emissions compliance.

All other designs we found on the market and tested aginst, either outflow stock at the expense of your turbo and emission systems, or flow less than stock by the time they are restrict back down with an inferior anti surge design.

The Monster-Ram's propriety design reduces pressure loss by 18.67% at the compressor inlet which results in an impressive 6.01lb/min gain in Mass Airflow verses stock. Benefits include improved throttle response, lower shaft speed, and increased turbo life.

Superior Engineering

To improve airflow to your turbo, a large organic shape is used compared to stock.

Cast from A356 Aluminum alloy and finished in Banks red powder coat or available in natural aluminum for custom coating, the Monster-Ram offers OE quality fit, finish, and durability.

Areas on the factory inlet that choke down are widened. Abrupt changes to that airflow have been smoothed to provide the least resistance and pressure loss.

With overall flow area increased by an impressive 17%, the turbo inlet side of the Monster-Ram was the most engineering intensive part to design.

The geometry of the anti-surge ring has been painstakingly engineered to redirect this airflow back into the compressor wheel, thereby damping compressor surge.

While it may seem simple to oversize this opening and increase airflow, a larger diameter outlet without the correct anti-surge geometry will result in compressor surge.

Adding an anti-surge ring after-the-fact only restricts airflow. Our tests of large outlet diameter aftermarket elbows retrofitted with anti-surge rings showed a pressure drop equal to the factory intake elbow. In other words, it completely negated all airflow benefits, matching or underperforming stock.

Turbo Surge Explained

–President and Chief Engineer Gale Banks explains surge.

Turbo compressor surge is mild to violent air instability that occurs in a turbo compressor when asking for high boost at low Mass Air Flow (MAF). Under these conditions, the compressor wheel loses its grip or ability to compress this low air mass to the pressure requested by the engine calibration. Suddenly, the pressure in the boost tube leaving the compressor wheel is higher than the air exiting the compressor wheel. The flow reverses through the wheel and into the intake air system! This results in moderate to huge swings in boost pressure and causes flow rate fluctuations where the direction of airflow through the compressor changes from forward to reverse.

Mild compressor surge can be almost silent but its effects can be measured with proper instrumentation. Even in mild form, surge causes hotter than normal boost air as the flow reversal causes the boost air to pass through the compressor repeatedly before reaching the engine. Surge also overheats the compressor wheel, shock loads the turbo thrust bearing, and requires more exhaust pressure to drive the turbine. This reduces throttle response, kills your turbo life, performance, and fuel economy.

Compressor “deep surge” is audible and more violent. When this happens, the amplitude of boost pressure and MAF fluctuations increase dramatically as does the boost air temperature. Hot reverse flow boost air blows back into the intake pipe every time you hear a pulse or whoosh. Then the air goes back through the compressor, heating it even more! Running your turbo in deep surge can destroy the compressor wheel and beat the thrust bearing to death. Deep surge dramatically diminishes performance, fuel economy, and can kill your turbo and engine. And, you can’t remove surge by “tuning it out” without further diminishing your engine’s performance.

Altering or removing this geometry defeats the anti-surge system entirely, amplifying the damage.

To prevent surge, various surge control system are employed to reduce the impact of the damaging reverse flow pulse and reduce the noise. On the Duramax L5P a slot in the compressor inlet bore feeds the pulses into an annular volume shaped somewhat like a donut. Here the pulse is diffused and the temperature and pressure spike is reduced. The boost air then makes a U-turn and re-enters the intake air through a pathway that is defined by the marriage of the turbo compressor housing with a correctly machined inlet elbow.

They all surge!

Of the competitive turbo inlet elbows tested, all cause surge. Some claim to have anti-surge rings that are nothing more than decorative. They do not help the air make a smooth U-turn. Others who claim to have anti-surge rings more closely resembling the stock elbow, do not have the precise geometry required to prevent surge. Tests prove that being off a few thousandths of an inch results in surge. There are currently two on the market with identical geometry as the stock anti-surge ring. However, they flow less than stock because the elbows are made of welded pieces of tubing. Air doesn’t like corners.

Other brands offer a fabricated inlet elbows that causes surge. To fix this surge, 3rd party aftermarket tuners offer an anti-surge ring that bolts on between the turbo and inlet. The irony is that after the bolt-on anti-surge ring is attached, the elbow flows less than stock.

– Gale Banks | President & Chief Engineer