Audi RS4 B7 Intake Manifold Variable 4.2 FSI Petrol Quattro BNS 079133185AS

Audi RS4 B7 Intake Manifold Variable 4.2 FSI Petrol Quattro BNS is a component from the Intake manifolds group, designed to work with the V8 FSI petrol unit in the quattro system. The variable geometry of the manifold allows for precise management of cylinder filling, which translates into dynamic engine characteristics and stable operation across the entire rev range.

Specifications and technical data

• SKU: 079133185AS
• Mark: Audi
• Condition: Used
• OEM Part Number: 079133185AS
• Substitutable numbers: 079133185AS, 079 133 185 AS
• Fuel type: Petrol
• Part type: Intake Manifold
• Category: Intake Manifolds

Purpose and function in the 4.2 FSI engine

The presented manifold has been developed for the naturally aspirated FSI petrol unit, where it is responsible for directing air into the cylinders and working with the variable intake runner length system. Thanks to this, the engine can maintain favorable torque at low RPM while ensuring free breathing at higher engine speeds. A properly selected intake manifold is crucial for:

• stable operation at idle and in the mid-RPM range,
• correct throttle response during dynamic driving,
• maintaining factory power and torque parameters,
• compatibility with the BNS engine control unit software.

Construction of the variable intake manifold

The manifold design utilizes a variable runner length system, where internal flaps and air guides switch depending on load and RPM. This type of solution allows for the optimization of mixture swirl and air flow velocity, which is particularly important in high-revving V8 FSI units. This solution supports:

• more uniform filling of individual cylinders,
• better refinement during partial load,
• more effective utilization of the exhaust system and ignition timing potential.

Benefits of using an original Audi manifold

Choosing a manifold from the Audi group means maintaining factory runner geometry, mounting points, and accessory interfaces. As a result, installation is predictable, without the need for modifications, and the intake system remains consistent with the manufacturer's specifications. The main advantages include:

• compatibility with the factory engine management and existing wiring harness,
• preservation of the stock performance characteristics of the 4.2 FSI unit,
• proper fitment to cylinder heads, throttle body, and other intake components,
• consistency with the lubrication and cooling system in the engine bay.

Application in the quattro drivetrain

In the RS4 B7 model with quattro all-wheel drive, the intake manifold works with an advanced drivetrain system, where smooth power delivery has a direct impact on vehicle traction and stability. A functional manifold helps maintain predictable throttle response, which is important both during track driving and in daily use. The proper condition of the intake system reduces the risk of power loss, uneven engine operation, or error codes stored in the ECU, which is significant for diagnostics and further vehicle maintenance.

Condition, verification, and selection of parts

The item is offered in used condition, which allows for an economical restoration of the intake system while maintaining the original specification. Before installation, a standard visual inspection is recommended, as well as checking the freedom of movement of the flaps and the tightness of connections, so that the manifold can work seamlessly with the FSI petrol unit. When selecting this component, it is worth verifying compatibility with the engine code and accessory configuration to ensure full functionality of the variable intake and avoid installation mismatches. If you are planning a comprehensive repair or upgrade of the engine area in your Audi and need other elements from the same group, such as intake manifolds, intake runner components, or intake housings, check the available parts in the Audi intake manifolds category. For a better understanding of the impact of engine operating temperature on the durability of intake accessories and the entire engine, you can refer to an article describing practical aspects of diagnostics and maintenance of the cooling system: Engine cooling system – overheating, repair, and used radiators.