Replacement Turbocharger Boost Management Components

Unlike naturally aspirated engines, where the cylinders are filled by atmospheric pressure, forced induction engines employ turbochargers or superchargers to push air into the engine, forming a dense, oxygen rich air charge in the cylinders, increasing the amount of fuel that can be added, and substantially raising power output. Forced induction creates positive pressure within the intake manifold and “boost” is the term used for the amount that intake manifold pressure is raised above atmospheric pressure. However, boost pressure must be limited to prevent engine damage and on turbocharged engines boost is regulated by a wastegate, which is controlled by boost management components.

A turbocharger consists of a turbine wheel and a compressor wheel that rotate on a common shaft within their respective housings. The turbine wheel is plumbed into the exhaust system and exhaust flow spins the turbine blades, which in turn drives the compressor wheel. The compressor section of the turbo is part of the air intake system. Air is drawn through the air filter and intake tube, compressed by the compressor wheel and forced into the intake manifold. The wastegate regulates exhaust flow to the turbine wheel, thereby controlling compressor wheel speed and boost. The wastegate may be incorporated into the turbine housing or be an external component.

A typical wastegate is controlled by an actuator containing a diaphragm and spring, which is connected to boost pressure. The actuator spring rate is calibrated according to boost pressure limit. When the wastegate is closed, boost pressure can build. When boost reaches a predetermined level, the pressure acts against the actuator spring to open the wastegate, allowing exhaust flow to bypass the turbine wheel into the exhaust system. On older turbocharged vehicles, the wastegate actuator was directly connected to boost pressure, but on modern turbocharged vehicles the wastegate is electronically controlled.

Boost is controlled by the engine control computer, which determines the appropriate amount of boost required for various vehicle operating conditions based on internal programming and input from sensors including a manifold pressure sensor and knock sensor. The computer controls boost via a boost control solenoid. Boost pressure is routed through the boost solenoid, which is wired into the engine management system. This allows the computer to control the pressure signal to the wastegate actuator. This more precise control ensures optimal power output and fuel economy with long-term engine durability. Symptoms of a faulty boost control solenoid valve would be too much boost or insufficient boost, which will in most cases set a diagnostic trouble code in the engine control computer’s memory and turn on the instrument panel CHECK ENGINE light. The solenoid valve itself may be checked by verifying airflow through the ports with and without power applied to the solenoid, and the condition of the hoses in the system should also be checked.

Whatever turbocharger boost management component malfunction you’re experiencing, we have the replacement parts to restore long-lasting performance, fuel economy and durability. Our turbocharger boost management components are manufactured according to original equipment specifications, so when service is completed you can count on the performance and reliability your vehicle was designed to deliver.