🔍 Key Concepts

• Turbocharger response time when engine load and fuel are increased • Relationship between exhaust gas energy and turbocharger air supply • Transient behavior vs. steady-state operation in turbocharged diesel engines

💭 Think About

• When you suddenly increase the fuel/load on a turbocharged diesel, what happens FIRST: more exhaust energy or more boost air? Think about the sequence. • Does the turbocharger instantly change speed, or does it need time to accelerate? How does that affect the air supplied to the engine? • At the exact moment of load increase, is the engine briefly getting the right air–fuel ratio, or is there a short mismatch? In which direction?

✅ Before You Answer

• Be clear on whether a turbocharger can instantly increase airflow or if there is a time delay (turbo lag). • Think about the cause-and-effect chain: fuel → combustion → exhaust gas → turbo speed → boost air. • Eliminate any choice that suggests physically impossible behavior of air flow (e.g., negative pulse leaving the turbocharger in normal operation).