In an externally driven turbocharger, does the compressor act before or after mixing with metered fuel?

In an externally driven turbocharger, does the compressor act before or after mixing with metered fuel?

• A. After mixing with metered fuel from the carburetor.
• B. Inside the carburetor.
• C. Before mixing with metered fuel from the carburetor.
• D. After the exhaust.

Answer: (C)

In an externally driven turbocharger system, boosted air must be created before the fuel is added. The exhaust gases drive the turbine, which powers the compressor to pressurize intake air. That pressurized air then goes to the carburetor, where fuel is metered into the boosted airstream to form the combustible mixture that enters the engine. Mixing fuel with air before it’s compressed would mean the turbo is compressing a fuel‑laden charge, which is not how these systems are designed and would lead to poor fuel metering, possible misfire or damage, and improper combustion. The carburetor’s metering relies on the boosted air coming in, so the compressor acts before mixing with metered fuel from the carburetor.

In an externally driven turbocharger system, boosted air must be created before the fuel is added. The exhaust gases drive the turbine, which powers the compressor to pressurize intake air. That pressurized air then goes to the carburetor, where fuel is metered into the boosted airstream to form the combustible mixture that enters the engine.

Mixing fuel with air before it’s compressed would mean the turbo is compressing a fuel‑laden charge, which is not how these systems are designed and would lead to poor fuel metering, possible misfire or damage, and improper combustion. The carburetor’s metering relies on the boosted air coming in, so the compressor acts before mixing with metered fuel from the carburetor.