If the waste gate is opened, what happens to the exhaust gases?

• A. Increase backpressure
• B. Block exhaust flow entirely
• C. Spill exhaust gases to the outlet
• D. Increase flow through the turbine

Answer: (C)

When the waste gate opens, exhaust gas is routed away from the turbine and through the bypass path to the exhaust outlet. This diverts the gas that would normally drive the turbine, so less energy is available to turn the turbine. The result is a decrease in turbine speed and a reduction in compressor boost pressure. The gases still exit the exhaust system, but they bypass the turbine rather than flowing through it. This is why opening the waste gate “spills exhaust gases to the outlet.”