Maintaining a constant manifold pressure in a turbo-charged engine during the climb will cause:

In a turbocharged engine, maintaining a constant manifold pressure during climb is crucial for consistent performance as altitude increases. As the engine climbs, the ambient air pressure decreases, which means that the turbocharger must work harder to maintain the desired manifold pressure.

To achieve this, the waste gate, which regulates the amount of exhaust gas that bypasses the turbine, would progressively close. This closure allows more exhaust gas to flow through the turbine, increasing its rotational speed and thereby forcing more air into the engine to meet the intake pressure requirements. This dynamic adjustment ensures that the manifold pressure remains stable despite changes in altitude and atmospheric conditions.

As a result, the increase in exhaust gases directed toward the turbine leads to improved boost pressure, providing the necessary performance during climbs. In contrast, if the waste gate were to open, it would reduce the turbine's efficiency by allowing excess exhaust to bypass, leading to a drop in manifold pressure, which is not the desired outcome during climb.