To produce peak manifold boost from a VN-type turbocharger, where should the vanes be positioned?

To achieve peak manifold boost from a VN-type turbocharger, the vanes need to be positioned in the nearly closed position. This configuration allows the turbocharger's geometry to optimize the exhaust gas flow through the turbine, increasing the velocity of the exhaust gases and thereby enhancing the turbocharger's efficiency and response.

When the vanes are nearly closed, they effectively restrict the flow, which increases the pressure at the inlet of the turbocharger, allowing for a higher boost pressure in the manifold. This is crucial for maximizing engine performance, particularly under load conditions where maximum power is required.

In contrast, if the vanes were fully open, the turbocharger would not be able to create sufficient pressure as the exhaust would flow too freely and not allow for adequate turbine speed. A fully opened wastegate would also reduce the amount of exhaust gas directed through the turbocharger, preventing it from achieving the necessary boost levels for peak performance. Similarly, a fully closed wastegate can lead to excessive boost pressure but does not pertain directly to the position of the vanes relevant in this scenario.