Magnuson Superchargers - Packed Full Of Power

The small, brass bypass valve (shown at the right), allows the supercharger to become very efficient in terms of economy and parasitic power loss. It opens by way of a controller at high-manifold vacuum, when power demands are low.

Inside the housing, the air travels from the carburetor to the rear of the housing, then into the inner cleaves of the rotors and out the bottom; this is described as an axial flow.

As boost gains momentum (accelerating) the vacuum decreases (throttle open), the bypass valve closing instantly. This allows the supercharger to increase pressure into the cylinders. This equalized vacuum condition virtually eliminates the normal power loss a forced-induction system places on an engine. CHP

Dyno Details
The dyno data on the Magnuson 122-HH supercharged 400ci small-block shows just how well this combination did. Notice how the torque, 556 lb-ft measured at 2,000 rpm, stays high throughout the rpm range. Torque below 2,000 rpm was equally impressive.