[Christ]

Originally Posted by hawk2100n

Actually timed pulses from a roots blower is a good idea and wouldn't be too difficult. You would need a blower running at engine speed with n/2 lobes where n is the number of cylinders. And timing isn't complicated because you could put it on a toothed belt like top fuel dragsters and extremely high performance cars do. And timed pulses could keep a more even pressure inside of the manifold.

I would love to be in engine development. Maybe one day...

Roots blowers generally use a helix type rotor design to help smooth the pulses out. Only very old designs use "impulse" style charging, because it creates a pulse frequency that can make proper fueling very difficult.

Thus, there's really no way to "time" the pressure pulses exactly to a specific event, since the design is meant to provide steady pressure, rather than pulsed pressure.

Even if you designed a blower that provided pulses, it would only serve to enhance the effects of helmholtz tuning (frequency-based freeair supercharging), and wouldn't provide much of an efficiency gain over just charging and maintaining pressure in the intake tract.