Silly supercharger question.

[CMF_queazocotal]

A source of inefficiency at low throttle settings is
dragging the air through the nearly closed throttle.

If the supercharger were connected to a variable gearbox,
then in principle could it make low speed more efficient?
Intead of the energy used in dragging the air through the throttle just being used to heat the air through turbulence, it is partially recycled into the engine through the drive pulley.

 

[CMF_Sean]

Then you lose power

Superchargers are connected to a clutch system that can engage when a hobbs (pressure switch) senses too much vacuum (ie when throttle is closed) but most people bypass this for better response

Sean

 

[CMF_queazocotal]

Of course you lose power.
That's the whole point of a throttle.
I was wondering if the pumping losses through the throttle would be eliminated, leading to the only inefficiency being exhausting at a lower than normal pressure, for lower fuel use at lower power settings.

The idea is to use the supercharger to reduce the intake pressure, much as the throttle does, but instead of just wasting the power used to drag the air through the throttle plate, it recycles it into the engine.

Off to find a mathematical model of an engine - though it's not a very practical idea.