Armchair theory - extreme cold air intake.

[cfeng]

I'll try my best to explain this.

A turbo or supercharger system is adiabatic. It increases pressure to force more air into the engine.

The system described by beer jammer is technically another forced induction system, however instead of being adiabatic, it is isobaric, where pressure does not change since the air molecules are squeezed together by cooling.

The flaw with beer jammer's idea, which probably other people see, is that using an air conditioner as a forced induction system involves more imperfect energy transfers where energy is wasted. It employs an air conditioner which cannot surpass carnots predicted efficiency (lose about 20-30% here), then it would need some heat exchangers (20-50% loss, governed by newton's law of cooling). It would be much more efficient to use a turbo or a supercharger.