Yes, you can

A few years after this movie came out, I was reading a car magazine, and this question was brought up in a letter. While it is true that the normal supercharger is constantly driven, it was said that a clutch system could be incorperated into the drive pully, thus disengaging it. The probablity of actually doing it would but very difficult, as that once the supercharger stops turning, you have also cut off the airflow to the engine. You would have to have a secondary air intake, but the whole thing is theoretically possible.

Yes, but not with that setup.

The setup that is shown in the movie would not have been capable of being deactivated since it did not have an intake bypass.\r\rThe actual setup on the car was a supercharger shell with a carburettor inside mounted to a standard intake. The belt was driven by a electric motor from below and the supercharger pulley was mounted to a waterpump housing for it's bearings. The sound was editited in and the sudden "boost" of power was just the driver pushing the pedal down further...\r\rAs far as "could it be done," well yes, in fact it HAS been done. The mid/late '80s MR2 supercharged had a Roots (GMC style) type blower that had an intake bypass and a magnetic clutch which engaged only on wide open throttle. More recent vehicles such as the Ford Thunderbird S/C and others with Roots blowers, utilize the bypass only, since a free-wheeling supercharger only consumes a few HP and the added complexity of the clutch is not cost effective in that light.

Can be done

Either with an electrical, hidraulic or even neumatic clutch. the movie doesn´t show a detailed view of the engine, so we don´t know if the extra air intake needed to work is there, but it CAN be added and is rather easy, now, the movie show all kinds of modified vehicles, why is so immposible to build a supercharger with a clutch and an extra air intake that can be closed with a simple valve when not in use? please refute.