As I grew up, there were various movies where the driver of the souped- up car had a blower that he could 'turn on' when he needs a little extra 'push'. I think the first one I saw was Mad Max (1979) but then all through the 1980s there were other examples, I think my favorite being "My Science Project".
Is this entirely a Hollywood Invention, or is there some historical reasoning behind this? I've never actually seen an example of a supercharger you can turn on or off in real life.
Thainx
Well the Hollywood version in Mad Max is a joke. IIRC it was a Roots style blower shown on a Holden. The problem is that it was a bare case with no internals.
However a Roots type unit could be set up to work like that the Toyota MR-2 from 88-89 had that system. It used a clutch on the unit with a bypass system the engine used while the supercharger was off. The Crossfire uses a similar system as well.
Use a Paxton style unit and you could do it even easier as it wouldn't need the bypass to operate, however it would have lag like a turbo due to the need to build pressure in the system.
It was the Hot New Thing a hundred years ago:
SUPERCHARGERS DO NOT WORK THAT WAY!
seriously, that pissed me off about Mad Max because the blower appeared to be a Roots-type (positive displacement) unit, so if you put a clutch on the blower drive to disengage it (and it'd far more likely be on the blower itself anyway than on the crank pulley; so you wouldn't see that dramatic close-up of the blower belt starting to turn after Mel Gibson hits the red candy-like button) the engine would shut down from lack of air as soon as you disengaged the blower, as the only air that could be drawn through a non-rotating Roots blower is the leakage past the seals.
I suppose it would be possible to do something similar to that with a Paxton-type (centrifugal) supercharger; in fact Studebaker did something sort of similar back in '57-58 with the variable ratio blower drive, but the supercharger was never disengaged (although the engine would have run fine with it disengaged.)
nate
SUPERCHARGERS DO NOT WORK THAT WAY!
seriously, that pissed me off about Mad Max because the blower appeared to be a Roots-type (positive displacement) unit, so if you put a clutch on the blower drive to disengage it (and it'd far more likely be on the blower itself anyway than on the crank pulley; so you wouldn't see that dramatic close-up of the blower belt starting to turn after Mel Gibson hits the red candy-like button) the engine would shut down from lack of air as soon as you disengaged the blower, as the only air that could be drawn through a non-rotating Roots blower is the leakage past the seals.
I suppose it would be possible to do something similar to that with a Paxton-type (centrifugal) supercharger; in fact Studebaker did something sort of similar back in '57-58 with the variable ratio blower drive, but the supercharger was never disengaged (although the engine would have run fine with it disengaged.)
nate
******* There used to be one that used a compressed gas cartridge or a fuel cartridge (dont remember exact details). Punch the button and you would get a few seconds of boost, but it was definitely not a full time unit. Used mostly by drag racers or street racers, I guess. Dont think it was ever too popular. I guess nitrous sprays are the modern solution to this problem.MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.