Turning the supercharger on or off

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

phaeton wrote:
> 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.

--
Steve W.

phaeton wrote:
> 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.



It was the Hot New Thing a hundred years ago:

http://www.eaton.com/Eaton/ProductsS...gers/index.htm

Still pretty neat.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

On May 22, 2:12*am, phaeton > wrote:
> 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

<morbo> SUPERCHARGERS DO NOT WORK THAT WAY! </morbo>

seriously, that ****ed 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

"N8N" > wrote in message
...
On May 22, 2:12 am, phaeton > wrote:
> 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

<morbo> SUPERCHARGERS DO NOT WORK THAT WAY! </morbo>

seriously, that ****ed 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.