Maybe he's talking about superchargers with a bypass valve that is not
vacuum operated?

Sudhir

On 6/1/07, Andrew Grebneff <andrew.grebneff@stonebow.otago.ac.nz> wrote:
> ..Has anyone considered supercharging for the Vanagon?
>
> Yes. I have seen many postings on exhaust-driven superchargers (turbos).
>
> >   It's also my understanding that the boost from a supercharger can be
> > 'dialed' to the desired level, right from a dash knob...So if you are
> > just donking down a flat road in no particular hurry, you can use Zero
> > boost but if you need some power, you just dial it up a bit and cram
> > more air/fuel mixture into the cylinders...
>
> Don't think so. The speed of a belt-driven supercharger (and hence the
> boost) is set by the diameters of the drive & driven pulleys.
>