You can fit a dump valve to a supercharger !
The purpose of a dump valve is to prevent lots of positive inlet pressure "slamming" the throttle plate shut when you take your foot off the pedal, and it also prevents the turbo from stalling as the boost has nowhere to go. Imagine lots of boost sitting in the inlet charge pipe, As the throttle butterfly closes it is would be rammed shut by the pressure outside. With the plate shut the turbo stalls and has to start building boost all over again.
The sense pipe from the DV receives its pressure signal from the inlet manifold, as the throttle begins to close the inlet "sees" vacuum rather than positive pressure, this vacuum is transmitted to the DV and the DV "dumps" the positive pressure to atmosphere - making the noise that Koolvin loves so much
This means that the turbo continues spinning at near enough full speed - and can generate fresh boost much quicker !
A free running turbocharger has lots of kinetic energy - so when your foot comes off the pedal the turbo will continue to develop boost in its normal fashion for a few seconds. With the supercharger, being crankshaft driven, as your foot comes of the throttle the blower slows down at the same rate as the engine - therefore the dump valve doent have anything like the same effect
At the end of the day- it just "dumps" excess boost pressure - it doesnt know if the boost was created by a supercharger or a turbo !!
Mark
:bannana:
