Dump valve for supercharger
Turbo Mini Forums

I now that a simple dumb valve don't worck very well on a blow setup supercharger, but if I put 2 dump valve:) whit a t piece on the manifold job? what we think?

A dumb valve on a supercharger doesn't sound very clever.

In the 13's at last!.. Just

Gaincooper,

I thought the main point of a dump valve is to prevent surge within the turbo stalling the turbine shaft upon rapid closure of the throttle butterfly, thereby prolonging the life of the unit and reducing lag whilst the engine waits for the shaft to be accelerated again by exhaust gas.

Superchargers by their nature are more robust (assuming a twin rotary screw type) so is there a need for as dump valve at all when this feature is normally associated with turbos ?

Why have all that expensive compressed air wasted to atmosphere ?

Conversely, the charger doesn't need exhaust gas to drive it so there should be less lag as the air delivery is engine speed related.

Richard.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

is it going on a suck through or blow through set up. If suck through then surely when the valve is open it will be blowing unburnt fuel out...

with a blow through setup which i think is the way you were going the back pressure still builds up putting extra strain on the supercharger and belt also it will push past the carb and self rev (i know someone who tried). double or multiple dump valves may work or get yourself the valve from the bmw mini it is a vacume opperated buterfly valve which will dump the boost when your oot comes off. On the bini it is plumbed back into the supercharger inlet but you might not want to. The amount of air produced on run down is pretty amazing.

My small bore turbo project http://www.turbominis.co.uk/forums/index.php?p=vt&tid=473901

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will