AV002I-011 SPRING - RACE VALVE

 The picture shows the entire race valve assembly, but this is just for the spring. 

Importance of Bypass/Surge Valves
Applications utilizing intercooling and those operating at boost
levels in excess of 8 psi will benefit from the use of a bypass
valve (commonly referred to as a “surge” valve). In high RPM,
low load conditions, the supercharger is still operating at full
speed and attempting to deliver full flow. With the throttle
blade(s) at or near the fully closed position, the engine is unable
to accept the airflow from the supercharger. In this event the
pressure builds until the flow attempts to reverse direction and
exit through the compressor, resulting in a harmful condition
known as compressor surge. Installing a bypass valve between
the supercharger discharge and the carburetor/throttle body
prevents damaging compressor surges by diverting the
undemanded charge air to the atmosphere during manifold
vacuum conditions. ATI’s butterfly-type Pro-Flo is well suited
for applications making 750 hp
or less. Applications at
higher power levels are
best suited for use
with our
poppet-style
race valve.