the spring is designed to open under vacuum conditions to allow for the air to bypass into the exhaust manifold

This Improved 'working ratio' is achieved through an increase to the effective surface area of the diaphragm & revisions to the actual springs fitted resulting in greater leverage of the forces the actuator is working against (boost and backpressure) while still being super-responsive

The Supercharger-Specific PorPort features a softer ((4 In Hg) spring so it can stay open at idle when the supercharger is still producsing boost

Also Available in Dual Stage Boost Controller & In Cabin Boost Controller

Various AR options

VW Golf/Jetta MK2/3 Vento (83-99) RN 5/2.5kg.mm Ukendt the spring is designed toNo Top Mount No Top Mount 5 2. 5kg. mm