The Turbosmart PlumbBack recirculating valve in 38mm (blue) returns vented boost into the intake tract instead of releasing it to atmosphere. Intended as a quiet alternative to an atmospheric blow-off valve, the PlumbBack system preserves intake charge and provides a more muted sound profile while maintaining the recirculation behavior favored in closed-system turbo setups.

Turbosmart BOV Plumb Back Uni 38mm-Blue