Forge Motorsport's IPCV or "Internal Pressure Compensation Valve" is a clever answer to the problem of matching a Dump Valve's internals to increased boost pressure.Whereas previously you'd have to carefully balance the strength of the spring in the valve to whatever the increased boost pressure was, this valve instead uses boost pressure from the turbo in place of the spring in the dump valve.This means instead of having to carefully tune the spring used to match the boost level the valve always self adjusts allowing for different boost levels (e.g. in systems running boost controllers or switchable maps) or very high boost levels. It also means you don't need to worry about incorrectly tuning the valve.