Anti lag valve?
 

anyone experiment with a dan culkin valve?
CSX 321 Buildup - The Dan Culkin Anti-Lag Valve ("D-valve")

Turbo and intercooler bypass (D-valve)
A method by which a large zero cracking pressure one-way check valve is inserted just prior to the throttle body, enabling air to bypass the turbo, intercooler, and piping during periods where there is negative air pressure at the throttle body inlet. This results in more air combusting, which means more air driving the turbine side of the turbo. As soon as positive pressure is reached in the intercooler hosing, the valve closes.

Sometimes referred to as the Dan Culkin valve.

When used in a MAF configuration, the D-valve should draw air through the MAF to maintain proper A/F ratios. This is not necessary in a speed-density configuration. - wikipedia.org

its the same concept as the syncronic valve or w/e