VTA BOVs vent to atmosphere to make the signature turbo blow-off sound, where the DV+ recirculates the air to keep it quiet. Each valve in the VTA range is designed specifically for the applications we list them for, ensuring the best fit and performance. Most of the VTA range are designed for use on cars with solenoid type factory diverter valves, and in those cases the VTA kit will retain the solenoid and ECU control