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. , Like the DV+ though, it replaces the weak factory valve internals to ensure strength and reliability, especially in high boost applications. Other versions of the VTA are designed for use on cars that do not have any kind of factory-fitted diverter valve. , , Vehicle manufacturers have deleted the troublesome solenoid type diverter valve from some of the newer models, but this leads to turbo compressor surge which can be taxing on the turbo in the long run. , The VTA valves for these cars are designed to re-introduce the function of a diverter/blow-off valve to help protect the turbo in the long term and also provide a blow-off sound.