The Valvetronic system allows you to switch between being quiet and being loud with the push of a button via the included remote. This works by tapping into a vacuum source on your engine and connecting it to the control module. When you press the button on the remote, you are communicating with the OBDII module via Bluetooth. This OBDII module tells the exhaust valve module to allow the engine vacuum to open or close the exhaust valve. You can also set the exhaust valve module to an automatic mode which will open/close the exhaust valve based on predetermined RPM range or throttle position. Aside from getting a brutal sound with the Valvetronic system open, you can also gain power, especially if your car is turbocharged. Depending on the car, modifications, and tune you have, the valve being open will also the exhaust gas to flow more freely, as it does not have to pass through any muffler. If your vehicle is turbocharged, you may see a slight increase in boost pressure depending if you are running an open or closed boost cycle, resulting in more horsepower.