Ok a BOV is a device "down the line" after the turbo to release air pressure in the intake after it reaches a predetermined value. There is several different types and ways they can be hooked up but the sequential BOV is valve type BOV with a primary and a secondary valve that helps with keeping the condition better and helps with sending out just "enough" air to make sure you don't run super rich.
next to the blow off switch
A splitter valve has a blow off valve sound but it redirects the airflow. It combines the features of a diverter valve and blow off in one housing.
It already has a blow off valve on it, and a rather good one.
These BOV's are called super-sequential blow-offs. HKS and Greddy make excellent, top-of-the-line SS-BOV models.
No, without a turbo, there is no blow off valve. However, if you really wanted to, they have fake blow off valves for sale. These mimic the sound of a blow off valve. It would be an absolute waste of money, but hey, it's your money.
Blow-Off Valve
Blow off valve faulty or expansion tank needed at water heater.
It doesn't
eBay
You could mount it, but there is no pressure to blow off.
either a forge 004 blow off valve or a forge splitter, a partial blow off valve and partial recirculation valve. which is what i run on my a4. you may be able to find better prices of these somewhere else online, i never checked,
you can get a fake sounding blow off valve, other wise bov's are used for force induction application.