I have a 2008 mini cooper s with turbo and was wondering if it has a BOV??

 

Same will say so and in conversation it is oft referred as such, but it's actually a diverter valve, not blowing off to atmosphere.

Questions?

 

The actual answer is yes. Both a diverter, or a blow off valve both accomplish the same purpose, but in different ways.

What happens when you are charging along, under full boost, and you jump off the throttle?

The turbo is still trying to pack in air. It is a pump spinning at 100,000+ rpm after all. Well if you don't do something, that pressure will back up and try to stall the compressor. So you open a valve and either dump the pressure to atmosphere, (not the best solution... but it does sound cool.) or you can direct the pressure to the intake side of the turbo.