Actually, the dump pressure is rather light on the stock valves, with the intention of putting it immediately back into the intake for the "no turbo lag" that BMW claims. It probably dumps to early if anything. Definitely no back pressure to the turbos, this simply releases it to the atmosphere instead of the pre-compressed intake side. I'm pretty sure after market valves will hold the pressure longer before dumping compared to the OEM diverter.
As for the exposed bungs, I used pipe plugs with larger caps so that there would be no possibility of it entering the ducting...
Again, without big boost, there really is no need for a BOV or even a DV. It's all really just for some sound. This is just a way to let the pressure escape to the atmosphere instead of the intake again so you can hear the sound. It comes at the cost of having more vacuum in the intake when you start revving the next gear. The exhaust gas pressure is what will regulate how the turbo's spool.
For the second hose, you have to follow the second diverter hose to where it meets the intake pipe that feeds the rear turbo. Its a bit of a pain. Disconnect and seal.
Don't forget to secure the hoses too!
AA M3 is gone...the new...