dual exhaust not working right?

[BMWOO7]

Thanks for the feedback.

I've done a number of searches on this and seen everything from what you have posted (30K miles with zero issues) to people saying that it caused Turbo failures on their 3 Series cars.

My thinking around it is that I can't see how it would possibly harm anything for the following reasons:

1) The exhaust is not being removed, just the other 50% is free flowing and opens under full throttle or above 3K RPM's.
2) BMW performance replacement exhausts are replacing the factory exhaust with even less back pressure.
3) I could be wrong, but I don't think Turbo engines require this much back pressure.
4) The back pressure isn't going away, it's just being equalized across both sides as when it's above 3K RPM's or Full Throttle.
5) Other BMW's with the same engine, such as the 535xi I used to have, had both exhausts open, no flap at all.

Personally I think the exhaust flap is there for noise only purposes for the soccer moms that are just driving to the store etc...

I'd actually like to see if anyone has ever done a dyno with this mod.

I also think that it might (while ever so slight) provide a little better fuel economy.

Thoughts...?