[xq_zhu]

Correct me if I am wrong, but I thought the stock air box of e90 is alreay a CAI, right? The engine suck in air through a sucktion hood (part 15 here):

So consider what Gruppe M does:

1) it replaces part 15 with something similar but having a scoop at the bottom, wich might be better for directing cold air into the air box
2) it eliminates the stock air box and filter, replaces that with a cone filter that stays in the open
3) it has a heat shield to cover the cone filter.

I am concerned about the fact that the cone filter, although having larger surface area, actually takes air from outside of the engine bay through the stock pipe (15-13-14) as well as from inside the engine bay itself, but even with a heat shield the air will be hotter.

So how much does the scoop do and how much does the cone filter do?

[OC Guy]

Interesting and good questions. Subscribed.