[jks327]

I was wondering if anyone out there has ever tried drilling holes in the front side of a stock bmw airbox [obviously below the filter and in a way that wouldn't let anything bad into the airbox]. It seems that this would increase airflow without replacing the stock unit. If anyone has tried this or seen it tried, i'd love to know how well it works or if it works at all.

 

[TCM]

This would not increase the airflow to the box as it would just be getting hot humid air from under then car's hood if anything at all. You are better off rerouting the stock air tubing to get cool air from outside the car into the stock airbox like the AA setup. It works very well on all the 5 series (we have done similiar intakes on many at the shop). Hope this helps.