Originally Posted by Nebster
the stock BMW airbox is very well engineered. I'd like to give the ultimate racing CAI a shot but if the filters are going to stay in the engine bay they need to be enclosed. The best solution might be a drop in filter.
I've run the UR CAI for quite awhile. It really is one of the best out there.
If the AFE supposedly loses 20hp that's something you would definitely feel. I don't know about that much, might be a bit of a stretch.