Cobb - intake required for stage 2
So we all know that to run Cobb stage 2, it is a requirement to have an upgraded intake. And I have also been informed that a drop-in filter will suffice as an "upgraded intake".
The thing is, there are numerous threads not just debating the performance increase of an aftermarket intake (DCI, CAI) to stock box, but also drop-in filters to the OEM paper filter. These threads (with testing) show negligible gains in performance.
So the question is, if there is not much performance gain with an aftermarket/upgraded intake, why does Cobb state it to be a requirement to 'upgrade' the OEM intake whilst using stage 2?
I know I'm probably missing something really obvious here, but I just can't see it. Thanks for schooling me.