That's an arguable topic. The filters in their factory location were constantly heated. Any cool air coming into the intake is then heated by the filters (acting as heating elements). Putting the filter outside of the engine bay (or placing a shield around it) isolates that problem. Filter outside sucks in cooler air, there are no longer any baffles to slow it down so the air getting to the supercharger technically should be cooler. How much? That's a good question.