When I changed to larger injectors, the engine experienced very high egt's with the stock air box and filter, I tried one of the high flow/high performance drop in filters similar to the K&N but a cone filter and I still had high egt's. I replace the OEM air box with a BHAF and Outterware's Prefilter and experience a significant drop in egt's (still not all I needed). The installation of the Farm Boy Performance 5 inch tubo back straight pipe exhaust addressed the remaining egt issues and enhanced drivability substantially. Together they made a HUGE improvement. The BHAF has a HUGE increase in filter media surface area over the OEM filter. I would venture a guess as to something close to double the amount. Air flow performance should commensurately increase.