At what point does it become a restriction? I have a drop in K&N filter in it. I understand it pulls cooler air from the front vs a cone style filter. I am running OBX headers, 2.5 full exhaust with Borla mufflers, Comp xe258 cam, stock gt40 heads, Explorer intake with ported lower, 5 star 87 tune. Would a cone filter bolted directly to the mass sensor gain me anything?