ive started a thread discussing air filters and the verdict with that is that air filters and smoother air intakes don't really help.
http://ecomodder.com/forum/showthrea...ota-31397.html
but now you say it does help to get more cooler air in? my airbox sits on top of the motor and I wonder how it baking in that heat effects it? I like what you did with that pipe insulation I am going to try the same with foil tape.