Has any body ever test to see how far the stock air box and filter can go? I ask because the diesel guys say there's are good to the 500hp mark. And they filter dirt way better than cloth stuff. So if one could do say 500. Then one a piece on two turbos might could do 900 or so?

 

i saw a 4 hp difference in a 4x10inch k&n filter, make 1110rwhp without it, and 1106 with it on.

 

i'm looking more into twin ac delco fliter setup like off a dmax.