Most interesting was no air filter made no power gain vs using an standard factory air filter. Makes you think twice about those K&N claims we all seen. Fascinating stuff.
Yet these guys dyno tested a ~400hp mopar big block and found a 14hp difference between a generic 3" paper air filter in an open element air cleaner versus open carb. Clearly these results would vary with engine air intake demands as well as the efficiency of your existing air cleaner, but the filter they used for their dyno testing was pretty standard in the hot rod community.
