What flows best?: stock intake air box or two small aftermarket filters? in Technical Topics Posted 14 hours ago · Report reply That is almost exactly my idea - but without a corrugated tube - which causes turbulence and restriction. Cooler, slightly denser air produces a bit more power and more cognitive comfort for those of us who over think things. I'm planning to use the smooth silicone hose for car turbo applications. The wall thickness is sufficient that it should never collapse. Also, cutting the air box right where Phil did - at the largest diameter just ahead of the box itself. After that, they neck down quite a bit. Does the air box design trace back to carbs? I haven't searched it yet, but almost think so.