Ive experimeneted with an number of setups, all this cold air tubing stuff is gimmicky.IMO all it does is cause the air to be more turbulent and travel al longer distance. DIY is not gonna work the same as professinaly built. The setup im using now is no cold air extension, I just cut the inlet whole to the airbox bigger and droppin a KN filter. The stock airbox design sucks up cooler air regardless, if you look at the airbox it shields the inlet whole from the engine bay heat and the inlet whole sucks up air from down through the fender through the whole leading to where the resonator used to be.