What is the difference between a cold air intake and a short ram system?

A cold air intake system uses the vehicle's existing air intake manifold system to work properly. It not only adds a larger-sized air intake but it will also likely include an intercooler system that will help keep the fuel-air charge cool and dense which is the best formula for power output. A short ram system relies on a hood scoop and direct input of cold air into the intake stream. The ram air effect is due to the fact that the hood scoop uses a decreasing or venturi system to raise the pressure of the fuel-air charge but it is almost instant and there's not much plumbing involved.