On the left is the new 80mm, billet WMS mass-air housing and the factory's tube is next to it. The physical difference between the two (shape/diameter) is obvious. However it's important to note that overall, the WMS high-velocity intake is not larger than the stock system. According to engineers at Western, with the two setups being so similar in size, air/fuel ratios do not become leaner with the High Velocity and ram-air pieces, so tuning is moreso an option than a must-do task (a DiabloSport calibration for the system we tested can be purchased separately). The stock sensor is transferred into the new mass-air housing using the supplied T-20 Tork screws; the original PCV air tube snaps into a billet adapter that sits in the tube-to-throttle-body urethane coupler.