KJ Jones Senior Technical Editor
June 1, 2009
Saul "The Surgeon" Gutierrez of Extreme Automotive pushes Western Motorsports' high-velocity intake pieces into place on a bone-stock, low-miles, 4.6-liter engine in an '06 Mustang GT. We're evaluating WMS's unique center-mounted CAI upgrade, which features a cool tray-like ram-air box that routes cold air in a straight shot from a Mustang's grille directly into the oval-shaped filter, mass-air housing, urethane coupler, and throttle body.

Cold-air-intake systems arguably have been the most popular bolt-on upgrades for S197 ('05-present) Mustangs since the cars became available nearly five years ago. It's amazing how quickly time has passed.

In that half-decade, we've reviewed different CAI systems and discussed the concept and principles behind diverting cooler air into a late-model 'Stang's Three-Valve engine. In a nutshell, aftermarket air-intake setups promote improved performance by drawing in higher volumes of ambient air (compared to OEM filters and tubing alone) from beyond the confines of a 'Stang's engine compartment. Greater air density and the increased volume that CAIs generate accelerate fuel atomization, which creates a hotter explosion inside the cylinders and produces more horsepower.

Although there certainly are visual similarities between many of today's popular S197 cold-air systems, it really is unfair to refer to them all as "the same." Each system includes (oftentimes subtle) differences in their design (tubing curvature/airflow and materials) and operation (requires/doesn't require additional engine tuning) that have varying effects on '05-'09 stock or modified 4.6 Three-Valve engines.

A stifling airbox and obscenely inefficient inlet tube (check out that elbow just before the throttle body) are the primary fault areas in S197s' OEM air-intake system. Although many new enthusiasts are quickly learning about the poor quality of this design, we can't stress enough that these pieces should be replaced-sooner rather than later. In preparing for installation of the WMS system, Saul removes this factory equipment as a unit, as well as the test 'Stang's original radiator cover, which will be replaced by the new ram-air box.

Western Motorsports' High-Velocity Intake and Ram Air box (PN WMS-HV105R; $479), a direct-flow CAI for S197 Mustang GTs (High Velocity Intake kits also are available for V-6 Ponies), is our test product for this month's Tech Inspection.

The immediately noticeable highlights of the WMS cold-air setup are its ABS-plastic ram-air box (it's actually more like a tray that's enclosed once the hood is shut), which replaces the radiator cover in a Mustang's engine bay, and a cool oval-shaped, billet, 80mm mass-air housing that sits front-and-center in the box. This unique front-mount design takes advantage of the trey-valve's forward-facing throttle body, allowing cold air to channel directly through the grille instead of using a long inlet tube that curves off to the corner of the engine compartment, and directly replaces the factory airbox (similar to the way most CAI kits are positioned).

While we were given the option of testing a WMS intake system that requires tuning (the tuner system uses a 95mm mass-air housing and SCT program, and should be used on modified S197s), we thought it better to evaluate Western's "non-tune" intake system, for those enthusiasts with stone-stock '05-'09 'Stangs who are considering intake-air alternatives that don't alter the factory's PCM settings.

The 'Stang's factory coolant overflow reservoir requires relocating, and Western Motorsports provides the bracket, hoses, clamps, and clips that are required (there's no drilling necessary for this procedure) to make it a simple deal. After draining the coolant, Saul positions and secures the jug on the driver-side front fender; then attaches the new feed and return hoses.

Saul "The Surgeon" Gutierrez of Extreme Automotive in Canoga Park, California, is helping us with the High Velocity Intake unit's simple installation-a do-it-yourself enthusiast can do this in about two hours with handtools-and evaluation of the before/after dyno results on an '06 Mustang GT that was at the shop for service.

Baseline WMS Difference
2,{{{200}}} 109.40 255.38 112.39 264.29 2.99 8.91
2,400 116.28 251.70 120.67 261.01 4.39 9.32
2,{{{600}}} 127.70 253.42 132.69 263.51 4.99 10.10
2,800 139.04 256.39 144.49 266.32 5.45 9.93
3,000 149.58 257.86 154.08 266.71 4.51 8.84
3,200 160.31 259.13 163.{{{80}}} 265.37 3.50 6.24
3,400 173.55 264.05 174.95 265.59 1.40 1.54
3,600 188.13 271.51 188.83 272.50 0.70 0.99
3,800 202.93 276.65 207.65 283.59 4.72 6.94
4,000 216.51 280.64 220.96 286.69 4.45 6.05
4,200 231.96 285.33 233.13 288.38 1.17 3.05
4,400 242.74 286.80 247.{{{62}}} 291.82 4.89 5.03
4,600 252.64 284.31 258.27 290.02 5.63 5.71
4,800 259.95 280.37 265.63 286.05 5.67 5.68
5,000 265.92 275.66 270.34 282.43 4.42 6.78
5,200 269.89 266.98 278.14 277.23 8.25 10.25
5,400 268.75 258.33 280.66 269.81 11.{{{90}}} 11.49
5,600 265.03 245.08 279.29 258.19 14.26 13.12
5,800 262.86 236.90 278.32 250.61 15.46 13.71
M5lp_0906_06_z Cold_air_intake_systems_for_s197_mustangs Wiring
Due to the mass air's new position immediately in front of the throttle body, the sensor's wiring harness must be lengthened. WMS provides the wire that is necessary for this task, and Saul uses solder to ensure the connections are solid and permanent.
M5lp_0906_07_z Cold_air_intake_systems_for_s197_mustangs Ram_air_box
Western's ram-air box assembles quickly (a flat surface is required), as it only involves securing two borders (included) to the backside edges of the kit's ABS plastic tray. Each border is held in place with two-sided adhesive, as well as small screws. Once assembled, the ram-air box is placed in the radiator cover's original positioned and secured with factory fasteners.
M5lp_0906_08_z Cold_air_intake_systems_for_s197_mustangs Mass_air_housing
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.
M5lp_0906_09_z Cold_air_intake_systems_for_s197_mustangs Completed_cold_air_intake_system