 With Jim D'Amore of JDM Engineering...  With Jim D'Amore of JDM Engineering doing the driving, we took a stock '06 Mustang down the quarter-mile to a best of 13.84 at a bit over 97 mph. Not bad for a stock Stang riding on 20-inch Weld wheels. |
 Pop the hood on any new Mustang...  Pop the hood on any new Mustang GT and you will see the same thing we saw: a 4.6, 300hp, mod motor. The stock airbox fits perfectly against the left-front fender. With the stock inlet system, the inlet air temperature was measured at 93 degrees, well above the 67-degree ambient-air temperature present when the car went down the track. |
 The three kits tested were...  The three kits tested were the AEM Brute Force (left), the Western Motorsports (WMS) High Velocity (center), and the Steeda High Velocity (right) cold-air kits. The Steeda and AEM kits were similar in design and were easy to install. The WMS kit was more involved. |
 With the AEM kit bolted on,...  With the AEM kit bolted on, we took a few trips on the track to see how much it gave us. The car picked up a few hundredths of a second over the stock setup, running a 13.831, 97.79 best. Of note is the change in air conditions from the baseline test. The 200-foot increase in DA hurt performance a little, costing us around a hundredth of a second in e.t. and a bit of speed. We also believe the kits would be more effec-tive on a mildly modified Mustang as opposed to a dead-stock one. |
 Jason Bowe from JDM removed...  Jason Bowe from JDM removed the stock inlet system. The airbox unbolted from the brackets on the fender, and the hose clamp was undone, allowing the inlet tube to come off the throttle body. Before pulling everything out, he remembered to unplug the MAF sensor. |
Ram-air induction has been a part of hot rodding for decades. In the '60s and '70s, factories experimented with all types of ram-air or cold-air packages because providing fresh air to the engine, rather than hot air from under the hood, increased power (and it looked pretty cool, too). Some scoops just guided air toward the carburetor, while more elaborate systems were sealed to the air cleaner and carb assembly. Systems ranged from the under-the-bumper scoops found on '69 Oldsmobiles to cowl-induction and Shakers that stuck through the hoods of Mustangs and other popular models. Ford, GM, and Chrysler learned long ago that feeding cold air, or more accurately, fresh air, to the engine definitely works.
In the '80s, Ford used a fresh-air system on its V-8 Mustangs and a similar system on the '86-present injected Mustang, which drew air from the inner fender area. The aftermarket took this design a step further and offered kits that extended the entry point from the inner fender to a more advantageous location. This meant either a headlight was removed or the scoop went under the bumper.
Using the headlight la the '64 Thunderbolt worked great for the track, but it wasn't practical to ride around with a headlight missing (though many did just that). On the other hand, placing the scoop down low was also controversial because while it could feed the engine fresh air, a low scoop picked up water, leaves, and other road debris. No doubt, more than one engine was lost due to foreign matter getting to the cylinders.
Today, cold-air kits are still the rage, but there is controversy over just how effective these systems are, specifically on '05-'06 Mustangs. Do cold-air kits really work, and, if so, how much power can be gained from using them? Sure, we've seen many of the kits gain 10-15 hp on the dyno, but what does that mean on the track? Additionally, how hard are they to install, and is tuning required?
To learn more, we decided to skip the dyno, grab a few kits, and head to the track. Our tester was an '06 Mustang GT equipped with an automatic for consistency's sake. We got our hands on AEM's Brute Force kit, which simply bolts into place with no tuning and sports an open-element underhood filter and sweet-looking inlet tube. We also bolted up Steeda's easy-to-install kit, with tuning provided, and, lastly, a trick design from WMS that grabs fresh air from the grill rather than from underhood. Of course, there are many more kits on the market, some which work fabulously, but these represented what we wanted for this test.
Baseline NumbersFor the cold-air trials, we used the previously mentioned '06 Mustang GT generously handed over by the crew at JDM Engineering, the only change being the huge Weld Racing 20-inch rims wrapped in Pirelli rubber. The plan was simple: eliminate as many variables as possible and chart what happened when we strapped on each cold-air kit. After a few test hits at Old Bridge Township Raceway Park, it was determined that even with the street tires, there would be no tire spin at all. We had stickier tires just in case, but they weren't needed. Jim D'Amore from JDM handled the driving and launched at a consistent 1,800 rpm on every run. Thanks to a PerformAire weather station, weather conditions such as temperature, humidity, and barometric pressure were monitored before each set of passes. All of these factors were computed by the weather station to come up with the density altitude (DA), which we also monitored. Additionally, the transmission temperature was kept between 200 and 205 degrees, the water temperature between 194 and 198 degrees, and the oil temperature between 193 and 197 degrees. The air/fuel (A/F) ratio was monitored with a Horiba A/F meter. By keeping all of the perimeters in check, we could accurately gauge changes to the inlet air temperature (IAT) and the elapsed time and mph, which would be the hard evidence.
The first set of passes gave us our baseline numbers, as the Mustang was run with the stock airbox. With a DA of 1,434 feet above sea level, the Stang clicked off a 13.858 at 97.28 mph. The second pass was practically a carbon copy, resulting in a 13.842 at 97.13. Heat soak set in for the third pass as the car slowed down noticeably to a 13.939 at 97.25. The IAT was measured at 93 degrees, and the A/F stayed at 12.5 consistently. Sixty-foot times ranged from 2.09 to 2.10. With our baseline numbers gathered, it was time to break out the wrenches and get down and dirty.