2005-2006 Mustang Cold Air Kit Purchase - Conscious About Cold Air

After the install was complete, it was time to let the Mustang rip with the new kit and the stock tune. With an altitude of 1,941 feet (ASL), the air was nearly the same as it was when we tested the Steeda kit. The first run netted a 13.871 at 97.40. That pass was backed up with a 13.908 at 97.30, and the final run of the series was a 13.838 at 98.13. The kit, in stock form, lost e.t. on the first two runs, but the final e.t. was comparable to the e.t.'s from the other two kits. The trap speed was also comparable to that of the other two kits. The major change with the WMS kit was the IAT dropped significantly to 77 degrees. Obviously, because air enters from the grill, and the air filter is located above the radiator, the result significantly lowered the temperature of the incoming air charge. While that should have led to some increase in power, the track times showed the same numbers as the other two kits with higher IATs. So, with the stock tune not showing any difference from the other two kits, would the tuned version of the WMS kit wake up the stock S197 GT?

After taking a few minutes to load the accompanying tune-up and change to the larger inlet tube, the test mule was ready to take another stab at the Raceway Park quarter-mile. The DA skyrocketed to 2,366 feet, but the car ran its three best passes of the day with the tuned WMS version. The first run ended after 13.694 seconds, with a trap speed of 98.48 mph. The second run was 13.699 seconds at 98.68 mph, and the final run was over after 13.784 seconds with a terminal velocity of 98.48 mph.

The IAT was once again recorded at 77 degrees. Of interest, however, was the change in 60-foot times with the WMS tuned kit. The last three runs showed 60-foot times of 2.06, 2.07, and 2.09 seconds, respectively. These three short times were the best of the day, bettering the stock 60-foot times by a few hundredths and the 60-foot times seen with the other two kits by nearly a tenth of a second. With the WMS tuned kit, the A/F ratio hovered around 12.8-12.9 during the three runs.

ConclusionAfter all was said and done, the test results showed the importance of getting cooler, fresher air into the engine. Starting with a stock IAT of 93 degrees, each kit showed lower IATs, which directly related to the power gains seen on the track. Of note is the continual increase in the DA during the day. While the DA was lowest while testing the AEM kit, the Steeda kit ran under a DA almost 200 feet higher and the WMS kit ran with a DA that was almost 1,000 feet higher. With this increase in altitude, the air going into the engine was slightly worse, thus cutting down on the true power output. Every time the DA increases, the e.t.'s worsen and the speed is down correspond-ingly. Normally, for every 150-foot change in DA, a naturally aspirated car will lose about a hun-dredth of a second in elapsed time.

While these kits are good for at least 10 hp, is there a huge difference in how the car runs after the kit? While 10 hp may or may not seem to be a lot, it is normally good for about a tenth of a second and 1 or 2 mph at the track. The other thing we must discern is whether or not the kits work better with or without a tuning program. According to Sam Cory of Steeda, using a tuner with a cold-air kit can increase the productivity of the new parts.

"I've seen the other kits sometimes work without a tuner, but what it comes down to is when you put on a cold-air kit, the car is lean," Cory says. "If you are going to make any serious type of horsepower, the car will go into failsafe mode and not run."

"Whether the car needs a tune or not depends on the kit," says Shannon Wall from Western Motorsports. "Our 80mm kit doesn't have a tuner included with it and it runs well. With a programmer, however, the car can obviously make more power."