Twin Turbocharged 2004 Ford Mustang Cobra - Mystichrome Terminator

Terminator was Ford's internal code name for the in-development '03-'04 Cobra. These supercharged Snakes are popular, but not because of that nickname. The Cobras are fast, and easily become faster. With such easy horsepower gains from bolt-on parts and upgraded power-adders, the slippery slope to power madness is an easy one to slide down. Jamey McClellan of Borger, Texas, did just that when he took his '04 Cobra to what he calls "a whole new level of seriousness."

Like many other Mustang fanatics, Jamey has owned a stable-full of Ponies since the early '90s, ranging from his first, an '85 Mustang GT, which he still owns and races, to several Fox-body GTs, LXs, and an S-Trimmed '96 Cobra. The Mustang that really got his attention was the '04 Cobra in Mystichrome. The fusion of cobalt blue, topaz green, royal purple, and onyx black mesmerized the young man five years ago at the Mid-America Ford and Shelby Performance Convention in Tulsa, Oklahoma. While walking around a convertible version of the car at least a dozen times to watch the colors change, he knew he had to have one.

When he realized that dream, the modifications began immediately. Jamey learned of Stiegemeier Engine Airflow in St. Charles, Missouri, which ports superchargers, like the Eaton on the '04 Cobra. "If a customer could spin a dyno up to 500 hp with one of the company's port jobs on the '03 or '04 Cobra," Jamey says, "Stiegemeier would send out a free T-shirt."

Jamey took them up on this offer for extra power and the chance to enhance his wardrobe. After porting work and with the addition of a Mac Pro Chamber, Magnaflow after-cat, K&N FIPK, 2.93 upper pulley, 4-pound lower pulley, and a custom tune, the 4.6-liter DOHC turned in dynamometer results of 550 hp and 560 lb-ft of torque. Needless to say, Jamey scored a new T-shirt. A week later, he gave new meaning to the term Terminator. He burned up the No. 2 piston in the 4.6-liter.

Jamey blames himself for the meltdown. The EGR lines that flow back into the inlet on the supercharger ingested motor oil and killed the fuel's octane. Denotation burned up the motor. Jamey should have installed an oil separator, which acts as a trap to extract the oil mist out of the EGR lines. He was looking to rebuild the stock Cobra motor when he came across Jim Napier of Turbo Horsepower in Albuquerque, New Mexico.

"He offered me a deal I couldn't refuse on a Modular Mustang Racing-built Lincoln Navigator, DOHC, 5.4-liter V-8. After I bought the engine, we started talking about turbo combinations," Jamey explains. With 50 additional cubic inches over the Terminator's stock 4.6-liter and twin turbochargers, Jamey figured he had a shot at a 1,000hp street car. This was his new goal, this time without the incentive of another T-shirt. Asked why he set the bar at 1,000, Jamey answers, "Why not?" Indeed.

After the supercharger adventure, Jamey was seemingly excited to try turbos. He called them "the most efficient power-adder on the market, with no bottles to refill or blower belts to slip." This time, he made sure to install breathers to keep the oil far away from entering the combustion chambers. Jamey learned this lesson the hard way with the blower. At 10 pounds of boost, the 5.4's first dynamometer run yielded 679 hp and 596 lb-ft of torque at the rear wheels.

Of course, that was well below his goal. In search of bigger numbers, he started climbing the boost ladder from 18, 19, 21, and finally 22 psi. At around 21 psi, the twin-turbo 5.4 experienced difficulties with the spark blowing out. The engine didn't die; it would fade off. In the graphs, the big modular showed a smooth curve in the horsepower and torque until the rpm approached 5,500. At that point, the skyrocketing horsepower and torque curves became erratic, indicating the loss of spark.