Muscle Mustangs & Fast Fords
2003 Ford Mustang Cobra - A Lot For A Little
Twin Turbos Boost HPP Racing's Cobra To 820 RWHP On An Internally Stock 4.6.
Those smug LS1 boys didn't know what hit 'em. Overnight, SN-95-the platform made famous for pairing an Eaton blower with the four-valve-per-cylinder mod mill-made for a lethal combination with crazy potential. Although the '03-'04 Cobras were often ridiculed by the Bow-Tie crowd, Ford's last Cobra was one bad mofo. Aptly dubbed the "Terminator," it pushed stock SVT Mustangs deep into the 12s despite a suspiciously conservative horsepower rating of 390. Simply swapping in a smaller blower pulley and uncorking the intake and exhaust tracts had Cobras laying down 500 hp at the wheels. The LS1 was finally subjected to a paternity test, and its daddy was the '03 Cobra.
While comparisons between Fords and Chevys are inevitable, perhaps the Cobra is more of a domestic rebuttal to the Toyota Supra. Like the Toyota's 2JZ-GTE inline-six, the Cobra's bulletproof long-block can handle hundreds of additional horsepower without breaking a sweat. Its stout iron block, steel H-beam rods, and forged crank and pistons laugh in the face of extra boost, but there's still a point where the stock Eaton gets wheezy. To push the boundaries of the stock 4.6 to the max, Manny Alvarez of HPP Racing (Lewisville, Texas) yanked the factory blower in favor of twin GT35R turbos. The result was 820 rwhp.
As impressive and Supra-like as those numbers may be, Manny set out to build a car that could actually run hard at the track, not be just a dyno queen. The first step was finding a suitable project car, but with the short, two-year production run of Terminator Cobras, Manny couldn't find one locally. He won an eBay auction for an '03 Cobra-sight unseen-with just 6,000 miles, and hoped for the best. "Luckily for me, the seller was honest and the car was in perfect shape," he says.
That gamble may have paid off, but Manny didn't want to take any chances in the horsepower department. For assistance in fabricating the twin-turbo setup, he turned to Pro Turbo Systems (San Antonio, Texas). The two shops bounced ideas off each other, and PTS built the turbo kit to HPP Racing's specifica-tions. The system features 151/48-inch forward-facing headers, two 60mm turbos, and 3-inch downpipes. Compressed air is then chilled in a front-mount intercooler before dumping into an Accufab monoblade throttle-body, a custom sheetmetal plenum, and a Sullivan intake mani-fold. Fueling the monster is a Weldon 2345 pump and 75-lb/hr injectors, and James Vicars of HPP tuned the stock computer using an SCT chip. Although packaging twin turbos may seem like a nightmare, the HPP kit is surprisingly space efficient. Granted, an aftermarket K-member (Manny runs a D&D piece) is a must to free up space, the battery and power-steering assembly are the only parts that need to be relocated. The A/C stays put along with all other factory accessories.