Muscle Mustangs & Fast Fords
Supercharged Zex Appeal
It's Boost Versus Juice For This Tale Of A 2004 Cobra Terminator
Count me as one of the many who are very excited about the new 5.0 Coyote engine. Even if the best thing about it was the 5.0L name (I still have a soft spot for the original), the new motor would be very popular.
Lucky for Ford fans, the Four-Valve 5.0 is much more than a successful marketing ploy. Trick intake, variable cam timing and Chevy-topping performance (thanks no doubt in part to a lower curb weight), the new Mustang is an impressive piece indeed. If there is one complaint, it is the lack of forced induction. I know the Shelby GT500 is blessed with a blower, but I can't help wonder if, and when, we might get a supercharged 5.0.
Given the success of the Ford Racing Aluminator engine program, we should at least see low-compression versions of the Coyote available through the FRPP catalog. As great as the new 5.0 motor is internally, it still doesn't quite match the (seemingly) underrated Terminator motors offered from '03-'04. The supercharged 4.6L offered not only serious factory horsepower (and more importantly torque), but the ability to digest massive amounts of boost. Credit factory forged internals, topped by free-flowing cylinder heads and factory forced induction for the serious power potential.
We all know and love the '03-'04 Cobra motors. There is nothing quite so satisfying as having immediate boost followed by a surge of torque that accompanies a positive displacement supercharger. Impressive even in stock trim, the factory tune was purposely conservative, which meant there were bucket loads of power left on the table. Add a splash of good fuel, a more aggressive tune (altering both air/fuel and timing), and a few extra pounds of boost, and you had one pleasingly powerful Pony. In fact, the motor was so capable that eventually, the supercharger itself became the limiting factor in terms of maximum performance.
In all fairness to the Eaton Roots blower, it was never sized for 700-plus-horsepower, but the rest of the motor certainly seemed to be. Having pushed these factory engines well into the four-digit power territory, we can safely say Ford blessed these motors with a sizable safety margin. With this margin in mind, we ventured down two different paths in an effort to realize that potential.
The most obvious path was to maximize the existing supercharged combination and then add a dose of chemical warfare. The idea for round one was to take a stock '04 Cobra motor, crank up the boost on the Eaton supercharger and then hit is with a small does of nitrous oxide. In truth, we could have run considerably more nitrous, but the effort does illustrate the potential of the combination of boost and nitrous. Both are great at improving power production separ-ately, but combined they are even more formidable. The supercharged, Four-Valve test motor came from an '04 Cobra that had plenty of power, but as it turned out, very little talent behind the wheel. Crash damage destroyed a perfectly good Camaro killer, but the motor was still factory fresh.
Naturally, we were going to run this motor at a level higher than stock, but we also wanted to limit our modifications to external bolt-ons. With forged internals and free-breathing heads, the only thing missing (in our mind) was a set of performance cams. Tempting to be sure, we nonetheless resisted the urge to even remove the valve covers, and instead concentrated our attention on boost and juice.