645 RWHP, Compound-Turbo, 4.6L, 4V, '03 Mustang Cobra
Jeff Van Buren, Waterford, NY
Unless you've been digging to China since 2003, you've heard the slide-whistle shriek of a Whipple-charged 4V 4.6L Mustang Cobra as it gently suggests you move to the right. The Terminator Cobras were rated at 390 hp from the factory, but everyone quickly figured out that 500 rwhp could be had with a pulley swap and basic bolt-ons.
The idea of compound boost has also been around for a while, so when Jeff decided to combine the chocolate and peanut butter, he got this road monster that makes an easy 600 to 800 hp on pump gas, depending on the tune. The twin-turbo kit is offered by Hellion Power Systems in Albuquerque, New Mexico, and is capable of producing up to 1,200 hp with race gas. Check out the company's new '10 to '11 Camaro system and Mopar systems, too.
Tucked behind the front bumper is a pair of Turbonetics 61mm turbos from the Hellraiser kit. Together, these suckers can belt out a streetable 800 hp on pump gas. There is also an upgrade to 66 mm to make 1,000 if you want to go racing.
Boost is fed into the recessed air-to-air intercooler then into the supercharger via the pipe you see in the photo. The Eaton feeds the air into the factory air-to-water heat exchanger then into the manifold. For more than 800 hp, the guys at Hellion recommend using a water/methanol kit as well.
The 34mm blow-off valve is made by TurboXS.
The major difference between the stock MAF and the one seen here from SCT is the metal housing that won't crush when you put a clamp on it.
Jeff's Mustang uses a stock computer tuned using a SCT-X-CAL3 handheld flash tuner to get the A/F ratio and timing curve right.
F. Throttle Body
The efficiency of the turbo allows the stock throttle body to be used. Larger units show little improvement.
The Eaton supercharger uses the stock pulley. The turbos do all the work.
To feed this kind of power, Jeff used three Walbro fuel pumps mounted in tank, upgraded the lines to -8, and added a larger fuel rail and an Aeromotive regulator.