5.0 Mustang & Super Fords
2003 Ford Mustang Cobra Terminator
This Snake Doesn't Bare Any Markings, Making It Easier To Surprise Its Prey
When traversing the South, one must tread lightly. Poisonous snakes are pretty common in these parts-especially if your travels take you near Aiken, South Carolina. There you'll likely cross the path of a venomous Sonic Blue Terminator.
Josh Godbee, the keeper of this Cobra, was bitten by the need for a Terminator in 2005. After owning two Mustang GT's and an '01 Cobra, Josh had enough with natural aspiration. But like many, Josh was not fortunate enough to drive off the lot with a new '03 Cobra, so he trolled the used-car market.
"I wanted a Sonic Blue one with chrome wheels, less than 20,000 miles, and a front bumper without license plate holes." Eventually, Josh found one, but the motor was toast. "The timing-chain setup on the left-side head came apart and took out the No. 7 and No. 8 pistons." Not exactly what he had envisioned, but after some negotiation, a deal was made. After an unsuccessful attempt at getting the engine replaced under warranty, Josh decided to go in a different direction.
They started with a VT Engines billet stroker short-block displacing an even 5.0 liters. A set of newer cylinder heads were fastened to the block's deck (the early cylinder heads were known for cooling and valvetrain issues). The dished pistons and combustion chambers combined to yield a supercharger-friendly 8.75:1 compression ratio. With a set of naked heads staring at him, Josh figured a healthier set of camshafts would be appropriate, so Crower's Stage 3 grinds were installed. After the cams were in place and the long-block buttoned up, Josh added the intake and exhaust hardware.
Rather than reuse the factory Eaton supercharger (or even port it), Josh chose Kenne Bell's 2.2L blower. The Twin Screw unit draws through a Billetflow throttle body, a JLT 110mm mass-airflow meter, and a JLT 12-inch cold-air intake. Set up for 17 psi, Josh's new combination had significant power potential, prompting Josh to upgrade the fuel system. He replaced the twin stock fuel pumps with those from a Lincoln Aviator, ran a -8 braided fuel line up to the engine compartment, and connected it to a pair of CPR fuel rails.
Appropriately, every part of the exhaust system was upgraded-starting with a pair of 13/4-inch headers and off-road X-pipe from Kook's, and ending with a Bassani after-cat. The drivetrain received similar attention. The stock clutch came out in favor of a Centerforce DFX unit. Josh fortified the factory T-56 by replacing the notoriously weak 10-spline input shaft with a Liberty's Gears 26-spline unit.
After Josh and his dad were through wrenching, they brought the Sonic Blue Terminator to Amazon Tuning Solutions in Anderson, South Carolina, for the obligatory tuning tweak. Their hard work yielded 649 hp and 570 lb-ft of torque to the wheels on Amazon's Mustang chassis dynamometer.
Though pleased with the numbers, Josh craved more power. In December 2006, he upgraded to a larger Kenne Bell 2.8H Big-Bore supercharger that's pullied for 24 psi. Encouragingly, Josh only read a peak of 19 psi on his Auto Meter Lunar gauge-an indication the engine was flowing more than expected.
To compensate for the added power, Josh strengthened the rearend. From a drag-racer's perspective, the Achilles' heel of the Terminator is its independent rear suspension. Josh discovered his engine's newfound torque provoked the rear suspension to excessive wheelhop. Rather than ditch the IRS in favor of an "old-tech" solid axle, this instrumentation and controls engineer took a systematic approach to beefing up his IRS. The source of wheelhop is flex in the rear suspension components, so Josh's modifications focused on eliminating slop. Josh replaced the soft rubber OEM pieces with polyurethane subframe and differential mount bushings, and welded BilletFlow IRS mount support brackets in place. Before he put the welder away, Josh stiffened the toe control links with lengths of 3/4-inch OD 16-gauge steel tubing.
Fortunately for Josh, the previous owner already installed a 4.10:1 rear gear set. Though stronger than the early '99 and '01 Cobra halfshafts, Josh figured the factory '03 Cobra axles wouldn't survive, so he replaced them with a pair of The Driveshaft Shop's Level 5 halfshafts with chrome-moly inner CV joints. Josh didn't ignore the other driveshaft, as he replaced the OEM aluminum piece with a carbon-fiber unit. Finally, to "keep the pumpkin's guts inside" when launching on his 315/35-17 M/T drag radials, Josh added a Steeda differential cover brace.
Up to that point, Josh's best quarter-mile times were a few 12s at over 122 mph-launching at idle on street tires! With more power than ever under the hood and heavy-duty hardware throughout, Josh was ready to see how quickly his Snake could slither. At an SVT drag day, Josh got his chance. Shoe'd with his sticky Mickeys, Josh nudged the Cobra to the starting line and brought the revs to 4,500. When the tree went green, Josh dumped the clutch-but instead of launching, the Terminator snapped one of the halfshafts in half! What a letdown!
Josh replaced the broken axle, but at the time of our photo shoot, he was waiting for a few other parts before he could re-dyno the car and attempt another run through the quarter-mile gauntlet. A Fore Triple Hat with three Ford GT fuel pumps, an octet of FRPP 80-lb/hr injectors, and a Modular PowerHouse supercharger inlet were recently added.
Unfortunately, these additions made Josh's Cobra so temperamental, it wouldn't even idle. After spending months unsuccessfully diagnosing the problem, Josh was fed up. He considered selling the car. Fortunately, Eric Brooks of Brooks Speed came on board and was able to tame Josh's potent combination.
Drinking 93-octane pump gas and breathing 19 psi, Josh's Snake spit out a solid 704 hp and 662 lb-ft of torque on Brooks Speed's Dynojet
With so much venom beneath its subtle skin, Josh's Cobra strikes ferociously when provoked. So if you're in town, you better watch where you step.
5.0 Tech Specs
Engine and Drivetrain
Crankshaft VT Engines forged, 3.750-in stroke (302 ci)
Rods VT/Oliver forged billet
Pistons VT/CP forged
Camshafts Crower Stage 3
Power Adder Kenne Bell Twin-Screw, 2.8-liter H Big-Bore supercharger, 19 psi
Cylinder Heads OEM, Jan. '05-later
Intake Manifold Stock
Supercharger Inlet Modular PowerHouse Behemoth
Throttle Body Billetflow
Mass Air JLT Performance 110mm and cold air intake
Fuel System Fore Triple Hat with 3 Ford GT pumps, Aeromotive in-line filter, -8 supply line, CPR fuel rails, FRPP 80-lb/hr injectors, 93-octane pump gas
Exhaust Kooks 1 3/4-inch full-length headers, Kooks X-pipe, Bassani after-cat
Transmission Stock Tremec T-56, Liberty's Gears 26-spline input shaft, MGW shifter, 10th Anniversary Cobra shift knob
Rearend 4.10:1 gears, Steeda differential cover brace, Maximum Motorsports differential mount bushings, The Driveshaft Shop Level 5 halfshafts with chrome-moly CV joints
Engine Management Stock EEC-V with Brooks Speed tune
Gauges Auto Meter Lunar boost and fuel pressure, Dynojet Wideband Commander, SOS pillar gauge pod
Chassis and Suspension
Control Arms Stock
Caster/Camber Stock with SN-95 covers
Control Arms Stock with Steeda subframe bushings, modified toe control links, Billetflow IRS support brackets
Wheels American Muscle 17x10.5-in chrome
Tires Mickey Thompson 315/35R-17 ET Street Radials
chassis stiffening Kenny Brown subframe connectors