Great 8: Stephen Jeffries Brought This Boosted Mach 1 Back In Style

Great 8: Stephen Jeffries Brought This Boosted Mach 1 Back In Style

If you have ever been involved in a car crash, you know it can be traumatic. That is especially true when the damaged ride is a precious performance machine. Imagine what it would be like if you wrecked a family member’s Mustang. Not only would it be heart-wrenching, but it would leave a lot of guilt in its wake.

When I finally saw it fully complete it was like a weight was lifted off my shoulders. It gets attention everywhere it goes and I couldn’t be more proud… — Stephen Jeffries

That’s just what happened to Stephen Jeffries when he borrowed this 2003 Mustang Mach 1, and the need for speed got the best of him. A car pulled into his lane, Stephen stabbed the brakes, but unbeknownst to him, the brake system pressure was uneven and caused a hard pull to the right — directly into the guardrail.

boosted Mach 1

After crashing his grandfather’s 2003 Mustang Mach 1, Stephen Jeffries bought the car and committed to bringing it back from the brink better than ever. He completely disassembled the car, added a Terminator front fascia and a Shaker hood, then he removed the badges before painting it in Audi Nardo Gray. That sleek finish is accented by dark tint, dark-amber headlights, and a custom, black-brushed aluminum Pony emblem. (Photos courtesy of Stephen Jeffries and by the author)

“This is a redemption story. Six years ago, I was driving it to Cars and Coffee; it was my grandfather’s car at the time,” Stephen said. “The roads were wet, and I was speeding heavily. I lost control and hit a guardrail. I purchased it from him, completely tore it down, replaced the entire front end, and upgraded all components.”

The result is the sleek and stunning Nardo Gray, boosted Mach 1 you see here, but as with any redemption story, it featured a daunting beginning. Eventually, the new owner of the wounded pony car’s determination won out, and this New Edge emerged sharper than ever.

“When I wrecked it, I felt ashamed and was depressed for a bit,” Stephen confessed. “I could have walked away but decided to purchase it. I wanted to prove to myself that I could come out of this on top and rebuild it better than new. The P51 fighter plane was my inspiration.”

Long before the ups and downs of this boosted Mach 1, a young Stephen took a fateful ride in a classic Fox Mustang. Moments like those often cement a passion for these pony cars, and that’s just what happened. Imagine riding in a 5.0-liter Mustang in its heyday and soaking up those classic sights and sounds. It would leave a lasting impact.

Propelling this sharp New Edge is a Four-Valve 4.6-liter engine augmented with COMP Cams camshafts and MMR timing chains. Boosted by a ported and polished Eaton supercharger breathing through an Accufab 100mm throttle body, a JLT cold-air intake, and an SCT Big Air mass airflow sensor, the engine is fed plenty of high-octane by a Lethal Performance fuel system. A dual-pass heat exchanger tames the blower discharge temperatures, while an SVE radiator and fan keep the engine running at its optimal temperature.

“When I was about nine years old, my grandfather purchased a Black 1988 Mustang 5.0 with T-Tops,” he recalled. “I still remember the smell of the interior and the sound of the Flowmaster exhaust. The feeling of hugging the turns around the Dragon’s Tail was such a great memory. Mustangs are my happy place.”

When the time came to get a vehicle of his own, it was only a matter of time before he would put his name on the title of a Mustang. It wasn’t a Fox, however. As he grew into his passion for Mustangs, a new model grabbed Stephen’s attention.

“Since I was a little boy, cars have always been in my blood. My mom, dad, and grandparents have always had sports cars,” he added. “…I am 40 years old. I bought my first New Edge when I was 20. I’ve been hooked ever since.”

It didn’t take long for the sharper styling of Ford’s stallion to convert him to these rides. He was all in once he laid eyes on the alpha New Edge that carried a befitting codename. The debut of the 390-horsepower, Eaton-supercharged Terminator from Ford’s legendary but now-defunct Special Vehicle Team got his heart racing.

boosted Mach 1

Under the rear of the boosted Mach 1, a C2 Rear Diffuser directs the under-car airflow, while a set of ’01 Cobra amber taillights sends signals to those in the rear-view mirror. Anyone with that vantage point can enjoy the symphony of a Roots-blown Modular engine exhaling through MAC long-tube headers, a custom 3-inch exhaust with an X-pipe, and Flowmaster Super 10 mufflers with dual black tips. That exhaust bends off over an 8.8-inch rearend with 4.10 gears and a Ford Performance diff cover.

“What got me hooked on the New Edge was when the ’03 SVT Cobra was introduced,” Stephen recalled. “When the SVT Cobra came out in 2003, I couldn’t get over how smooth/aggressive the lines were, and the more I read about how much went into Ford building the powertrain, the more I fell in love with it.”

With a love for cars from that era, Stephen channeled his passion into revamping this Mach 1, which had suffered extensive front-end damage on that ill-fated ride in the rain. He fully disassembled the car and remade the front end in the image of the New Edge with a ’03-’04 Cobra front bumper with functional brake air ducts and a new hood fitted with a Shaker-style scoop. The whole package is sprayed with the aforementioned Audi hue and ceramic coated for protection.

“Time wasn’t a problem,” Stephen said. “Since the front end was completely gone, the main challenge was starting from scratch with finding a new front end, wiring, and finding/making parts that are no longer being manufactured.”

Under its Shaker hood is a Four-Valve 4.6-liter engine that rumbles to the tune of COMP Cams bumpsticks spinning courtesy of MMR timing chains. The deep-breathing modular inhales through a JLT Cold Air Intake, an SCT Big Air mass airflow sensor, and a 100mm Accufab Throttle body. This high-flow air path feeds a ported and polished Eaton Roots supercharger wearing a 2.76-inch Billetflow pulley that generates ample boost.

Much as the factory intended, the interior of Stephen’s boosted Mach 1 benefits from a full complement of LED lights and a Smart infotainment system with a reverse camera. It also features two AEM bezel gauges. The B&M Ratchet Shifter and B&M shift ball poking through the tunnel actuates a factory 4R70W enhanced with a Max Performance Trans overhaul kit, a Sonnax direct clutch-drum kit, a Boss Hog 3,200-rpm-stall torque converter, and a Hayden transmission coole

With 502 horsepower and 488 lb-ft of torque onboard courtesy of the boosted Four-Valve, a robust drivetrain was required. Stephen selected a rebuilt 4R70W transmission upgraded with a Max Performance trans overhaul kit, a Sonnax direct clutch drum kit, a Boss Hog 3200-rpm-stall torque converter, a Hayden transmission cooler, and a B&M Ratchet shifter with a B&M shifter ball. This prepped trans channels power through an aluminum driveshaft to an 8.8-inch rearend fitted with 4.10 gears.

Putting the power delivered to the rearend to the pavement — via a a quartet of ROVO wheels wrapped in Michelin rubber in front and Toyo R888 rubber in back — is a complete BMR adjustable suspension. That setup includes a tubular K-member, A-arms, sway bars, and a bumpsteer kit up front. Upper and lower control arms round out the package in the back, while UPR adjustable coilovers keep things under control at all four corners.

“It’s an animal that requires respect. It handles like a Porsche 911. The Toyo R888s in the rear and Michelin Pilots in front grip the road like the car is on coaster rails,” Stephen said. “It demands attention while staying neutral in color, and the exhaust — consisting of long-tube headers, a custom X-pipe, and Flowmaster Super 10s — is enhanced with COMP Cams. It sounds amazing at idle and high revs.”

Stephen’s Mach-P51 rolls on a set of black, five-spoke ROVO wheels. They wear Michelin tires in front and stick Toyo R888 tires out back. Those wheels frame Brembo brakes with slotted and drilled rotors.

That sound and performance travel in a handsome boosted Mach 1 that combines some of the most fetching features of the area that are topped with a sleek, gray finish. That complete package grabbed our attention during the Mustang Week 2024 car show and earned a spot in the coveted Ford Muscle Great 8, a single-eliminator contest voted for on the Ford Muscle Facebook page (every Friday until it wraps). So watch for stories on the other Great 8 contestants, and be sure to vote for your favorites.

The winning car owner will score a trip to Mustang Week Texas in April 2025, including a hotel room for four days, a VIP Package including a Golden Ticket (access to every event), a $500 gas card, and $500 for food and drinks. The winner will accept a Ford Muscle Great 8 winner trophy on stage at Mustang Week Texas. The winning vehicle will also be immortalized on a Mustang Week 2025 T-shirt.

Stephen Jeffries’ boosted Mach 1 has come a long way since its unfortunate accident, which is the happy ending to the redemption story he had in mind. “I found that taking my time and doing it right paid off. The first drive from the shop to the body shop to finish up was very emotional,” he recalled. “When I finally saw it fully complete it was like a weight was lifted off my shoulders. It gets attention everywhere it goes and I couldn’t be more proud. I’m so happy with how it all turned out. My friends who made it possible: Ford Master Tech Cody Crago and Jeff Brown at Love & Company Collision.”

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About the author

Steve Turner

Steve Turner brings decades of passion and knowledge in the world of Ford performance, having covered it for over 20 years. From the swan song of the Fox Mustang to the birth of the Coyote, Steve had a front-row seat.
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