Muscle Mustangs & Fast Fords
A Pony's Performance Evolution
From no motor to four, this Ford's engine bay has seen it all.
The rolling chassis. To most, it's just a pile of metal waiting to take that final journey to the scrap yard. For hot-rodding types, it's a blank canvas on which to paint a palette of Pony pigments.
When we ran into Middletown, Delaware's Matt Lepkowski and his '83 Mustang at the inaugural Garden State Fun Ford Weekend, we were impressed with the clean and muscular look of his four-eyed Fox-body. Little did we know it had come a long way since Matt first purchased it 10 years ago minus motor and trans.
"The car had no drivetrain, but the interior was in good shape," Matt says. "I really wanted a Mustang, and the price was right." The initial investment in the project supplied a carbureted 302 topped with '70 351 Windsor heads and a C4 automatic.
"The 7.5 axle broke on the first pass, so I just skipped the 8.8 and went right for the 9-inch," Matt says. Moser axles and 4.10 gears fill the housing out back and have endured everything Matt has thrown at it since.
The little 302 was good for 12.70s, but a 351 Windsor soon found its way between the shock towers. "It was as budget as budget gets," Matt says. "The rods and crank were stock, and I used a set of $130 forged pistons in the bottom end." The heads were borrowed from the 302 and the engine was stuffed with a solid roller camshaft. The Pony charged to the 12.30 range, and the addition of Edelbrock Performer RPM heads dropped the elapsed times further, to 11.90s.
Then came the juice. One hundred and seventy-five horsepower worth knocked the hatchback into the 10-second realm with a best time of 10.35. After about 150 nitrous passes, the 351 tapped out-catastrophically, we might add.
Motor number three was a siamese-bore SVO block packing a Sonny Bryant crankshaft and Carrillo connecting rods. Combined with a set of Twisted Wedge R-series heads, the 373ci mill muscled the Mustang down the 1,320 to a 10.82 elapsed time, naturally aspirated.
Then came the juice again-and the track officials. It seemed they weren't happy with Matt's level of safety equipment after his little freak scooted to a 9.91 at 137 mph. As great as the achievement was, it was a wake-up call to Matt and a time to evaluate what he really wanted to do with the '83.
He still cruised the car on the street, as it has been tagged and insured since the project began, but installing a full rollcage and a window net, and getting a fire suit and a license was deemed too much trouble. Thus the car sat for nearly two years before Matt realized what the next chapter of this Mustang's life would entail.
The idea of dropping in a mod motor hit. It was definitely something new and different, and Matt knew that with a supercharger, the Four-Valve engine could make some good power. Oddly enough, he found someone who was converting a '97 Cobra to Windsor power, so Matt purchased the 4.6 along with the computer and wiring harness. Getting it in the car was the hard part.
Through the grapevine, Matt heard the stock 4.6 engine internals were good to only about 500 hp, so before the motor went in, Sean Hyland Motorsport/Manley 0.020-over pistons and Eagle rods were installed. The pistons were low-compression forgings that dropped the compression ratio to 8.3:1.
"The whole thing was a project for sure," Matt says. "You name it, and I had to fix it." An Anthony Jones Engineering K-member solved one problem, but there were plenty of other obstacles that stood in the way. The Flaming River steering shaft had to be modified to clear the '97 MAC 15⁄8-inch headers, and the BBK H-pipe needed to be cut and modified to con-nect to the incorrect headers.
One of the major hurdles of installing a mod motor is figuring out what to do with the brakes, as the stock power-brake booster gets in the way. Matt solved this by calling Mustang Parts Specialties in Winder, Georgia, for a complete Hydroboost kit.
The fuel system is completely custom, as it converted the low-pressure carbureted system to a return-style, high-pressure setup. The stock fuel rails also needed to be modified to work in this capacity, as the stock fuel system is returnless. A Paxton/Granatelli fuel pump and Mototron 60-lb/hr injectors offer all the fuel a blown 4.6 could ask for.
Since the focus was now on street duty, Matt believed an overdrive five-speed transmission was the way to go. Not expecting a stock tranny to hold up, he went straight for a Tremec 3550 unit and mounted it using a Lakewood '96-up Mustang-specific bellhousing.
The suspension didn't change much. It still employs AVO coilovers with S&W coils up front and Eibach coils in the rear. Southside Machine lift bars are still used. One thing that did change was the rolling stock. Out went the Weld big and littles and on went the American Racing 17x9 front and 17x9.5 rear Torque Thrust IIs wearing 235/45/17 and 275/40/17 rubber, respectively.
With 10 pounds of boost from the Vortech S-Trim supercharger, the 283ci engine put down 503 hp and 410 lb-ft of torque to the wheels using Superchips Custom Tuning software. We invited Matt to one of our track rentals so we could all see just what his filly could do.
His first pass was run on the street radials, and with a 1.86 short time, the Mustang ran 11.90 at 121 mph. Race weight was 3,336 pounds with driver. Matt then brought the Weld wheels out of retirement for the remainder of the runs.
Wearing Mickey Thompson ET Streets, the elapsed time dropped drastically to 11.14 at 124 mph. The early Stang ran consistently with the sticky rubber, with an 11.01, an 11.00 and an 11.04 following the 11.14. Try as he might, Matt couldn't get a 10-second slip, but we won't argue with an 11-flat. The Mustang's trap speed had crept up to nearly 126 mph, too.
Now that the car is a lot more civil than when it had its solid-roller-cammed 373 Windsor, it sees a bit more street duty. Matt put his experience with Mustangs to work recently by opening Performance Evolution in Middletown, Delaware, a full installation and tuning center. "We do everything but paint and rollcages," he says. The evolution of his Mustang continues, however, as plans for an intercooler or some methanol/water injection are in the works.