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Editor's note: This is part of a series at KSL.com featuring some of Utah's coolest cars. If you own a customized vehicle — from sports cars to semitrucks — email fjolley@ksl.com with a photo of the vehicle and a brief description for consideration.ROY—Ever since the Ford Mustang was first sold in the 1960s, it can be seen as a typical American muscle car. However, Jeff Streeper’s 2011 GT500 is not a typical Ford Mustang.
He first purchased the car in 2015 with the desire to have a fun, fast and worry-free ride, and the GT500 made his dream into a reality. With less than two months of ownership, he and his wife took the car on a 2,000-mile road trip from Oregon to San Francisco and the car performed perfectly.
The next goal on Streeper’s list was to have the car dyno’d (measure the output of an engine with a dynamometer) at Premier Performance to see what kind of power the car was putting out in its unmodified state, and it didn’t disappoint. With a rear-wheel horsepower number of 496 flashing up on the screen of the dynamometer, he caught the itch to start modifying his ride.
The first round of modifications came in the form of a smaller supercharger pulley (to crank up the pressure put out of the factory supercharger), an aftermarket intake system (to help feed cooler air into the supercharger), a custom tune to get the most power out of his modifications, and an HPTuners nGauge for displaying and logging the car's newfound power.
While these new mods didn’t generate a large horsepower gain, Streeper decided to compete in a half-mile racing event in Arizona.
“That racing event was by far the most fun I've ever had in a car,” Streeper said. “I highly recommend it to anybody.”
His GT500 hit a speed of 147.63 mph in the half-mile and it performed as flawlessly as it always had, even though it was dealing with the extra heat of Arizona.
The car had done everything Streeper had asked of it, but like a persistent itch, the aspiration for greater horsepower got the best of him.
The next round of modifications would drastically change the car into a completely different vehicle. Streeper started the next modifications with a 2.3-liter Gen 2R supercharger swap from the factory blower, followed by a larger heat exchanger to help cool the air of the bigger supercharger that now resided under the hood.
Next, a set of 56 pound-an-hour fuel injectors were installed to help meet the needs of the power output of the new setup. A set of 15-inch wheels and drag radials, a 67 mm throttle body and a custom tune would put the finishing touches on the car.
With a final horsepower number of 625 at the tire and 633 pound to feet of torque to match, the car was ready to race again.
It went on to run the quarter-mile at the Rocky Mountain Raceway in 11.36 seconds at a speed of 123 miles per hour, which at the high elevation of the track, is substantially faster than a factory GT500.
“I wanted a fast, comfortable, reliable car and that's exactly what it has given me,” Streeper said. “It's no-show car because it gets used and enjoyed. In my mind, there's no point in having a car that just sits in the garage collecting dust.”
