With 500 horsepower from its supercharged V-8 engine, you’ll find few who would argue the Shelby GT 500 is a slouch. Still, what the factory delivers is merely the starting point for many enthusiasts and if, say, FoMoCo delivered a 950-horse Mustang, there would a full-court press underway in the aftermarket to reach the 1,000-horsepower level.
It’s for those who can’t leave well enough alone that businesses such as Paul’s High Performance thrive. And no sooner did the GT 500 hit the ground than customers’ cars hit Paul Svinicki’s chassis dyno. Svinicki has developed a homegrown performance package for the GT 500 that pumps up rear-wheel output from the stock 415-hp level to more than 550 horsepower.
The power increase comes via the following:
• Ported and port-matched supercharger case, inlet elbow and throttle body
• Cold-air induction system
• Cat-back exhaust system
• Custom calibration
Our black GT 500 project vehicle produced 412 rear-wheel horsepower in stock trim, along with 399 lb.-ft. of torque. After the go-faster parts were added, rear-wheel output jumped to 556 hp and 524 tugboat-like lb.-ft.
The engine mods comprise Paul’s “Stage III” GT 500 setup and the one on our project car included a pulley change. Additionally, the GT 500 package includes new shifter bushings that firm up the shift action and rear lowering springs, which give the car a more balanced stance. All the parts, labor and dyno tuning add up to roughly $5,000 worth of work at Paul’s Jackson, Mich., shop. That’s less than the cost and installation of a supercharger for a naturally aspirated engine yet it delivers about the same power boost – along with an improved shifter feel, exhaust and lowering springs. In our book, that’s a value.
For a little extra out of your checkbook (well, “a little” is a relative term – ask your wife, first), a Whipple supercharger will replace the factory Eaton unit and output increases exponentially. We recently followed along with the installation of the Stage III parts, the exhaust, rear springs and shifter and were impressed with the quality of Paul’s custom components and relative ease at which they were installed.
In a reversal of the “Terminator” cars, where supercharger removal/replacement is a bear and a shifter swap is a snap, the GT 500 cars feature killer shifter swaps while the blower swap is a relative cinch. The compressor simply lifts straight off the manifold.
In addition to the increased performance, Paul Svinicki reports another bonus of the package: Lower exhaust temperature.
“The exhaust temps drop by up to 30 degrees over stock,” he says. “It’s a dramatic difference.”
Paul’s also sells the individual components of the GT 500 package separately and maintains a stock of ported/polished blowers that can be had on an exchange basis (with the requisite core charge). If you’re within driving range of Jackson, Mich., however, it’s worth a couple of days to take your car to the shop for a personal installation and tune. This should be particularly considered if you want the blower pulley changed – it’s not an operation for the weak of heart or inexperienced wrench turner.
We’re constantly amazed at the relative ease at which so much more horsepower seems to flow readily out of an uncorked GT 500 engine. And Paul’s High Performance proves that it doesn’t take an unlimited credit balance or Unobtanium parts to produce unbelievable results.
Paul’s High Performance