Muscle Mustangs & Fast FordsHow To Engine
'07 GT500 - Bolt-On Nines
It's so easy, it should be illegal.
Ever since the '03 SVT Cobra appeared, the performance world has never been the same. All it takes is bolting on a larger supercharger (or turbocharger) and letting it rip. OK, technically it's a little more than just that, but the point is that Ford has supplied the '03-'04 Cobra with stout engines that are quite durable.
The Shelby GT500 comes from the same bloodline, namely a ridiculously tough engine package. Case in point is Billy White's '07 Shelby GT500 that recently participated in MM&FF's Shelby Shootout. We find it amazing that the Shelby ran 9.92 at 142.50 mph with nothing more than what most Shelby owners add to their potent S197 specialty cars.
We're writing this story partly because we goofed and ran the wrong photo in the Shelby Shootout article, and because we neglected to mention some important people involved with this car.
During our discussions with Justin Burcham of JPC Racing, we discovered that this Shelby is an extraordinary vehicle, one that is not as modified as you would think for being a certified nine-second machine. Take a showroom stock Shelby GT500, add the parts listed below, then go out and run in the nines. It's that simple--provided you have a wallet big enough to accomplish the task.
It all began innocently enough when Billy brought his spanking-new Shelby GT500 to JPC Racing for a few modifications here and there. Then it got real serious with a larger blower and everything to go along with it. The most obvious add-on is the enormous Whipple twin-screw blower. It displaces a rather impressive 3.4 liters and is capable of nearly 1,000 hp in the proper application. Justin has this one spinning hard enough to pressurize the Four-Valve engine to 21 psi. Expelling the spent gases is the job of JBA long-tube headers, a 3-inch cross-pipe, and a Bassani 3-inch after-cat exhaust system and mufflers. Feeding the thirsty engine are a dual Boost-A-Pump system and JPC-modified Shelby fuel injectors. An Afco heat exchanger chills the water that is stored in a Moroso aftercooler reservoir. Justin said they stuff the reservoir with ice to maximize the chill factor. Lighting off the mixture of VP C16 and Whipple-stuffed air is the job of the factory ignition system aided by a set of Brisk spark plugs.
As with all of the Mustangs since 1996, reflashing the computer with a modified tune is very important to longevity and performance. The Shelby was put on the rollers at JPC Racing where it was not only tuned for wide-open throttle, but also street driving manners. Using DiabloSport software (and a DiabloSport Predator to upload the tune), Justin conspired with one of the company's head computer tech guys, Kevin MacDonald, to get this Shelby's computer just right. The dyno results are an outstanding 870 hp at the rear wheels on VP C16 fuel--we'll call this the track tune-up. On the street, Billy enjoys 760 hp at the rear wheels while running 93-octane pump gas and knocking down 18 mpg on the highway. Remember, this is a 5.4L engine that hasn't even been touched, save for the aforementioned bolt-on parts.
There's more to the puzzle to get a Shelby to run nines, and that has to do with the rest of the car. On the outside, a Cervini's cowl hood covers the supercharged engine. One difficulty with utilizing such a physically large blower like the 3.4L Whipple, is the stock hood doesn't close. Some shops use spacers under the K-member to drop the engine a bit, but Justin just went with a cowl-induction hood. It's a classic and distinct look on this Shelby. Other visual add-on/performance enhancement included the addition of a set of Bogart drag wheels wrapped in Mickey Thompson rubber. The stock Brembo brakes up front had to be replaced with GT brakes in order for the 15-inch Bogarts to fit.
Helping the M/T 28x10.5-inch tires grip is the job of a Metco rear suspension system, set up to JPC Racing specs. It consists of billet lower arms coupled with an adjustable upper control arm. A set of relocation brackets and sturdier Panhard bar were also added. The drivetrain was modified with the addition of a Pro-5.0 shifter, a JPC one-piece driveshaft, a Detroit Locker True-Trac, and a set of 3.90:1 gears. The stock clutch holds its own against the onslaught of all of the ponies and torque from the blower engine.
Those modifications add up to an amazing 9.92 at 142.50 mph with a 1.51 60-foot time. Justin handled the driving chores on that run--not bad for a car that checks in at a portly 3,910 pounds.
Billy would like to say thanks to his wife, Penny. Without her support, he wouldn't have such a wild Shelby GT500 that runs nines.
Justin would like to thank DiabloSport, Whipple, and Cervini's for stepping up and helping out in the 11th hour to get this car ready for the Shootout.