Michael Galimi
May 29, 2014

The installation is fairly straight forward, with the head unit bolting into a dedicated bracket system that is hung off the driver's side of the engine. The discharge piping is run down and into the front-mounted intercooler, the air exits the cooler, and then ultimately enters the throttle body thanks the massive aluminum pipes included in the system.

Procharger prescribes '03-'04 Cobra fuel injectors for its kit, which are rated at 39-lb/hr with 39 psi of fuel pressure. A second fuel pump and installation kit is included to help supply the hungry injectors with dead-dinosaur juice.

A major modification to the kit was the custom MAF sensor location. Krazy House Custom specifically installed the factory MAF sensor in one of the discharge pipes after the intercooler for smoother flow and a better MAF signal. Carrabba then sent the pipe—with the relocated MAF sensor—to PMAS for flow testing. The flow/voltage curve of MAF sensor and housing is vital for the ECU calibration.

Essentially the MAF sensor reads the mass of air that is flowing past it; the reading is measured in volts. The ECU is programmed to assign a certain airflow value to the voltage reading to determine how much fuel is needed to feed the engine.

PMAS flowed the supercharger pipe with the MAF sensor installed and created a transfer function. That information is used to add values in the MAF transfer function portion of the SCT software. Tuners will spend countless hours using a trial-and-error method to get the transfer function correct, whereas Carrabba has the exact flow curve and can skip that tedious process. He can program the ECU with an accurate voltage/airflow value, making the engine run smoother and cut down considerable tuning time.

LaRocca's near-stock GT produced a paltry 291 rwhp and 308 lb-ft of torque at the wheels sans blower. After the Procharger was installed and Carrabbi fiddled with the calibration, the Three-Valve made an impressive 405 rwhp and 384 lb-ft of torque on 7.5 psi. Those results were accomplished with a very conservative 15 degrees of ignition timing and an 11.2:1 air/fuel ratio.

“We wanted to start Jim with a mild tune so he can learn to drive the car,” Carrabba said. “Once he gets more time behind the wheel, then we can turn up the boost and put a little more timing in it.”

As the nasty New Jersey winter is coming to a close, the LaRocca family is itching to get on track so they can get the Three-Valve singing with the 7.5 psi of boost flowing.


10. A massive air-to-air intercooler is located in the front bumper area and is mounted using three sets of brackets.

11. Once the intercooler was bolted into place, it was time to add the charge piping. A bypass valve attaches to the pipe in the lower corner on the driver’s side, just outside of the engine compartment. A bypass valve relieves pressure in the system when the throttle blades close. This is done so air doesn’t “back up” into the centrifugal supercharger, which causes turbulence that’s capable of breaking the head unit.

12. LaRocca adjusts the charge piping as he works his way from the supercharger to the intercooler, out of the ’cooler, and into the throttle body. Rubber couplers and clamps are used to join the different sections of piping together.

13. Here is the custom MAF sensor location that Krazy Horse Customs built for this application. PMAS flowed the pipe and MAF sensor to create a flow/voltage chart for the MAF transfer functions in the SCT tuning. The specific placement of the MAF sensor produces a clean signal and reduces the time it will take for Brandon Carrabba of Krazy House Customs to tune.

14. The relocated MAF sensor requires extension of the factory harness. The Krazy House Custom guys stressed that you have to use quality wire and solder the wires.

15. The charge piping fits in perfectly, but the tight confines of the engine compartment required Procharger to include a new overflow tank, which now mounts on top of the radiator.

16. A Shelby GT500 pump is included in the kit, and Procharger supplies the required materials, such as a clamp, a fuel pump sock, and fuel line in order to add the second fuel pump. LaRocca pulled out the fuel pump by removing the back seat and accessing the drop-in fuel-pump setup.

17. Of course, the elder LaRocca was compelled to jump in and check over his son’s work to ensure it was all systems go. Once he gave the green light, it was game on for the Mustang GT to spin the chassis dyno rollers at Krazy House Customs.

18. The results of just 7.5 psi of boost—405 rwhp and 384 lb-ft of torque. Krazy House Customs utilizes a Mustang Dyno, which generally reads 10-15 percent lower than the more traditional DynoJet chassis dyno. Also included on this chart is the car’s best run in naturally aspirated trim, 291 rwhp and 308 lb-ft of torque.