Steve Baur
Former Editor, Modified Mustangs & Fords
January 22, 2007

For starters, Jimmy made sure that our GT maintained a safe air/fuel ratio throughout the power range. Taking into account the Mustang's high-mileage and many heat cycles throughout the years, Jimmy kept the a/f ratio to 11.5:1. He could have easily squeezed another 10-15 hp out of it, but we wanted to be on the safe side, and our horsepower gain was more than enough to put smiles on our faces. Idle quality is another thing that can be adjusted with the chip. Many factors go into tuning this equation. Things like how the throttle position is set and the type of mass air meter and injectors used are all orchestrated by the computer. One more important thing that can be adjusted with the computer chip is boost retard. We were not aware of this when we ordered the Crane timing control module, but it can be compensated for in the computer tune. With the age of the engine being the main factor, LaRocca opted to pull out four degrees of timing to ensure safe operation.

Prior to tuning, the base ignition timing was set back to 10 degrees. A few pulls were made to get the idle and air/fuel ratio set, and then LaRocca, with help from Andrew Barrale and Jimmy Chahalis, went for the power. How much did we get? Well, remember that the stock figures were 202 hp and 275 lbs-ft of torque. With the ProCharger pumping 10 psi of boost we made 333.4 hp and a stump-pulling 389.7 lb-ft of torque at the rear wheels. Now that's some LS1-smoking power in our little 3,200-pound GT. Given a drivetrain loss of 15 percent, we estimate flywheel horsepower to be around 390, and torque to be about 448 lbs-ft.