Pete Epple Technical Editor
October 1, 2009
Wiring the new pump is made easy thanks to the wiring kit and relay from Meziere.

With our '10 Mustang back at 160 degrees, Jones made another pull on the Dynojet. The addition of the electric water pump freed up 3 rwhp, bringing our total number to 289. "I was extremely surprised to see such a minimal gain from the Meziere pump," explains Jones. "We install these pumps all the time, and this is the first time we haven't seen at least an 11 rwhp gain." Even without the usual gain, Meziere's electric water pump is still a must for anyone who runs open-track days, autocrosses, or drag races. The added cooling benefits of constant water flow make this simple bolt-on invaluable the first time you need to keep your engine cool on a hot day.

As Ford stepped up power with the redesigned '10 Mustang, the GT now comes stock with a cold-air intake from the factory. This coupled with a few calibration changes has boosted the factory output from 305 hp to 315 hp. With this in mind, Jones and Frith decided to see what improvements could be made over the stock airbox. After a quick trip to the parts room, Jones emerged with a BBR GT500 throttle body and adapter plate, and quickly replaced the stock piece.

In an effort to improve the flow into the intake, Jones installed a BBR GT500 throttle body and adapter plate. The kit comes complete and adds a twin 60mm throttle body to replace the stock twin-57mm unit.

After a call to JLT Performance, Jay Tucker informed us that its '10 cold-air intakes were still in development. By the time this issue hits newsstands, JLT will have released an all-new 101 mm cold-air kit for the 2010 Mustang GT. This left us with two options-either leave the stock airbox or customize one of JLT's '09 kits looking for whatever gains we could find. Not ones to leave well enough alone, we unboxed the '09 kit and made a few changes to accommodate the engine bay of the '10. The '09 JLT cold-air kit replaces the airbox and intake tube and provides an 89mm MAF housing replacing the stock 86mm unit. The kit reuses the stock MAF sensor, which slips into the larger housing.

After a quick change in the tune, Jones was ready to make another pull on the dyno. Our test confirmed the efficiency of the stock cold-air setup as we only saw gains slightly under 4 rwhp and 2 lb-ft of torque, bringing our totals to 292 and 309. A second call to JLT reaffirmed that the '09 kit would not produce the gains seen on previous Three-Valves, and the new 101mm set would give us the numbers we wanted.

Although the '10 cold-air intake from JLT Performance is still under development, we decided to retrofit an older version to see if there would be any improvements over stock. The 89mm MAF housing from the '09 kit was installed and showed gains of about 4 rwhp. According to JLT, gains should be much higher with the 101mm kit for the '10 Mustang, which should be available by the time you read this.

To finish off our mods on the topside of Frith's '10, Steeda sent us a set of its charge motion delete plugs. These billet-aluminum pieces replace the butterflies in the intake runners and allow for unrestricted airflow into the cylinder heads. Once the intake manifold is removed, the linkage assembly is removed from the backside of the intak, along with the butterflies. The guide clips are reinstalled on the new plugs, which slip right into the bottom side of the manifold. This requires changes in the tune and Jones was quick to reflash the ECM.

With another quick pull of the dyno, our 2010 was now pumping out 296 rwhp and 310 lb-ft of torque. Although we showed a slight gain across most of the rpm range, the full 4-rwhp gain was seen at the top of the rpm range.

After finishing the mods under the hood, Jones and Frith put the car in the air and turned their attention to the exhaust. Jones pulled a Magnaflo x-style midpipe off the shelf, and American Muscle sent us a Roush high-performance axle-back exhaust system. Both pieces are a direct replacement for the factory parts and fit perfectly.

With the exhaust off the car, it was the perfect time to upgrade the shifter. A call to Roush Performance scored us one of its '10 short-throw shifter assemblies, along with a billet shift handle, white knob, and new leather boot. The transmission was lowered and Frith quickly swapped shifters before installing the new exhaust pieces. Once the underside of the Stang was buttoned up and the tailpipes were aligned, Jones rowed through the gears, spinning the rollers to 309 rwhp and 325 lb-ft of torque.