All projects start with one common theme: the purchase of a car. New or used, the only difference is in how we go about upgrading it. For Ken Cranmer, a Brick, New Jersey, resident, his choice of an '04 GTO was an obvious one. "I bought the car to drive and race," he says, "and because I liked the new body design."
Ken's purpose for this exercise was to build a quick drag car that he could still drive on the street; and he did. The GTO has always been a performer, and Ken's is no exception, ultimately proving its value by running a recent best of 9.77 in the quarter-mile at 141 mph. But, of course, it didn't come from the factory like this. Rather it came with the expertise of Cartek, in Garwood, New Jersey. With little more than a goal in mind, Ken gave Cartek's Dave Busch a ring.
Cartek took good care of Ken's needs. "It started simply with a few bolt-ons--15/8-inch SLP midlength headers, a Vigilante torque converter with a stall speed of 3,800 rpm, and a little bit of tuning," Ken says. "The GTO ran 13.30 at 103 mph, but I was looking to go faster." Next up was a head and cam from Cartek with a Squires Turbo Systems turbocharger set to 8 pounds of boost bringing up the rear--literally. "It ran 10.67 at 135.43 mph, but it still wasn't fast enough," Ken says. When he went back to Cartek, it was mutually decided to build the short-block for increased durability and more power potential.
Since the next step was obviously to strive for the 9's, Dave Busch pulled the engine to be rebuilt. Cracking open the bottom-end--so Ken wouldn't risk doing it literally on the track--Dave honed the cylinders to 3.905 inches (346.84 total cubes) to clean up the walls. After the new rotating assembly was balanced, the factory 3.62-inch stroke crank was reinstalled using Clevite 77 main bearings. Manley forged-steel H-beam rods that were just a smidge over stock length at 6.125 inches came next, using the same brand bearings, and fitted with Diamond forged and dished pistons and rings. To keep the bottom-end cooled and lubed, the stock oil pump was ported before a shimmed pressure relief spring was installed.
A Comp Cams hydraulic roller with 224/230 degrees duration at 0.050, 0.560/0.560 lift with the factory 1.7:1 rocker arms and a 114-degree lobe separation angle is the heart of this potent package. Dave decided to run this cam because it is has more exhaust duration, which helps optimize the turbocharger's power potential.
To maintain the improved breathing, Cartek reinstalled its Stage 2 X heads. Fully ported to flow 302 cfm intake and 220 cfm exhaust, these heads feature stainless steel 2.02 intake and 1.57 Manley exhaust valves, along with reshaped combustion chambers to promote a more efficient burn. Compression checks in at 9.2:1. Strong Comp Cams 921 dual valvesprings ward off valve float, while Manley 5/16-inch pushrods deliver the cam's wishes to the rocker arms.
To further increase airflow, the stock 75mm throttle body was ported, but the factory 75mm MAF was retained.
A set of 83-pound injectors from Siemens were deemed necessary to provide the fuel to match the potential airflow, as was an external fuel pump. The stock regulator was set to 60 psi. Ignition is provided by a completely stock coil-on-plug system and NGK TR7 plugs to light the fire.
When it came to the turbo, Dave decided to keep the preexisting STS rear-mounted system but to alter it to deliver more air. To do so, he replumbed it with 3-inch stainless pipes and stepped up the turbo from the kit's Garret GT67 to a GT76. "The GT67 has a 67mm compressor wheel," Dave says, "while the GT76 has a 76mm compressor wheel. Both share a P-trim exhaust wheel and an AR ratio of 0.81. But, the GT76 is rated to 1,050 flywheel horsepower, while the 67 is only 750."