These custom valve covers and coil brackets from Smitty's Speed Shop spice up the looks under the hood. The intake manifold and elbow provide the ported LS6 heads with an unimpeded influx of forced air.
The valve events are controlled by a Flow Tech roller camshaft with 230/228-degrees duration and 0.612/0.600-inch lift on a 115 LSA. Rick conscripted Jeremy Formato's Fasterproms in Tampa to port and polish the stock No. 243 LS6 heads. These heads also benefit from a set of 1.7-ratio Scorpion aluminum roller rockers, dual valvesprings, and ARP head studs.
Next, Tom installed an APS Twin Turbo kit on the Goat. According to APS, this will provide a more balanced application of power and reductions in the back pressure, cylinder pressure and temperature imbalances from cylinder bank to cylinder bank than a single turbo on a V-8 configuration. APS also promises better low-end and mid-range boost response using its twin moderately-sized turbos instead of a single large turbo. "These turbos build boost almost instantaneously!" exclaims Tom.
Inside, you're met with a welcoming environment. Plush, comfortable seats are covered in high-quality red leather and stitched with the GTO name. The gauge cluster matches the seats, has a red face, and tells the driver a glut of information.
APS says its turbos "are based upon custom Mitsubishi gasoline-spec [units] with an Inconel 713C turbine wheel, liquid-cooled bearing housing (50 pounds per minute mass airflow at 18 psi), APS single-entry 0.84 A/R turbine housing with external wastegate port/provision and APS-designed and manufactured 0.65 A/R compressor housing."
They are lubed and cooled by oil, as is common practice, but heat is further dissipated by engine coolant via passages around the bearings. Reducing bearing temperatures eliminates the coking and lacquering issues suffered by turbos cooled with oil only. APS High Volume Twin Vent blow-off valves are employed as well.
This kit places the turbos nearly out of sight, making for a particularly unassuming engine bay appearance when a factory intake manifold is installed. That isn't the case with Rick's Pontiac, though. To complement the increased airflow capability, Tom installed an Edelbrock Victor Jr. intake manifold with a custom intake elbow. Made by Smitty's Speed Shop in Sarasota, Florida, this elbow allowed Tom to reuse the factory fly-by-wire 90mm throttle body. The mass air meter was removed and the system was changed over to speed density. This makes it easier to tune the car on forced induction, according to Jeremy. Smitty's also crafted a set of coil pack relocation brackets and valve covers, giving this GTO an ultra-clean look under the hood.
Because the late-model GTO strayed away from the traditional look of a musclecar, many felt this M3 competitor lost the roots of its heritage. But it certainly lived up to the performance potential-Rick piloted his GTO to a 12.8 in stock trim. That's all muscle.
The factory fuel system wasn't adequate to feed the beast and meet the increased fuel demand. APS's kit includes 60-pound injectors, and Tom kicked up the fuel flow further by replacing the factory fuel pump with an Aeromotive A-1000. He also installed an Aeromotive boost-referenced regulator for precise pressure control. This extreme combination provides Rick with the option of increasing the power levels down the road.
Once the hood is closed, there's little inkling to the power that lurks underneath. Rick wanted to increase efficiency and retain this sleeper look so he used APS's intercooler since the company paints it flat black for a super-stealthy feel. The goal of the APS unit is to "achieve the maximum-charge air temperature drop with the lowest possible pressure drop across the entire intercooler system."
But the increased cooling efficiency didn't end there. A Devil's Own progressive alcohol kit was used to lower the intake charge temperature even further and allow for more boost on pump gas.
Exhaust exhales into the APS iron manifolds where the pressure is routed to each turbo. Excess pressure flows through custom 3-inch pipes and high-flow catalytic converters. Rick's GTO utilizes a set of Magnaflow mufflers that effectively quiet the roar of the beast, yet flow very well at high power levels. This gives the GTO a tame sound-until he rolls into the throttle.