He fabricated equal-length headers from 321 stainless steel. Up-pipes, downpipes, and wastegate dump tubes were formed from 304 stainless. Ceramic coating on all tubing and the wastegates protect these parts from extreme heat. The GT30R ball-bearing turbochargers feature a custom, four-bolt exhaust housing.
“I crammed the largest Garrett intercooler cores I could fit into the areas where the stock mufflers used to live,” he explains. He fabricated custom end tanks for these. Tial 50-mm blow-off valves were placed just before the intake. “After the intercoolers, I worked on the top end. I was making this huge intake plenum fed by one throttle-body. But midway through that, I ended up getting TWM individual throttle bodies, so I built plenums above those.” He modified the TWMs so he could retain air-conditioning — important for Houston summers — and installed dual Golden Eagle vacuum manifolds.
According to Princeton, “modifying the TWMs to accept a plenum on top and getting all that stuff aligned” was the biggest challenge of the project. This is where the throttle linkage issue resides. “The way (the pulley) transitions with the linkages on the TWMs, it starts off facing backward.” That played havoc with the linkage, and Princeton isn’t satisfied with the current setup, either. “It’s kind of annoying, and I haven’t gotten around to working on it,” he admits.
He upgraded the Bosch fuel pump and installed Pro-Lite fuel lines, Earl’s Ano Tuff fittings, and a Precision fuel filter. Next, he fabricated billet aluminum fuel rails to feed the six Precision 1000-cc injectors. An Aeromotive fuel-pressure regulator and a Marshall fuel-pressure gauge round out the fuel system modifications.
As intake work continued, a Formula SAE team offered a Motec M48 ECU for a price that was too good to pass up. Princeton soon worked it into the equation, as well, calling on Sam Shalala at Protechnik to help sort through the initial setup.
Early on, Princeton recognized the need for effective heat management in the crowded engine compartment, so he engineered several elegant solutions. The first focused on the intercoolers. “Because I decided not to cut holes in the fenders to push air through the intercoolers, I designed a custom ducting system fed by the engine cooling fan,” he says. As a result, higher engine speeds equal more air. Also, he customized the rear bumper to vent hot air.
Princeton fashioned a fluid cooling system that pumps coolant through the twin turbos. A custom aluminum coolant tank, a Meziere water pump, and a Setrab cooling core reside in the rear-seat area. The system pumps Evans waterless coolant, which he says “has an extremely high boiling point, so I don’t have to worry about cavitation or boil-over in the closed system.”