1994 Toyota Supra Twin Turbo - Electronic Wizardry

Fuel and oxygen make power. SPI addressed these important issues with a Denso Mazda 20B fuel pump, SX regulator and 720cc injectors on the fuel side and HKS GT2835 ball-bearing turbos mounted to a trick HKS manifold on the induction side. The turbos run a 52T compressor wheel and a 10cm2 turbine wheel to provide a hard-hitting combination of spool up and high-end flow. With 35 psi of boost as a ceiling, a HKS Racing wastegate was employed to allow the turbos to spool properly by not opening pre-maturely under the crunch of nearly three dozen pounds of pressure. On the top end the wastegate ensures the speedy ball-bearing turbos will not overboost, which can result in a blown head gasket or worse. Anyone who has suffered the effects of slow-motion spooling or boost creep can appreciate the job a good wastegate does. Once the exhaust gas has done its duty, an APEXi GT-series exhaust system escorts the spent fumes out of the picture.

Electronic wizardry is again on display when it comes to the tuning of the 2JZ-GTE. Hubie says it's alphabet soup-VPC, ITC, AFC, AVC-R. An APEXi AVC-R Digital boost controller works in tandem with the aforementioned HKS Racing wastegate to limit the boost. The Supra retains its stock ECU but relies on hardcore off-the-shelf tuning instruments. First on the list is the Supra mainstay, HKS Vein Pressure Converter (VPC), which eliminates the restrictive factory air meter (see May 2001 Turbo). Next is an APEXi Super ITC ignition timing controller that allows tuning of the crank angle signal 15 percent plus or minus stock via five rpm knobs on the unit. The ITC works hand in hand with an APEXi Super AFC Digital fuel tuning computer that flexes eight rpm points of tune and a plus or minus 50 percent tuning window.

We have been eyeing this car for a long time but Hubie wanted to make power before letting us at it. The wait paid dividends as Hubie knocked our socks off. With a stock ECU and some piggyback computers the Supra was tuned to 624.5 hp at its street boost of 22 psi on 93-octane pump gas. With the bar raised to 24 psi, the Toyota belted out 649.1 hp. Boost was pushed to 28 psi and Hubie added five gallons of 110-octane to the tank, which he figured had seven gallons of 93 still in it. The result was a wicked 721.1 hp. Hubie calls this figure conservative, as he is seriously considering sticking to the 35 psi game plan. Wow! A Kaaz limited-slip differential and SPI clutch have the unenviable task of putting the power down to the ground through the Toyota's six-speed manual gearbox.