The British car industry has a lot to answer for. Example: the '95 Rover 220 Turbo Coupe. This was built on a Honda platform-the Concerto, as Honda had a stake in Rover at the time-it was front-wheel drive and had a 200hp engine. The Rover version deployed MacPherson struts up front-the JDM Concerto used double wishbones. By now, the words torque steer should be springing to mind. Despite a Torsen torque-sensing differential, the 220 Turbo was not kind to it's front tires.
Not that Cenk Ocakoglu was too bothered. This was his first ride, wheelspinning through the streets of Istanbul, in his native Turkey. He even raced it. And just as some people don't know they're alcoholics until their first drink, Cenk became addicted to boost. He tuned the Rover to produce 230 whp, obtained a mechanical engineering degree, and set up a parts business.
Coming to America in 2000 to obtain his MBA in Finance, Cenk acquired this '94 Toyota Supra Twin Turbo on the JZA80 chassis. He had already done his homework and found the Supra to be the best platform for tuning after the Nissan Skyline GT-R. And how many Skylines are there in the States? Cenk is now a performance specialist with Garage GT, calls San Diego, Calif., his home, and is 31 years old. Young enough to be influenced by Gran Turismo, but old enough to know the virtue of patience; he's grown out of the need for instant gratification.
Which is just as well, because this Mark IV Supra build is still considered to be an ongoing project. At first, Cenk pushed the stock turbos to produce their maximum output. Then, he tried something similar with the stock 2JZ-GTE engine and a big single turbo. Nice try, but no pungent Turkish cigarette. The kind of stuff Cenk was jonesing for needed a built motor and some serious investment in time, money, and expertise, plus that most precious of human commodities: patience.
The iron-block bottom end of this 3.0L straight-six is renowned for its strength and ability to cope with the stresses that come from high boost levels. So, short block mods are Crower billet connecting rods pushing Wiseco 86.5mm pistons-running with a compression ratio of 8.5:1. The pistons have been PolyDyne coated, a process that reduces friction and heat loss through the piston. Both traits contribute to more horsepower at the flywheel.
Above the level of the HKS 1.6mm head gasket is where most of the engine work has been concentrated. HKS 264 intake and exhaust cams and adjustable cam gears join Ferrea valves, titanium retainers and valvesprings inside the Head Games prepped aluminum head. To be on the safe side, with so much power churning around, the factory head and main studs have been upgraded to ARP items.
At the heart of the forced induction system is a single Garrett GT4274 turbocharger, set at 53-trim and with a 0.81 A/R ratio: "A fairly small unit when compared to most high-power Supras," said Cenk. Cleansed by a K&N filter and 4-inch tubing, the turbo directs boost into a Hypertune 90mm throttle body and intake manifold. An AEM plug-and-play engine management system orchestrates the GM boost control solenoid (yeah, General Motors; who'd have thought? "It's a three-port and works great with the AEM EMS boost control map," said Cenk), HKS turbo timer and Twin Power DLI ignition amplifier-claimed to produce crisper throttle response and a smoother powerband.
Gasoline comes up from a Fuel Safe aluminum fuel cell, fed by an Aeromotive external fuel pump and fuel pressure regulator into a Hypertune fuel rail via -10 stainless steel lines, before being shot into the combustion chamber by Precision 1,000cc injectors. That's when NGK iridium spark plugs ignite these two elements, releasing their combined energy.