Supra Performer
Text by Robert Choo
Photos by Henry Z DeKuyper

…Many of you might remember our Supra Stars issue of Turbo (February, 2000), where, in tribute to one of the best import super cars available on the plan- et, we unleashed a fury of Supras for your consumption. The issue revolved around Craig Paisley's Supra Drag Monster which graced the cover but a closer look inside highlighted the fact that most of the vehicles featured in the issue were found at the Supras Invade Las Vegas III held on September 17-19, 1999. Christian Rado's street- driven, 10-second strip charmer; Brice Danna's wild, 674 hp, red rocket and Ben Treynor's Supra sleeper were all shot at the event. However, there has been one car that has eluded our grasp - until now.

We first saw Kenneth Henderson's meticulously constructed black twin- turbo Supra in the Luxor parking lot. The Bomex front spoiler, Stillen side skirts as well as the 18-inch, three-piece Manaray wheels, the 14-inch cross-drilled Brembo rotors and four-piston calipers at the corners, were all reasons enough to have the Supra set up for a date with the camera.

Although the body has been sculpted with stunning success, we were surprised to hear that the real work was performed under the hood. Kenneth first started modifying his twin-turbo Supra shortly after purchasing the vehicle. With simple buttons and a pair of tweaked factory turbos, the car was able to pound out 418.3 hp at the wheels on pump gas. In late 1997, Kenneth decided to shift the Supra into high gear and enlisted the help of Alex Shen and Jeff Kung of SP Engineering in City of Industry, Calif. The three brainstormed and drew out a battle plan for the Toyota.

At the time, the easiest way to make more power was to remove the factory sequential turbo set-up and install a large single-turbo system. Although this would meet their horsepower expectations, the power output would only be at the top-end. Since Kenneth wanted a daily driver, the single-turbo approach would greatly increase turbo lag and dilute the low-end grunt needed for around-town driving. To resolve the turbo lag issue and increase low-end power, a twin-turbo set-up was decided upon. Unfortunately, at the time, HKS' bolt-on twin turbo upgrade was not available on the market and GReddy's upgraded system for the 2JZ-GTE powerplant was a single-turbo based unit. The solution was to develop a prototype GReddy-based twin-turbo upgrade. To this day, it is the only one of its type.

Take a peek under the hood of Kenneth's Supra and you can easily tell this was no one-day job. Top Secret a major Japanese-market tuning firm, was enlist- ed to fabricate a tubular, equal-Iength, stainless-steel exhaust manifold based upon SP Engineering specifications for U.S. spec Supras. Advanced Design Fabrication (ADF) of Whittier, Calif. Spent countless hours fabricating the entire system's intake, exhaust and intercooler plumbing with multiple heat shields to prevent heat saturation. SP Engineering then mated Top Secret's stainless-steel exhaust manifold to twin GReddy TD06L2 20G-8cm2 turbochargers. A single GReddy Type-C wastegate, with enough CFM to sup- port 1,000 hp at the crank, was called upon to keep the Mitsubishi turbos in check. ADF was also contracted to fabricate the stainless-steel downpipes, super induction air box and secondary fuel rail.

While running the stock upgraded turbochargers, Henderson had Advanced Automotive of Redlands, Calif. remove the head and intake manifold, sending both to ExtrudeHone to help increase the flow to and from the combustion chambers. Advanced Automotive then performed a multi-angle valve job and resurfaced the head to ensure a tight seal. Although the bottom-end can easily take the abuse of 650-plus wheel hp, SP took no chances and replaced the factory slugs with .020 over 8.5:1 compression JE forged units with Total Seal rings. Sandwiching the head and block together is a set of ARP head studs, while an HKS 1.6mm stopper metal head gasket is in charge of containing boost. Sitting on top is a pair of 264 HKS bumpsticks with JUN adjustable cam gears to fine-tune valvetrain events.

Alex, Jeff and Jason Reinholdt, SP's chief engineer, had their hands full, as they were also responsible for figuring out the engine management system for the 2JZ. Since drivability was a main concern, SP decided to work around the factory ECU and added piggyback electronics to fuel the Toyota at higher boost levels. The factory ECU received some massaging from Shawn Wang of SP, while an HKS V PC was chosen to replace of the restrictive factory airflow meter. Along with replacing the factory airflow meter with the V PC unit, the V PC also converts the metering system to speed density for easier tune-ability. To support 650-plus hp, a set of new 720cc HKS injectors and billet high-flow fuel rail replaced the factory pieces. Controlling the six additional RC Engineering 310i:c injectors is a GReddy Rebic III and Simulator. The beauty of the Rebic III and Simulator is that the system is not activated under light loads, so drivability is not affect- ed, but once the hammer is dropped, the injectors come into full swing for maxi- 1lum horsepower. To keep up with the demand of the 12 injectors, two Supra turbo pumps were called upon to supply he necessary fuel needed to maintain proper air/fuel ratios. An HKS Twin Power ignition amplifier was added to ensure the lightly compressed mixture gets ignited in he combustion chamber.

With more than 650 hp on tap at the pedal, transferring thrust to the extra sticky Bridgestone S-02 285 rubbers out back is not an easy ~ask. A triple-disc OS Giken clutch was called upon for the job. Unlike most clutches which only use one disc, the OS Giken unit utilizes three discs for neck-snapping shifts. Although this light not be the most ideal clutch for the street, it was the only one Kenneth trusted to accomplish the job. Connected to the output shaft of the transmission is a carbon fiber Advanced Composite Products and Technology (ACPT) driveshaft. The carbon fiber driveshaft reduces the weight of the rotating mass without affecting the strength of the driveline.

As we mentioned earlier, from the out- side, the Supra means business. Located at each of the four corners are 14-inch Brembo rotors and four piston calipers from Cooltech/AEM, which easily stop the Toyota from triple-digit speeds in a matter of seconds. Providing the lowered stance are Eibach Sport lowering springs paired with Bilstein shocks. A Cusco front upper strut bearing plate (pillow-ball) also enhances the accuracy of the suspension geometry, facilitating increased turn-in and helps anchor the front-end. A GAB strut tower brace up front and Cusco car- bon fiber strut tower brace out back further tighten up the already-rigid Supra chassis. No super car would be complete without wheels; Kenneth opted to go with 18-inch Manaray MS-6 forged aluminum wrapped with Bridgestone S-02 Potenza Pole Position rubber providing the footprint.

Kenneth has waited nearly two years to complete his ultimate daily driver and, from talking to him, he believes it was time well spent. How many people can say they own a 650-wheel-hp daily driver? He speaks quite highly of the vehicle and you can clearly see why. Wouldn't you be proud if this was your daily driver?

Text and photos courtesy of Turbo Magazine