This redline-charging MK IV Supra has been through more transformations than an aging drag queen. It has been configured for road circuit racing, drifting andstreet use. Jonathan Hsu bought the car new off the showroom floor in 1995 but it wasn't until he started working at Do-Luck USA in Kent, Wash., that the real morphing kicked in.
"We've been using this Supra for circuit races around the Northwest," says Hsu. "Pacific Raceway, Portland International Raceway, Bremerton Raceway and Spokane Raceway Park; it gets around." In 2003, Do-Luck entered the car in the D1 Grand Prix and the company's Japanese arm sent professional D1 driver Kuni Tanakuchi to drive it. Little time to drift-tune the Supra and practice, however, meant the car and the driver were never in sync. It was a challenge but also a great experience.
The D0-Luck team upgraded the motor to a more responsive and higher power setup for its main motorsport pursuit-circuit racing. One of HKS' snewest turbos, the TO4Z ball-bearing turbo, was the first choice, but HKS didn't have a TO4Z kit for the JZA80 Supra at the time.
Fortunately, SP Engineering came to the rescue. HKS had a lot of individual items to piece together a turbo system. These included a stainless-steel turbo manifold, GT-II 60mm wastegate, Type-R intercooler, downpipe and a SSQ blow-off valve. SP fashioned the intercooler piping to connect the dots and the boost was ready to flow.
They didn't just stop there. "Since this motor was destined for circuit races, low-end response and power needed to be there coming out of the corners. So we went with the HKS 3.4-liter stroker kit," says Hsu. "With the stroker kit, low-end agility and power are dramatically increased and there's no need to worry about the sudden turbo spike. The powerband is so smooth it looks almost like a normally aspirated dyno curve."
Turbo crashed the dyno fest as the combination was being tuned. We were able to call-up charts of the final tune and runs before and after the stroker kit to illustrate the benefits of going big on displacement.
With a twin pump setup and 1000cc HKS injectors handling fuel and a HKS Twin Power DLI with Knock Amp energizing the spark, the 2JZ was tuned to 652 whp at 1.7 bar via an HKS F-CON V Pro. The power of the stroker setup is illustrated on charts where we called up 1.2-bar runs before and after the displacement expansion therapy. The peak output of the two runs was similar; the story here is told from the initiation of sampling to 4500 rpm. In this portion of the curve torque jumps 96 lbs-ft at 3500 rpm and 112 at 4000 rpm. Horsepower is bumped 98 ponies at 3500 rpm and 103 at 4100 rpm. With 300 lb-ft of thrust in full effect at 3600 rpm, the Supra should pull through the corners with dominant authority.
The Supra looks the part of boulevard bruiser, proudly wearing a full Do-Luck T-1 Supra aero kit. The kit consists of a front bumper, T-2 side skirts and a rear bumper. The car's demeanor is further enhanced with a Do-Luck 3D carbon rear wing, Do-Luck front blister fenders, rear overfenders and a TRD hood.
Looking beneath the sheetmetal, HKS Hipermax coil-overs deliver the wide adjustability required to generate track grip and street-ride quality. Along with the dampers a myriad of chassis stiffening parts help take the Toyota to the next level on the track. These include Do-Luck power assist bars, a rear cross bar, floor support bar and a rear tower bar.
Other key players like a high-capacity Fluidyne radiator and HKS oil cooler address durability while upgraded Brembo brakes, grippy Toyo Proxes T1-S tires wrapped around Do-Luck Double Six wheels and an HKS twin-plate clutch improve performance.
They say reinvention is a form of evolution; this Supra has seen more reinventions than Godzilla himself. Yet each transformation takes the best attributes of the previous generation and makes them better while evaluating and addressing whatever shortcomings may be hiding in the weeds. Shortcomings are becoming real hard to find at this point.