I well remember my first experience with an HKS-tuned car. It was a 1998 Toyota Supra, the last of the breed, built as a showcase of the Supra's latent potential as a very tunable super car. All HKS did was change out the suspension, wheels and tires and make improvements to the engine's air-moving capabilities (airflow meter, exhaust, intercooler and turbo upgrades). The result, if I remember correctly, was an exercise in sheer terror. I got to take a hot lap in the car with one of my colleagues, and I'm sure there are still fragments of my fingernails embedded somewhere in the car's leather and vinyl cockpit.
HKS has been turning out impressive project cars here in the United States for nearly 15 years, since the American branch of the Japanese aftermarket firm first opened its doors in 1986. Raw material for these projects has ranged from your average, everyday domestic market offerings like Civics or the aforementioned Supra to strictly Japanese-spec unobtainables like the Nissan Skyline GT-R. In recent years, HKS has expanded its product lines to accommodate American cars, European imports and SUVs in addition to the traditional Japanese compact cars.
The car pictured here is a 1995 Mitsubishi Eclipse GSX, and has, to date, undergone not one, but two project car facelifts in the HKS garage. It was the company's booth car at the SEMA show in 1995 and the L.A. Auto Show in 1997. During this period of time, it sported a quasi-drag setup; quasi meaning it looked like a drag car, with a fully stripped interior, rollcage and racing slicks at all four corners, but didn't have the motor to match. Ryan Nufable, a sales supervisor at HKS USA, saw the car before he ever went to work for the company and decided he would like to own such a vehicle. When he actually went to work for HKS, he learned that the car had been returned to factory condition and was up for sale.
Nufable's aims were not to make some fire-breathing, track-only vehicle; his goal was to make a fire-breathing, street-legal daily driver. As even the most dull-witted pseudo-tuners know, the key to straight-line acceleration and overall speed is the car's engine. Accordingly, Nufable attacked the Eclipse's engine bay with an array of bolt-on parts from HKS, most prominent among them being intercooler and turbo upgrades. The stock turbo has been replaced with an HKS GT25 Sport Turbo Upgrade, a T3/T25 hybrid with nine clipped turbine blades as opposed to the stock unit's 10. These blades, which are also slightly larger than those on the factory turbocharger, combined with GT-style wheels, allow for slightly increased airflow, which translates, in turn, to a significant increase in engine output.
To keep the compressed charges cool and the system running efficiently, the factory intercooler was replaced with a custom unit about three times its size. This was fabricated by welding two 300ZX cores together, and is, unfortunately, a one-off piece that cannot be found in HKS' product catalog. Exhaust gases are ushered out through a stainless steel HKS downpipe that features two separate chambers, one for the wastegate and one to drive the turbine wheel. The piece is actually a Japanese-spec HKS part for the Mitsubishi Lancer that fit into the Eclipse with minimal modifications. It allows for optimal exhaust flow, minimizes turbo backpressure and actually lets the turbo spool slightly faster, according to Nufable. Excess pressure is liberated by an HKS Racing Blow Off Valve Type II, which is a racing-type bypass valve with a full aluminum body and single pull-type valve that can accommodate up to 35 psi of pressure. Rounding out the package is a Random Technologies high-flow cat and HKS Hiper exhaust system with a stainless-steel muffler and tip.
With such dramatically augmented airflow capabilities, attention was prudently turned to the car's ignition and fuel delivery systems. An HKS Vein Pressure Converter (VPC) has replaced the factory airflow meter, which reads manifold pressure and mimics the factory unit's electrical signal, but not its restrictive mechanical design. The VPC also allowed Nufable to easily dial in his desired air/fuel mixture.
Juice is supplied by an HKS external fuel pump upgrade and 550cc injectors. Ignition spark is masterminded by an HKS Twin Power Ignition Amplifier, a distributorless type ignition, and reaches the combustion chamber via Magnecor 8mm silicon plug wires and high-temperature HKS S35G Super Fire iridium spark plugs. All of this is tied together and monitored by a G-Force ECU upgrade and engine management software
The car's exterior has seen a number of improvements as well-most obvious among them is the 1997 front bumper and headlight assembly. The later assembly has been upgraded with Koito white-beam headlamps, on both high and low beam settings. Since these pictures were taken, Pilot Motorsport fog lights have been installed in the lower fascia.
The suspension has also been upgraded to keep the car solid under heavy-load acceleration. The stock springs and shock absorbers were swapped out and replaced with Eibach Sportline springs and GAB Super HP adjustable shocks, respectively. Volk Racing TE37 Diamond Black wheels and super-grippy Toyo Proxes T1-S tires (235/40/18) make up the running gear.
The car's interior, aside from being totally reassembled from the floorpan up with the factory innards and upholstery, sports an array of engine-monitoring electronics so Nufable can keep tabs on his car's high-strung engine. Two new gauges are mounted in the cabin, a 60mm boost meter and a 46mm EGT meter, both from HKS. Another very trick addition is the HKS Electronic Valve Controller IV (EVC IV), mounted directly below the Sony stereo head unit. The EVC IV allows boost pressure to be adjusted from inside the cabin (and, apparently, while the car is moving). It features four settings: Off (10-psi default setting), Low (15-psi), High (20-psi) and Scramble (approximately 21.5-psi). Nufable relates that normal everyday driving takes place at the low setting, but when necessity calls for him to flex his GT25's mechanical muscles, he switches to high or scramble with absolutely no noticeable side effects.
While Ryan Nufable's black Eclipse has not as yet seen a legitimate dyno run, he has computed a makeshift horsepower figure based on his best quarter-mile trap speed, 104 mph. Running turbo boost at its maximum setting via the EVC IV (about 20.31 psi), Nufable rates his power at approximately 325 hp. But is he satisfied? No. Future plans include replacing the turbo yet again with a low-friction ball-bearing type, as well as hi-po cams and perhaps a few other choice internal engine mods. With the full fury of the HKS parts warehouse behind him, it wouldn't be too far off to say the sky's the limit.