Among the five Japanese sports cars American high school boys fantasized about during the early 1990s, Mazda’s RX-7 is perhaps the most unique. Unlike Acura’s NSX, it was sequentially turbocharged, and in contrast to the Toyota Supra, Nissan 300ZX and Mitsubishi 3000GT VR-4, it was the only one to not feature pistons or connecting rods. The third-generation RX-7 with its Wankel rotary powerplant that was sold in the U.S. for the 1993-1995 model years epitomized Japanese ingenuity and is precisely what lures people like Vidjai Doerga into owning one.
The body style baited Vidjai the first time he saw it along the Miami shoreline more than 15 years ago. He wouldn’t call one his own for several years, but with its sultry lines that converge into sleek, pop-up headlamps and its technical marvel of twin turbochargers that result in 255 hp, Mazda’s FD-chassis RX-7 isn’t one to be forgotten. A first for any Japanese automaker, the company’s sequential turbocharger system was the makings for automotive legend. Partially developed by Hitachi, the layout is composed of a single turbocharger that begins spinning full song at 1,800 rpm and is later joined at 4,500 rpm by its accomplice. The results are a broad acceleration curve and among the most harmonious sounds you’re likely to hear come from between two wheels.
None of this escapes Vidjai, which is why, despite his aspirations for nearly doubling his Mazda’s power output, a single-turbo conversion or eight-cylinder engine swap never happened. Instead, he pursued more power with help from matching GReddy TD05-18G turbochargers. Manufactured by OEM supplier Mitsubishi Heavy Industries exclusively for GReddy and used as an aftermarket alternative for just about every make imaginable, TD05 designates the assembly’s turbine side and 18G its compressor. A rare RE Amemiya exhaust manifold of which only six exist, according to Vidjai, was also unearthed from the depths of the Japanese tuning company’s warehouse, and serves as a beacon for when this RX-7 build went, in its owner’s words: “haywire”.
“It wasn’t really supposed to go this far,” Vidjai says. “After getting the manifold, everything changed.” Right about now is when the 22 year-old student’s modest, mid-’90s sports car build turned into something more. The engine was disassembled with a 500whp target in sight, a standalone engine management system from A’PEXi was added, and, through his day job resources at wheel manufacturer ISS Forged, a one-off set of custom rims was machined solely for his RX-7. “That’s one of the perks of working for a wheel company,” he says while trying to contain his excitement ... unsuccessfully.
Even at four years-old, when America was introduced to the RX-7, Vidjai knew it was something special. “I’ve been around cars since I was a toddler,” he says. “I started out building cars with my dad years ago.” If you ask Vidjai, though, late nights playing Gran Turismo is what really attracted him to Mazda’s last true sports car, and despite internet warnings of how volatile rotary engines can be, he pursued one anyway. “It was a Porsche-killer. It was so far ahead of its time.” That’s all Vidjai has to say about why he wanted one. And about those supposedly volatile rotary engines, well, Vidjai sums it up best: “People don’t really understand rotaries. You can’t treat them like a piston engine. There are a lot of misconceptions about them.”
Such misconceptions originate not from the shortcomings of an engine design that operates on merits of efficiency and simplicity but from the abuse any 20 year-old factory turbocharged sports car is likely to have endured. All of this is precisely why Vidjai waited nearly three years for the right combination of seller and car before settling. “The lady didn’t really know what the car was,” he tells of the previous owner, going on to explain how, after a thorough investigation, he’d come to the conclusion that it had been several years since the never-modified engine had spun anywhere past 3,000 rpm or, let alone, put its second turbo to use. “The secondary turbo’s valve was sealed shut from never being used. I had to chisel it off,” he says. Still, according to Vidjai, it was the cleanest RX-7 he’d ever seen, and with only 67,000 miles accumulated, a better specimen of Mazda’s final U.S.-bound turbocharged sports car there never was.
The modifications don’t stop underneath the hood. Vidjai teamed up with nearby Miami Autoworks to overhaul the car’s outside. A hard-to-find URAS Type-GT bumper was added up front along with widebody fenders all around from FEED. An oversized Garage B.B. carbon-fiber wing and RE Amemiya carbon-fiber bits, like a rear diffuser and taillight covers were also installed—all of which give Vidjai’s RX-7 a look all its own. While the entire car was assembled nearly on his own, save for welding and fabrication, he admits that it would never have looked as good as it does now without the help of the good people at Miami Autoworks and a couple of other accomplices: “The car’s design, layout, and all-around awesomeness would never have happened without my big brothers Janoy Fuentes and Steven Gietel.”
“I built this car to track it, and that’s what I plan on doing,” Vidjai says of what’s next. An SCCA-approved rollcage and a tune good for 500 whp are also on the agenda. Consider the high school fantasy accomplished.
1994 Mazda RX-7
Occupation Student, ISS Forged USA sales manager
Engine Extreme street port; 2mm Rotary Aviation Super Seals; GReddy TD05-18G turbocharger (2), compression tube and Type R blow-off valve; GReddy-spec TiAL F38 wastegate (2); custom V-mount intercooler; RE Amemiya twin-turbo exhaust manifold; custom four-inch exhaust; Vibrant Performance four-inch resonator and muffler; Walbro 400lph fuel pump; Full Function Engineering primary and secondary fuel rails; Injector Dynamics 850cc primary fuel injectors; FiveoMotorsport 2,200cc secondary fuel injectors; Turbosmart fuel pressure regulator; Earl’s AN fittings and lines; Hose Techniques vacuum lines; Koyo aluminum radiator; Pettit Racing air separator tank; Touge Factory billet-aluminum pulley set; Tweakit Racing idler pulley kit; Cusco oil catch can; AEM Smart Coils (4); Garfinkle engine torque brace; IR Performance polyurethane engine mounts
Drivetrain SPEC Clutch stage three clutch
Engine Management A’PEXi PowerFC engine management with FC Commander; GReddy PRofec e-01 electronic boost controller
Footwork & Chassis TEIN MonoFlex coilovers and EDFC; SuperPro bushing kit; GReddy front shock tower brace; Banzai Racing differential brace
Brakes StopTech slotted Big Brake Kit (front) and slotted Sport Kit (rear); Mazda 929 master cylinder; Motul RBF660 fluid
Wheels & Tires 18x10" (front),18x11.5" (rear) Blonix by ISS Forged SpeedSter RS with Retro Step lip; 265/35R18 (front), 295/35R18 (rear) Continental ExtremeContact DW
Exterior URAS Type-GT front bumper with canards; FEED widebody front fenders, wide-body rear overfenders and carbon-fiber side steps; RE Amemiya carbon-fiber rear diffuser and carbon-fiber taillight cover; HotWater Labs custom headlight conversion with brake ducting; Garage B.B. 1600mm carbon-fiber GT wing; APR Formula GT3 carbon-fiber mirrors
Interior Kirk Racing four-point rollbar; Bride Vios III Low Max seats and Low Max seat rails; Car Make T&E Vertex steering wheel; B&M short shifter; JDM Mazdaspeed shift knob; Dynamat trunk kit; carbon-fiber-wrapped A-pillars with custom gauge pod; Innovate Motorsports wideband air/fuel, oil pressure, and water temperature gauges
Thanks You My amazing girlfriend, Monica, my dad, Turhane Doerga, and my family, who put up with the late nights and excessive spending; Frank Gonzalez for helping from the start; Joe and Phillip at HotWater Labs; the Trash Talk crew and Vision Autos for the motivation to finish; Rolo at Central Florida Turbo for the tuning; Aaron at Full Function Engineering; Nelson and Leo at StateOfStance for the support; the South Florida Rotary crew and Rx7Club.com members for the rotary support and knowledge