Two hundred and forty-nine mph is fast enough to get you from Los Angeles to San Francisco in just under two hours (provided it's 3 a.m. and the cops are on strike). It's faster than most private planes and helicopters not named Airwolf can go. Two hundred and forty-nine mph is also far too fast for a street-going car, right? "Wrong!" say the speed merchants from JUN. In an exercise intended to showcase their design capabilities, JUN will try to push the envelope of what is considered obnoxiously fast for a street-driven car.
High-speed tests are nothing new for Japanese tuners, whose creations frequently battle for the title of Fastest Street Car on the Japanese highways. In the United States, high-speed contests, such as those held at Bonneville and Muroc Dry Lake, serve as the founding backbone of our hot rod culture. So it makes perfect sense that a Japanese tuner like JUN would want to further its reputation and showcase its tuning wiles on the Bonneville Salt Flats in pursuit of ultimate speed.
JUN's chosen weapon for the assault on the E/BGCC land speed record is the outrageous Akira Supra you see before you; it's certainly unlike any other Supra cruising the planet. Most land speed record-breaking machines are purpose-built, tube-framed missiles clothed in composite bodywork that vaguely resembles the silhouette of a street car. But the Akira Supra started life as a well-worn JZ80 Supra. Its transformation began when the unibody and floorpan were reinforced with a multipoint rollcage for safety and rigidity. The interior is stripped, with the gauges monitoring the engine's vital functions clearly displayed in a carbon-fiber panel across from the driver. The design of the Akira Supra's skin and its aerodynamics have been improved to reduce resistance and increase stability. A fabricated nosepiece helps reduce drag and leaves the Supra looking every bit like a road- going submarine. The hood is made from steel to add weight and efficiently duct air through the cooling system. The car's rear hatch is heavily modified with a fabricated steel spoiler that adds the mass and stability necessary to plant this Supra's ass on the salt at 250 mph. The car's high-speed handling is further aided by a steel underbelly pan, which reduces undercar turbulence and provides a bit of downforce.
The heart of any JUN product, and the most vital component of any land speed effort, rests under the hood. This may just be the most potent Supra motor on the planet. All of the motor's internals—such as forged JUN pistons attached to forged JUN connecting rods that swing on a billet steel crankshaft, raising engine displacement to 3.2 liters—are suitably beefed up to survive prolonged exposure to high-boost conditions. Meticulous block preparation and aggressive cylinder head porting also played a vital role. Air is pressurized into this O-ringed cylinder head assembly by a pair of Trust T78-29D-14cm turbochargers bolted onto a custom-fabricated, stainless steel exhaust manifold. The turbos pressurize a prototype JUN GT intake manifold with up to 50 psi of boost. A Trust four-row intercooler lowers the intake-charge temperature as the force-fed air is compressed atop the 8.45:1 pistons.
Meeting the fuel demands of such massive helpings of air are five Bosch fuel pumps, twelve JUN 890cc injectors, and an HKS V-Pro fuel computer. The word prototype appears all over component descriptions related to this motor, from the radiator back to the muffler. JUN's unique blend of engineering, fabrication, and passion helped produce a motor capable of 1,300 hp. Pretty stout for hunks of tin and cast metal that started life on an assembly line.
Four digits' worth of horsepower have a way of exposing the weaknesses in a stock drivetrain. To combat this, JUN uses a custom-built Holinger six-speed sequential transmission and an HKS triple-disc clutch to harness the power to the rearend, which houses a 2.238:1 ring-and-pinion set. The numerically low gearset probably makes this car accelerate with all the willingness of a school bus, but it's just the ticket needed to stretch 1,300hp legs on the way to 260-plus-mph top speeds.
Maybe the nuttiest thing about this Supra is that the factory front fascia can be swapped back on and the car driven to the grocery store for some eggs and a copy of National Enquirer. Not that you'd want to disrespect a car like this with a task as mundane as a Taco Bell run, but the Akira Supra still shares some street Supra DNA. "Street-driveable car" is a loosely defined term in this case, as some of us prefer something in the way of amenities for street duty, like carpet or roll-up windows. For others, the fact that it can be driven off a race transporter and onto a driveway qualifies as streetable. But putting this car on the boulevard would be as great an injustice as forcing Anna Kournikova to play tennis wearing a muumuu. The JUN Akira Supra is a free spirit of a car, more in its element on long, open stretches of dry lake where it would be immune to the wrath of Smokey and his radar pistol.