It may be hard to believe, but there are still some people left in this world that haven't heard of JUN Auto Mechanic. One of Japan's most well-known tuners, JUN has applied its horsepower-inducing magic to such cars as the Skyline GT-R, Lancer Evolution, Fairlady/300ZX, Impreza WRX and Silvia. With a keen eye set on building shop vehicles that are the complete package through and through, JUN Auto regularly takes its demo cars out and proves them at the Bonneville Salt Flats, Tsukuba Circuit and on the drag strip.
As a division of parent company Tanaka Industrial, JUN Auto benefits from years of experience developing and manufacturing automotive parts. In the precious few years since its inception, JUN has steadily risen through the ranks of Japan's elite by proving that its products are more than just conceptually designed pieces. This was no more apparent than with JUN's stable of brilliantly colored project cars. The blazing yellow and forest green theme has been a JUN trademark for more than a decade, appearing on the Super Lemon R33 Skyline, the U.S.-stomping Hyper Drag EK Civic and the 2.5-liter Super Lemon WRX. Bright and eye-catching, the paint job screams out like a danger sign, warning all on-track opponents to check their rearview mirrors for the yellow beast rapidly approaching.
Although the strut-suspended DC5 Integra platform has proven more difficult to tune than the DC2 design for many tuners, JUN Auto undertook the task with relative ease. Having already eked out impressive results from the EK Civic and the fourth-generation Prelude, JUN is no stranger to the front-drive Honda world. A regular at Tsukuba Circuit time attack events, this 2005 Integra Type-R has already recorded a 1:02 lap time during shakedown. To put that into perspective, if you read our cover car article then you know that the overall lap record for a production-based car is held by the insane carbon-bodied HKS TRB-02 Lancer Evolution VIII with a time of 54.74-seconds. With results this good coming out of a naturally aspirated, front-drive platform, JUN Auto deemed this car, known as the Super Integra DC5, worthy of its ferocious yellow looks.
The most revered of all Honda namesakes, the Type-R badge is applied only to those models that are designed to be true driving performance machines. The DC5 Integra Type-R comes to the table packing a 220 hp 2.0-liter engine, six-speed transmission, Brembo brakes and Recaro seats. For JUN's track attack however, even Type-R parts wouldn't cut it. The K20A powerplant uses a square 86 mm bore and 86 mm stroke to achieve its twin liters of displacement, and JUN's custom prototype pistons retain the stock bore size. The rest of the bottom end, including the crankshaft and connecting rods, remain stock Honda Type-R.
Up top, one-off JUN prototype camshafts spin on JUN prototype valve springs. A JUN carbon fiber airbox feeds the stock Type-R intake manifold load after load of air, which is all later expelled through a JUN 4-1 header and 70 mm titanium exhaust system. The fuel system remains stock but JUN has tuned the entire setup with a GReddy E-Manage Ultimate engine management system. Still in development and eagerly awaited by legions of Honda owners, JUN's custom camshafts help this DC5 lay down 256 hp at 8500 rpm and 170 lb-ft of torque at 6400 rpm on JUN's engine dyno.
With a fatter, broader torque curve to show for their efforts, JUN Auto chose to utilize a Cusco clutch in combination with the stock flywheel to harness the greatest amount of power. The stock limited-slip differential has been changed out for a tighter Cusco RS one-way differential, while gear banging has been made more frequent thanks to the ultra-short 5.062:1 final drive ratio. With a small displacement and no turbocharger to lend a helping hand, JUN's batch of drivetrain modifications seek to keep the DC5 high in the rev range and deep in the heart of its powerband.
Complementing the high-revving powerplant and short six-speed gearbox is the stiffness of the Type-R chassis, a factor that is always important for handling and response. Stiffened further by a full rollcage and a custom welded front tower support bar, this DC5 Integra is rigid enough to withstand the pounding of custom JUN-spec'd Zeal Super Function adjustable coilovers. In the front, JUN Auto uses custom upper mounting plates and lower control arms to dial in the perfect amount of camber, caster and toe for the Yokohama Advan A048 tires. To permit proper turn-in and front-drive balance, JUN uses skinny 215/45/17 rear tires with a wider 245/40/17 front tire size.
To aid the aerodynamics in high-speed corners, JUN applied their own front bumper, side skirts, carbon fiber hood, rear under spoiler and GT wing. After installation, the entire Type-R was covered in the familiar yellow and green paint scheme of JUN Auto. Complemented by a set of 17x8.5-inch front and 17x7.5-inch rear Advan TCII wheels, the exterior bodywork is both aggressive and functional, a potent combination at any time attack event.
Inside the cockpit, there isn't a whole lot of anything to look at, unless you count the professionally prepared racecar setup. Gutted of all interior panels, window glass and sound deadener, this DC5 is equipped with a single carbon-Kevlar Bride racing bucket, dual Defi-Link Display units and a heavily dished OMP steering wheel. Designed around lightness and control, the cabin has been modified with all of the essentials for the driver to remain in direct connection with the asphalt of Tsukuba Circuit.
With corner-scorching speed far surpassing what you'd expect of any naturally aspirated front-drive car, the JUN Auto Type-R has solidified its place on the hallowed corners of Tsukuba Circuit. More than just a pretty yellow and green paint job, the Super Integra DC5 represents some of the core principles of JUN Auto: Build and tune a car, take it to its full potential and then prove its worth. Right on the edge of the one-minute barrier at Tsukuba Circuit, the Super Integra DC5 has proven plenty, and yet JUN Auto is already asking for more power and more speed. Sounds good to us.