1/8-SCALE 4WD NITRO RACING BUGGY | KIT
PHOTOS BY JOEL NAVARRO
Tekno scores with a competition nitro buggy built to take on the best
Tekno RC rode the wave of the brushless motor and LiPo battery revolution, jumping into the RC industry in 2005 with electric-power conversion kits for popular nitro vehicles. They continued making accessories for seven years before offering the first complete Tekno car, the EB48 (“electric buggy 4WD 1/8 scale”). The EB48 was the first electric 1/8-scale buggy designed as an electric model from the start, rather than a retrofit of a nitro model. Less than two years later, after releasing the SCT410 short course truck, the company unveiled four new vehicles at the 2013 RCX show, including the NB48 (guess what the N stands for) — and announced that they were going nitro racing. Rather than reinvent the wheel, Tekno RC started with what they learned from the EB48 and focused on improving what they felt were the best characteristics of the current cream-of-the-crop vehicles. With fresh ideas and new designs, Tekno melded concepts together in an attempt to create a world-class contender. The car showed plenty of promise in its public debut at the 2014 Dirt Nitro Challenge, which only made me more excited to drive one!
Item no.: TKR5300
Width: 12.1 in. (308mm)
Ground clearance: .98 in. (25mm)
Length: 19.6 in. (497mm)
Wheelbase: 13.0 in. (330mm)
Weight (as tested): 7.2 lb. (3260g)
Chassis: 3mm hard-anodized aluminum
Type: Lower H-arm with turnbuckle camber link
Inboard camber link positions (F/R): 6/6
Outboard camber link positions (F/R): 2/4
Shock positions, towers (F/R): 4/4
Shock positions, arms (F/R): 3/3
Bodies: Threaded aluminum, 16mm bore
Shafts: 4mm shafts
Volume compensation: Bladder
Type/ratio: 4WD with front, center, and rear differentials/2.50:1
Clutch: Centrifugal 4-shoe
Differential: Oil-filled bevel gear
Driveshafts: Universal joint
Bearings: Rubber sealed
WHEELS AND TIRES
Wheels: Not included
Tires: Not included
Body: Clear Lexan type/white nylon plastic wing, painted by Fatty Grafx
TEST GEAR (NOT INCLUDED)
Transmitter: Airtronics M12 FHSS-4 2.4GHz Radio System
Receiver: Airtronics RX-472 2.4GHz FH4T 4-channel
Engine: REDS Racing R5 .21 5-Port Off-Road Competition Buggy Engine
Steering servo: ProTek R/C 170S “Chad Bradley Team Edition — High Speed” Digital High Voltage Servo
Throttle servo: ProTek R/C 170T “Chad Bradley Team Edition — High Torque” Digital High Voltage Servo
Receiver battery: ProTek R/C 7.4V 2300mAh LiPo Flat Receiver Battery Pack
Fuel: Byron Originals 30% RACE 3000 Gen2, quart
Tires: Pro-Line Blockade, X3 compound premounted × 2
In an effort to get everything right the first time, Tekno even tested several combinations of tank lid springs and seals!
A chunky aluminum steering rack bolts to dual bellcranks with a heavy-duty adjustable servo-saver for smooth steering, with plenty of Ackerman and bump-steer adjustment possibilities. Virtually everything on the car that needs to move does so on ball bearings — including the CNC-machined aluminum throttle and brake linkage! The clunk-style fuel tank has raised edges, and an overflow fuel outlet makes sure that any spills during overzealous pit stops don't end up soaking the brakes and other vital organs. Though no tires or wheels are included, the NB48 does come with a white plastic rear wing and an extreme cab-forward body with large, flat surfaces for aerodynamic stability.
Everything about the front and rear suspension, including the 16mm big-bore shocks, is borrowed from the EB48 electric buggy.
Tekno RC was allowed so much time to focus on the chassis because they already had the awesome front and rear suspension clips from the EB48 that they could bolt right in place. Tall shock towers that feature a plethora of shock and camber link mounting positions provide the sturdy structure for buttery smooth 16mm big-bore shocks with threaded bodies and tapered pistons, which allow for faster rebound to keep the tires connected to the track surface. The lower suspension arms are both bulky and tough — and because the webbing of the arms is closed, dirt is less likely to get trapped in and around the suspension. Rear pivot block bushings allow for adjustments to anti-squat and toe-in for differing track conditions, as do the adjustable length rear arms — the arms and hubs have two different hingepin locations, which changes the effective length of the arm.
The NB48 uses the same suspension assemblies as the electric EB48, but everything between the gearboxes is new and nitro-specific.
Much of Tekno RC's focus when examining other nitro buggies revolved around the chassis. While many cars hold their heaviest components close to the centerline, in order to maximize cornering agility, but according to Tekno, some of them go too far and overload the right side. Tekno settled in the middle of the road and fastened the motor mount close to the center while maintaining equal side-to-side balance. The motor mount itself has two different locations — the default “front” position, or 18mm farther toward the rear, which significantly alters the weight distribution for more traction on rough and slick surfaces. Both sides of the chassis sport molded mudguards, with the right-side unit also housing the radio tray to keep the weight as low as possible. The front and rear overhangs — as in, how much the chassis protrudes in relation to the axles — are among the shortest in the 1/8-scale class for more clearance when traversing bumps and jumps.
TALL SHOCK TOWERS THAT FEATURE A PLETHORA OF SHOCK AND CAMBER LINK MOUNTING POSITIONS PROVIDE THE STURDY STRUCTURE FOR BUTTERY SMOOTH 16MM BIG-BORE SHOCKS
OFFSET SHAFT-DRIVE SYSTEM
Note the reliefs in the chassis, and the curve in the chassis brace to accommodate the offset driveshaft.
The most important part of managing the NB48's left-to-ride weight distribution was determining the optimal drivetrain layout, and Tekno RC designed on a “mid-offset” rear bulkhead and ring gear. The rear diff's pinion gear is slightly off-center, allowing the center driveshafts to remain as straight as possible while still moving the center differential to the right side of the chassis in order to position the engine closer to the center of the car. Though they're often aftermarket options for other cars, lightened gears and outdrives are used on the front, center, and rear oil-filled differentials to reduce rotating weight for faster acceleration, and similarly top-spec steel brake discs with semi-metallic pads were chosen for fade-free stopping power. Rather than riding on the top, the linkage for those brakes is mounted to the right side of the center diff, which moves their weight lower in relation to the rest of the chassis, and a turnbuckle makes it easy to adjust front-to-rear brake bias. To get things moving, an adjustable four-shoe centrifugal clutch transfers the power from your choice of engine to the center differential.
BEHIND THE WHEEL
I selected Heritage R/C Park in Chula Vista, CA, as my test track for the NB48, and I prepped the buggy with a full complement of pro-caliber gear to make sure I experienced its full performance potential. The engine is the most important spec of course, and I installed a REDS Racing R5 — the same engine that 2010 IFMAR World Champ Cody King chooses. Once broken in and tuned to kill, the engine locked up the aluminum shoes on the NB48's clutch and sent the buggy rocketing down the long straightaway. The car launched so hard that it caught me off guard, but that acceleration made it easy to clear the track's big jumps and nail the timing on the tricky step-on-step-off section in the center of the track. The NB48's plush dampers and well-sorted stock setup soaked up the bumps leading up to the face of the jump and settled quickly after the car succumbed to the Earth's gravitational forces. Even when intentionally over-jumping the large double in the center of the course, the NB48 landed on its feet like a cat. Even through the tough whoop section along the right side of the track, the NB48 simply swallowed up whatever obstacle stood in its way.
Equally as impressive as the NB48's jump and bump handling was its ability to carry corner speed, which became even easier to control once I removed the shorter of the two rear chassis braces. The added flex gives the buggy more rear traction, and while it may be an advantage in very high-bite situations, the stock setup calls for it to be omitted. Even with more steering throw available by adjusting the buggy's steering stops, the NB48 turns in hard and carries that aggressive direction-changing authority throughout the corner, unfazed by any bumps or varying track adhesion levels. On every corner of the track, from the sweeping corners at both ends of the straightaway, to the tightest infield 180s, the NB48 went wherever I pointed it. Within my first few tanks on the track, I felt comfortable pushing the car and my own abilities.
Solid parts quality makes for easy assembly
Fresh design ideas help the car stand out
Lively on-track behavior begs to be driven hard
Wheels not included
It's clear that Tekno did their homework before designing the many necessary components to create such a track-ready racer. While the NB48 shares its suspension with the electric buggy that preceded it, don't call it a conversion. Everything between the front and rear gearboxes is new, and many features like the side-mounted brake linkage and dual-position motor mount are innovative. Assuming that the NB48 follows the precedent set by the EB48 and SCT410 vehicles of being durable and high quality after hours of run time, which our testing time would suggest, this car will be a hit at nitro races and among drivers of all levels.