OFNA Ultra GTP RTR

Radio Control Car Action, Jun 2001 by Gonzalez, George M

1/8-Scale Buggy

IDA Rife What do I get when you wrap a low-slung GT-1style on-road body over a race-proven, the Street 1/8-scale fuel-powered off-road buggy? You get an all-new class of on-road vehicle OFNA calls the "Ultra George M. Gonzalez GTP? The folks at OFNA took the concept even further by modltying the front suspension geometry for on-road duty and offering extensive factory assembly that Includes the installation of a high-quality Alrtroniq Blazer Sport radio system.

If you like hop-ups, the Ultra OTP is loaded with hot features such as fron rear swaybars, aluminum-body shocks, turnbuckles, constant-velocity (CV) fr axles, a tuned pipe and header and much more. I was eager to take the Ultr GTP on a test drive; care to join me?

DATA CENTER

VEHICLE TYPE 1/8-scale, .21 powered, 4WD street racer BEST BUYER Beginners and experts who are looking for a fast and fun recreational on-road vehicle

KIT RATINGS (poor, satisfactory, good, very good, excellent) Instructions Satisfactory

Parts finish Good

Durability Excellent

Overall Performance Good

SPECIFICATIONS

MANUFACTURER OFNA

MODEL Ultra GTP

SCALE 1/8

STREET PRICE $399.99

DIMENSIONS

Wheelbase 12.625 in. (320.67mm)

Width (F/R) 11.875 in. (301.62mm)

WEIGHT

Total, as tested 132 oz. (3,742.2g)

CHASSIS

Type Double-deck Material Aluminum

DRIVE TRAIN

Type Shaft-drive 4WD

Transmission Ring and pinion gears

Drive Shafts Universals

Primary Clutch bell/spur gear

Drive shafts (F/RI CV axles/ dogbones

Differentials MR) Bevel gear

Bearing type Metal-shielded ball bearings

SUSPENSION

Type (FAQ Double-wishbone/lower Warm upper link

Damping Aluminum-body, coil-over, oil-filled shocks

WHEELS

Type One-piece nylon

TIRES

Type Mounted treaded radials; street slicks (four of each type)

ENGINE AND ACCESSORIES

Engine OFNA/Force .21 rear-exhaust

Starter Pull-starter

Carburetor Slide

Exhaust Aluminum tuned pipe and header

Fuel capacity 125cc

LIKES

100 percent factory-assembled chassis.

Very fast and nimble.

Extremely rugged.

Feature-filled chassis.

Two sets of factory-assembled tir and wheels.

DISLIKES

Body is a little out of scale, doesn't fit any particular class and should be constructed of thicker Lexan.

OFNA makes no attempt to disguise the GTP's off-road roots, and there's no mistaking the suspension and chassis parts for buggy hardware. As you can see, everything is more than beefy enough for road duty. The swaybars are especially welcome on pavement.

YOU"LL NEED for the transmitter and 4 for the onboard electronics) C-size alkaline battery for the included glow-plug igniter Fuel texan-- compatible paint for the body 16-ounce soda bottle (for use as a fuel bottle)

. 2-speed transmission-part no. 35001

Rear CV joints-30071 Graphite radio plate31280 Graphite front brace-31270

building & setup tips

The Ultra GTP chassis arrives completely assembled with the radio gear neatly installed on the chassis. You have only to install the body mounts and front bumper and paint and trim the body. It may seem like a no-brainer, but here are a few tips that will help.

Receiver care. Wrap the receiver in foam or another type of padding before you put it inside the molded receiver box. This will isolate it from engine vibration.

Onboard battery pack. A 4-cell battery holder is included to make getting started easier and more affordable, but it should only be used with alkaline batteries; four rechargeables will have lower voltage and will not allow the servos to operate to the full extend of their capabilities. A 5-cell, 6V NI-Cd or NIMH pack will provide a full 6 volts for the steering and throttle servos.The Ultra GTP is heavy and has to rely on standard servos to maneuver it and operate the brakes, so be sure those servos get a full 6 volts.

Air-filter lube. Before running the vehicle, be sure to lubricate the foam air-filter element with air-filter lube or after-run oil. After every three or four tanks of fuel, clean the filter in warm soapy water and then rinse it thoroughly under running water. When it has dried, relube it and reinstall it.

Fuel spout. If you use a soda bottle as a fuel container, be sure to clean it thoroughly with soap and water and let it dry completely before you install the included fuel spout and fill it with nitro fuel. And be sure to label it "DO NOT DRINK!" Engine break-in. Somewhere toward the back of the manual, you'll find engine break-in instructions. Follow them to the letter and don't take any shortcuts. The engine will be very stubborn for the first three or four tanks of fuel and will have to be restarted frequently.

KIT FEATURES

Chassis. The Ultra GTP features the same robust, double-deck chassis as the Ultra GT/LX and Ultra MBX off-road buggies. A fully countersunk, 3mmthick, blue-anodized-aluminum chassis serves as the foundation. A 2.5mm-thick, blue-anodized aluminum radio plate houses all of the onboard electronics and is suspended above the chassis on five aluminum posts. A two-piece aluminum front chassis brace and a one-piece rear brace increase chassis rigidity significantly, and they're blue-anodized to match the rest of the chassis components. A heavy-duty, twin-bellcrank steering system with a servo-saver built into one of the bellcranks pivots smoothly on aluminum posts. Up front, there's a heavy-duty onroad bumper with a foam body support.