OFNA Ultra LX Pro

Radio Control Car Action, Mar 2003 by Vogel, Greg

track test

1/8-SCALE NITRO

I REMEMBER MY FIRST TIME AS IF IT WAS YESTERDAY. Don't get me wrong-I waited a long time before I did it. Back when I was 16, not a lot of kids were doing it. They just didn't know how. But I did some reading about it, and yes, I even watched a few people do it before I attempted to do it myself. I was a little nervous at first ... but I just took a deep breath. stuck the glow igniter on, pulled the cord, and the engine fired right up. (If any of you thought I was talking about anything other than nitro cars, you're sick.)

The big-block buggies of the past were intimidating machines, but the OFNA guys took it upon themselves to make it easy and exciting to get into with a broad line of RTR buggies. The Ultra LX Pro is the latest, and it arrives assembled; only a few easy steps are required to get the buggy from the box to the backyard. OFNA equipped the car with a large-displacement .25 engine to meet your need for speed, a heavy-duty, long-travel suspension for sick-air jumping, and knobby-treaded tires to tear up grass and roost dirt. It has even thrown in most of the accessories that typically have to be purchased separately with other vehicles in this class. But enough of that; let's see whether this buggy is right for your first time.

KIT FEATURES

CHASSIS. The LX Pro is built on a 3mm aluminum chassis that's coated with an attractive, gray-anodized finish. Plastic guards are bolted to the chassis, and they curve high up inside the body to keep out dirt, stones and other debris. An enclosed electronics box protects the receiver and battery holder; water and dirt will have a hard time finding a way inside. OFNA went the extra step to include a silicone cover for the on/off switch to protect it from the elements. Rounding out the platform are a 2mm-thick, blue-- anodized aluminum radio tray, a steering-- bellcrank brace and a rear-chassis brace. To prevent the front end from collapsing in an impact, a plastic "flying buttress" stiffener reaches up from the main chassis and is attached to the bellcrank brace.

DRIVE TRAIN. Like all other OFNA 1/8-scale buggies, the LX Pro is equipped with a 3-differential shaft-drive system. In the center diff, the LX boasts a solid-steel spur gear, and the steel ring gears on the front and rear diffs each contain four spider gears. The diffs are built with O-ring seals and are factory lubed with grease; since they are sealed, this allows you the option to fill the diffs with silicone fluid as a traction-tuning aid. Steel dogbones link the three diffs and reach out to the rear wheels, but the front end gets a pair of universal-- joint axles that prevent chatter while steering. All four corners have 6mm stub axles and 17mm hex hubs, so just about every available aftermarket rim will fit. Rubber-sealed bearings are used throughout the drive train to keep out dirt to extend the time between routine maintenance sessions.

Front and rear disc brakes with 3.5mm fiber rotors and steel calipers do the stopping, and factory-installed thumbwheel-linkage adjustment knobs make it easy to fine-tune the front and rear brake bias.

SUSPENSION AND STEERING. The LX Pro is outfitted with long-travel upper and lower wishbone arms in the front and a lower H-arm with an upper link in the rear. The rear is fitted with a zmm swaybar to improve stability, but the front end is fully independent. Up front, the wishbone arms hold the Pro's cast steering knuckles, and steel turnbuckle linkages allow toe adjustments without disassembly. To adjust the camber settings, you will have to remove the top kingpin because the upper arms use threaded rods instead of turnbuckles.

The large-bore shocks are as good as they get. Instead of using clip-on collars that could pop off, the aluminum shock bodies are threaded, so spring preload is adjusted easily. Silicone boots protect the shock shafts from harmful, component-destroying dirt. A heavy-duty servo-saver is integrated into the buggy's dual-bellcrank steering system, which combines thick plastic 'cranks with a blue-anodized aluminum drag bar.

ENGINE AND ACCESSORIES. Want a big engine? Would a .25 be big enough? The LX Pro's Force mill displaces .25ci (instead of the usual .21), and it delivers more low-end torque. An extra-large, heat-sink head mates with the large, 5-port chrome sleeve. Inside the engine, you'll find a wide-- face piston; a machined connecting rod with bushed big end; a dual ball-- bearing-supported crankshaft with a ported counterweight that helps the fuel/air mixture pump through the engine more efficiently; and an aluminum-body, 2-needle slide carburetor.

OFNA equipped this powerplant with impressive components. The single-chamber, less efficient tuned pipes have been canned for a more expensive power-improving dual-chamber tuned pipe; its spring-mounted exhaust manifold will flex on impact instead of coming apart as zip-tied couplers can. Clean air enters the Force .25 engine through a foam-element air filter, and its silicone elbow is secured with a wire standoff. OFNA's racing-style, 125cc fuel tank feeds the system, and an internal stone-type filter prevents crud from entering the carb; a molded-in splashguard keeps fuel away from the brakes. BODY, WHEELS AND TIRES. Don't check the source guide to find out which pro painter did the artwork on the body. The LX Pro comes with the factory-- finished body you see on these pages, and we're sure you'll agree that OFNA is busting out some of the best looks in RC. OFNA also hacks the body for you. The openings for fuel-tank access and engine clearance have been cut out, but we had to do a little trimming so the body would clear the rear shocks property.