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Big time!

Big time!

Vieira, Peter

You know who you are. You’re the guy with the 40-ounce Big Gulp. You have a 36-inch flat screen in your room. Your dream ride is a Lincoln Navigator. In short, you like your stuff big. And if you’re into sedan-body, nitro-powered RC action, you’re probably already eyeballing the cars that fill up this spread. These aren’t mere “super-scale” cars; as fast and fun as those .15 powered, plus-size cars are, a guy like you needs more from an RC machine. “More” as in more power (like a .21 engine), more speed (try over 50mph on for size) and more millimeters between the axles. The largest car measures more than 3 feet from bumper to bumper; that big ‘un is the Schumacher Nitro Big 6, which joins the Kyosho LandMax and OFNA Ultra GTP in a three-way battle to see which is the best .21-powered sumo sedan. Shall we?

KYOSHO LANDMAX 2

OFF-ROAD CAPABLE

Consider the

LandMax to be the granddaddy of the .21 sedan class. We dug the car when it first appeared in 1998, and the buggy-based platform has only gotten better, thanks to its Inferno roots. The changes that transformed the 1999 IFMAR World Champ Inferno MP-6 into the even faster 2001 World Champ MP-7.5 also appear on the LandMax 2 chassis, which is basically an MP-7.5 Sports with narrower arms and shorter shocks. Kyosho envisioned the LandMax as a dual-purpose platform that could tackle dirt and pavement, and it has fittingly chosen rally racers as body subjects for the big car: this one’s the Total/Clarion Peugeot 206 WRC version.

DRIVE TIME

In keeping with its rally theme, the LandMax 2 was tested both on- and off-road. In the dirt, the car’s relatively stiff springs and narrow track made it a handful on rough, rutted surfaces, and frequent steering inputs were needed to correct bump-induced heading changes. But on smoother (and more rally-like) surfaces, the LandMax shone with easy-to-control corner drift and just-like-on-Speed Channel dust trails following the car’s every move. On pavement, the LandMax enjoyed more grip but was still highly pitch-able, with oversteer easily controlled by throttle input. In straight-line drag runs, the Max accelerated hard and wound out just a little early (it could probably be geared a little higher), but it was still quite fast as its narrow Peugeot 2o6 body punched a 36mph hole through the air. When the end of the parking lot neared, the LandMax’s dual discs easily hauled the car to a stop with plenty of grab left over for wheel-locking stunt action. Throughout testing, the engine never faltered, but each pit-stop temp check revealed it to be running close to 28o degrees; that’s hot, but no hotter than we had experienced with the GS-ziR without incident. Still, it’s best to rest the car between runs, and as you should with all nitro cars, be sure to cut ample cooling holes in the body (as we did, after we shot the photos).

INSIDE THE LANDMAX 2

1. It’s an Inferno. Fans of 1/8-scale buggies will recognize the Inferno’s 3mm, countersunk aluminum chassis as a direct lift from the Inferno MP-7.5 Sports. It has all the Inferno features: built-in kick-up, “dimples” for lowest possible diff placement, molded side guards, steel-rod braces and a 2mm aluminum radio tray. You also get the buggy’s sealed radio box-a two-compartment deal that makes it easy to access the receiver without hassling with its battery pack (and vice versa). Once you’ve body-clipped the dual hatches closed, nitro gunk is kept away from the goodies inside. A wire rollover hoop is a new addition to the Inferno formula and will help spare the engine from abuse when the action turns upsidedown.

2. Triple-diff pWD. The Inferno connection continues with the drive system that includes front, center and rear gear differentials with plastic housings. Metal ring and pinion gears spin the front and rear diffs, but the spur gear is plastic; I hope it holds up. Kyosho includes a full set of ball bearings to keep everything spinning happily, and dogbone axles are used front, rear and center.

3. Plastic suspension. Unlike the Inferno buggies it was spawned from, the LandMax’s shocks and shock towers are plastic, not aluminum. While that may feel like a step down in cool factor, Kyosho’s heavy-duty “Sport” shocks are indeed tough, and the plastic towers aren’t a liability thanks to their thick cross-section and their compact size.

4. Front and rear disc brakes. One of the nice things about a 3-diff car is being able to adjust brake bias via independent front and rear brakes. The LandMax has lem in the form of drilled 2mm rotors and padded steel calipers. Because the front brake is alongside the fuel– tank opening, there’s a trick splashguard over the brake to prevent fuel spills from contaminating the pads.

5. Aluminum tuned pipe. The LandMax’s pipe isn’t exactly what you’d expect when you hear the words .aluminum tuned pipe.” Instead of a one-piece design, the pipe is actually a cast, three-piece, screw-together assembly. An O-ring seals the pipe’s two primary sections, with a separate convergence cone in between. A silicone elbow joins the pipe to a bolt-on manifold.

6. Rally rubber. Realistic tires with what is best described as an “L” tread fit onto LandMax-specific, one-piece, 5-spoke wheels. The wheels have slots to accept the tires’ flat beads, ‘A-scale buggy-style, but foam inserts are not supplied; instead, the tires rely on their relatively low profile and firm rubber construction for marginal support.

OFNA ULTRA GTP

READY TO TUN

OFNA went for a wider is better approach with the Ultra GTP, which is a lowered, road-going version of the Ultra– series off-road buggy platform. The buggy’s long arms are left intact on the GTP, and the wheels are buggy size, too. Two sets of rubber are included, so you can outfit the Ultra GTP with slicks or treaded tires to suit the conditions at hand. The fat tires, wide-track arms and low stance combine to give the Ultra a suction-cup grip on the pavement, and with its humungo body in place, the OFNA car rivals the mega– massive Schumacher Big 6 for sheer size. It’s really closer to I than ‘A scale.

DRIVE TIME

Despite the Ultra GTP’s heaviest-car-tested title, the Force .21 delivered impressive, right-now acceleration that made the Viper-body Ultra truly appear to be V-io-powered. Much of that off-the-line rip comes from low-ish gearing, as evidenced by the car’s wound-out top speed of 40.6mph; there’s more speed on tap if you gear up. Handling-wise, the Ultra GTP is held back by its 94102 “standard” steering servo. We appreciate that it keeps the kit’s cost low and doesn’t drain four AA batteries too quickly, but it just isn’t up to steering a heavy, high-traction, high-speed car with any precision. If you want your GTP to handle its best, an upgrade to a high-torque servo is a must. We went for an Airtronics 94757, which made the most of the Ultra’s wide tires and the chassis’ big footprint. The Ultra is a very quick handler, with minimal body roll, thanks to its front and rear swaybars, but if you steer aggressively at speed, the hefty chassis can overpower the tires’ considerable grip. When that happens, the rear end kicks out, and you have to countersteer and modulate the throttle to keep the car under control-and that’s really where the fun begins. Like the LandMax, the Ultra GTP is most fun when driven past the edge. All the obnoxious stuff you’d be arrested for if you had a real Viper is perfectly legal and 99 percent as much fun with OFNA’s Ultra GTP version.

INSIDE THE ULTRA GTP

1. Underneath, it’s a buggy. OFNA’s Ultra-series offroad buggy is essentially unchanged for its GTP on-road duties. The shock towers are a little lower and a large front bumper has been added, but the GTP is otherwise a buggy in disguise. Nothing wrong with that; you get a 3.2mm countersunk aluminum chassis and shock towers, a 2mm radio tray and chassis braces and ample, plastic stone guards.

2. Steel spur gear. Combine a heavy 1/8-scale buggy chassis with a powerful .21 engine and you get a seriously strained spur gear. Steel is the way to go, and OFNA wisely went ferrous for the Ultra GTP’s all– important gear. Don’t look for a center differential, though; the GTP has a solid “cliff spool” that sends fulltime 4WD power out to the front and rear diffs through steel ring-and-pinion gears. Dogbones spin the rear wheels and link the diffs to the spur gear, but the front end gets brightly plated universal-joint axles, and like just about all big-block machines, the GTP has a full set of ball bearings.

3. Aluminum shocks. Make that large-diameter, blue– anodized, long-travel aluminum shocks. Silicone boots help keep their shafts clean, and thick 2.5mm towers give them a stiff base. The shocks are pinched by buggy-width upper and lower wishbone arms up front and lower H-arms with turnbuckle camber links in the rear. Pivot-ball steering arms and ZmM front and rear swaybars round out the fully adjustable suspension.

4. It’s painted. Once you crack open the Ultra GTP’s box, you’re only about half an hour from tearing up the local parking lot. That half hour will be spent trimming and decaling the painted body, which can be had in Dodge Viper, Mercedes CLK, McLaren Fi and Celica rally versions. Zegers RC Graffixx custom-painted clear shells for our tests; the factory bodies are shot in one color and come to life with decals.

5. Wheel deal. Chrome, 5-spoke wheels set off with vivid blue axle nuts give the Ultra GTP a convincing street look, and OFNA glues the tires for you-all eight of them. Two full sets of sneakers are included: one set of slicks, another with V-treads.

6.100 percent RTR. The Ultra GTP is the only ready-to– run of the group and includes an Airtronics Blazer radio system with 94102 servos, glow starter and fuel bottle. The budget Airtronics transmitter is as reliable as ever, but the servos would be more at home in a tighter vehicle. We’ll see how they do.

Schumacher

NITRO BIG 6

BIGGEST & FASTEST

In this battle of big, the Schumacher Nitro Big 6 is clearly the leader in large. With a whopping 15– inch wheelbase and more than a foot between the left and right sidewalls, the Big 6 has a major presence on the parking lot. But don’t think of the Sixer as a portly pavement pounder; beneath the Lotus Elise body lies a lightweight chassis and belt-driven 2WD system that allows the included Thunder Tiger Pro .21R engine to push the Big 6 past 55mph. It handles, too, thanks to wide-track, low-profile rubber and laydown shocks on all corners. The Big 6 is a lot of car for a little money, especially when compared with traditional 1/5- and 1/4-scale rides.

DRIVE TIME

Schumacher made a good choice in spec’ing the Big 6’s Thunder Tiger engine; it started on the first tug and (after break-in) idled like a Toyota Camry. But all family-car comparisons end when you squeeze the trigger and the Big 6 shoots off in a surprising hurry and blasts to its 58mph top speed with three crowd-pleasing shifts on the way. That’s only 4mph faster than the single-speed Nitro Big 6’s we tested back in May 2001, but when more than 21/2 feet of touring car hauls past yc at above the legal speed limit, you don’t wish for more speed. The 3-speed gives the Big 6 improved acceleration and better low-speed handling by keeping the engine in the meatiest portion of its power band even at partial-throttle speeds. To hustle the machine around a tight course, we went for some drag brake and a kickit-out driving style. This is usually sketchy stuff with a 2WD car, but thanks to the Big 6’s size and heft, it was easy to control the amount of oversteer the chassis developed from turn to turn. The sensitive disc brake helped, too, with its superb feel. Be wary of fast stops at full speed, though; as a 2WD car, the Big 6 must rely on the rear wheels for braking, and it’s easy to overcome the limits of traction when you have to stop the car in a hurry.

INSIDE THE NITRO BIG 6

1. Oh, it’s big, all right. The Big 6 has a 3-inch-wheelbase advantage over the LandMax and Ultra GTP, but the car’s real sense of hugeness comes from its bathtub body and massive tires; at 4 inches in diameter, each is about as big around as a compact disc. Fully assembled, the Big 6 measures 26 inches bumper to bumper– that’s a lotta car-not a lot of weight, though. The Big 6 is actually lighter than the Ultra GTR

2. 4mm aluminum chassis. There’s a lot of chassis between the Big 6’s wheels, yet the car is a “single– deck” design. To give the chassis the rigidity it requires, Schumacher specs 4mm aluminum for the stamping, which includes a slight front kick-up. A separate plate constructed of Schumacher’s trademark Si composite is home to the fuel tanks and radio gear.

3. Two tanks. Most .21-powered cars include a 125cc tank, but the Big 6 carries i5occ in a pair Of 75cc tanks. It looks coo[, but it slows down pit stops, and the tanks’ small openings and tightly sprung lids don’t help to speed things up.

4. Three speeds. When we first reviewed the Nitro Big 6 (May 2001), it was equipped with a single-speed transmission. Now it has a 3-speed tranny-a clever setup that uses ratchets in the gears instead of one-way bearings. We’ll see how much that translates to a speed increase; even with one speed, the Nitro Big 6 topped 50mph when we last tested one!

5. Rear-wheel drive. Unlike the buggy-based OFNA and Kyosho machines, the Big 6 is a 2WD car. With less drive train to absorb the .21 engine’s power, the Big 6 has to have a rugged transmission. And it does-in the form of an enclosed belt-drive system; but if you’re thinking about the belts in your electric touring car, think again. The Big 6’s single drive belt is extra wide and wraps around a ball differential that is also heavy duty, thanks to 3mm balls (Schumacher actually uses these balls in all its cars, but big is big). Telescoping plastic universals connect the diff to the wheels; as you might expect, ball bearings are used throughout.

6. Laydown damping. The Big 6 is undeniably huge, yet its shocks are lifted directly from Schumacher’s 1/10– scale parts inventory. The well-proven dampers have two-piece pistons that can be set for more or less damping by selecting more or fewer open holes, and a piece of foam in the bottom-loaded sealed cartridge handles volume compensation. Tall standoffs on the suspension arms and low-profile S1-composite shock towers give the plastic-body shocks their laydown position and the specific geometry required for Big 6 duty.

Copyright Air Age Publishing Oct 2002

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