Kyosho TR-15 Rally Subaru Impreza

Radio Control Car Action, Sep 2003 by Machado, Elvis

IF YOU'VE EVER WATCHED A WORLD RALLY EVENT, YOU ALREADY KNOW that the all-wheel-drive, turbocharged-to-the-hilt cars with their electronically controlled sequential transmissions and active differentials are serious beasts that mean business. These cars and their pilots must navigate terrain that would rip apart a normal street car, and they do it at very high speeds, generally while sliding sideways and avoiding silly things like trees and the edges of cliffs. Companies such as Subaru, Peugeot, Ford and Citroen spend millions of dollars not only to finish a rally but also to win.

Since we can't all quite afford to drive $1 million rally cars, Kyosho decided to bring us this new TR-15 Rally Subaru Impreza in its "bigger than 1/10 scale" SuperTen size. While it may not sport a turbo or much in the way of electronic drive-train management, it is more than 19 inches long and packs a .15 nitro engine and full-time 4WD, so the TR-15 should prove to be a beast in its own right. Let's take a closer look to see whether it has what it takes to run the ragged edge.

Kyosho's GS15R engine is a reliable runner and well suited to the TR-15 chassis in its new rally role. The shorty head didn't raise any cooling concerns, but bigger would be better.

All the screws are countersunk, of course, and cutouts help the diff housings, pull-starter, flywheel and spur gear sit low in the chassis.

KIT FEATURES

CHASSIS. If the TR-15 Rally chassis looks familiar to you, it's probably because it was first used on the Inferno TR-15, which is a good thing, considering that the little Inferno is one tough off-road buggy. The Rally chassis is made of 2.5mm-thick aluminum plate with radiused edges to add stiffness. Since it has no upper deck, the servos are mounted directly on the chassis. Additional bracing in the rear comes from a rod attached from the rear bulkhead to the center spur-gear mount. In the front, molded braces attach the front bulkhead to the steering bellcranks. All in all, it makes for a stiff and strong setup with just enough flex to soak up the big hits without bending something. A large receiver box has plenty of room for your battery and receiver. Down below, you'll notice that all but the three motor and two servo screws are countersunk, and there are cutouts for the differential cases. The openings let the diffs sit much lower in the chassis, allowing a lower center of gravity and improving handling. Nice touch.

SUSPENSION AND STEERING. Kyosho also raids the parts bins for the suspension arms from the F-Ten line of cars. Up front, the burly lower A-arms are attached directly to the chassis with steel pivot balls. Up top are also A-arms, but these are constructed of two threaded steel rods and molded eyelets, which can be used to independently adjust camber and caster. The front hubs are sandwiched between the upper and lower arms and turn on large-diameter pivot balls of their own making a very smooth front end.

In the rear, equally robust plastic lower A-arms are held on the chassis using-you guessed it-more pivot balls. The upper arms aren't quite as fancy as the fronts and use a conventional adjustable camber link made of thick aluminum. Kyosho also skipped the pivot balls for the rear hubs; they are simply held together by the upper link screw and a hinge pin through the lower arm.

The shocks are mounted in a laydown position. They're short, plastic-body units topped off with gold caps that match the engine's cylinder head nicely. Inside, you'll find a one-piece shock shaft and piston (basically a nail with a big head), that, when teamed up with the included oil and stiff coil springs, makes a shock with smooth travel and heavy damping. The TR-15 is a big car, and the stiff suspension should enhance its on-road handling while it helps to prevent the chassis from bottoming. Snap-on preload adjusters set the ride height.

Dual bellcranks handle the steering with a big, built-in, fixed servo-saver; this baby should keep your servo very safe. Adjustable tie rods mounted on ball ends turn the front wheels, and a simple wire rod with a Z-bend attaches the servo to the bellcranks.

DRIVE TRAIN. Kyosho builds most of the drive train for you. The matching front and rear diffs are taken directly from the SuperTen and QRC lineup. The ring and pinion as well as the internal bevel gears are all made of cast metal and look as though they can handle a fair amount of punishment. To avoid aggravation down the road, the diff cases have holes to let you reach a loose outdrive grub screw without having to disassemble a bulkhead-a very welcome feature. Attached to those steel outdrives are beefy dogbones that send the power to the wheels via press-fit hex drives; make sure you give the wheel nuts an extra crank so they don't come loose.

The TR-15 has no center differential, and that's good; this setup makes certain that at least two wheels are always being driven ( unlike a 3-diff setup that can send all its power to an unloaded wheel). A small bulkhead houses a plastic, 39-tooth spur gear and a single, high-fiber, plastic disc brake with a steel caliper. The spur transfers power to the diffs through more steel outdrives and dogbones. Considering the dusty, dirty nature of a nitro on-/off-road car, it would have been nice to see some bearings in the drive train instead of bushings, but at least they are metal bushings and not plastic.