Tamiya TGR

Tamiya is well known for designing innovative and true-to-scale RC vehicles, but lately, its engineering efforts have seemed to be focused more on the competitive end of the RC spectrum. As a result, Tamiya recently released several vehicles that not only look good, but they have the necessary ingredients for serious competition, too. The subject of this Track Test-the Tamiya TGR-happens to be one of them. One look at its low-slung, black-on-black chassis is all it takes to realize that this new, super-class entry is designed to do one thing: intimidate the competition. As an editor of Radio Control Car Action, however, I've learned never to judge a book by its cover, so off to the track I went. Does the Tamiya TGR have what it takes to be a predator in the growing super touring class? Let's find out. Chassis. The TGR's narrow, 2.Smm-thick duralumin chassis resembles the chassis plates that are used on 1/8-scale, .21-powered on-road vehicles. It places the weight of all the drive-train components and onboard electronics closer to the chassis centerline for improved handling. The screwholes are completely countersunk, so all the screws can be mounted flush with the chassis, and openings under the front and rear diff cases, the fuel tank, engine, swaybars and 2-speed allow these components to be mounted with the lowest possible center of gravity (CG).

The long and narrow, 2mm-thick graphite upper deck is mounted on the front and rear suspension assemblies and neatly houses the onboard electronics. Graphite is lighter and more rigid than aluminum and plastic, and that makes it a welcome addition to any racecar. A racing-style front bumper with a urethane body protector and a molded transponder mount are also on the list of hot features.

* Drive train. The TGR's shaft-drive system is similar to the drive train used on the TGX-Mk. 1, but the TGR has lighter, more compact diff cases and smaller, cast-alloy ring gears that allow the diffs to be mounted lower on the chassis. In addition, both the front and rear diffs-and the rest of the drive train-are offset 7mm to the right side of the chassis to allow the engine and fuel tank to be mounted as close as possible to the chassis centerline.

The cast-alloy internal bevel and spider gears inside the diffs have large teeth that look as though they should be able to handle plenty of horsepower. Tamiya supplies a thick grease to slow down the diff action, and it's so effective that I'm going to order more of it to use on my other gear-diff-equipped cars.

A single lightweight aluminum propeller shaft joins the two gearboxes and provides full-time 4WD. A newly designed, adjustable 2-speed transmission is attached to the rear gearbox and is joined to the front by the main propeller shaft. Instead of using a locking "fingers"-type centrifugal shifting system, which is common on many other 2-speed-equipped vehicles, Tamiya adopted an adjustable 2-shoe centrifugal clutch system to engage the shift point. The Tamiya 2-speed transmission shifts very smoothly and should require less maintenance than conventional 2-speed systems.

The TGR features the same disc brake system as is found on the TGX-Mk.1. Two cam-actuated steel brake pads pinch the 3mm-thick fiber-composite disc brake that's keyed to the 2-speed transmission's drive hub. Regardless of which servo you use, this braking system should provide smooth, controlled braking without fading. Front and rear steel dogbones and serrated axles with aluminum hex hubs complete the drive train (no more drive pins; way to go, Tamiya!). I was a little bummed that the TGR doesn't include universal axles for the front, but this is made up for by the fact that the entire drive train-including the wheels-spins on Tamiya's high-quality rubber-sealed bearings.

e Suspension. The TGR features an all-new racing suspension that includes extra-long front and rear lower suspension arms and unique molded, telescoping upper links. The lower suspension arms capture the front "C" carriers and rear hub carriers for added strength, and the entire suspension pivots smoothly on stainless-steel hinge pins. Setscrews threaded into the lower front and rear suspension arms allow down-stop travel adjustment. The two-piece molded upper links have corresponding male and female halves that are joined with threaded rods. The downside to this system is that you have to unfasten one end of the molded upper links to make camber adjustments, but the molded upper links are more rigid than standard camber links, and that makes up for the slight inconvenience.

Tamiya's excellent aluminum-body, oil-filled shocks with double O-ring seals, silicone diaphragms and Teflon pistons and shaft guides are standard issue. The shocks are black-anodized to match the rest of the car's components, and they provide exceptionally smooth performance. The front shocks snap onto ball joints that are installed on the suspension arms and front bulkhead. The rear shocks are also attached to the suspension arms with ball joints, but the upper portions are attached to a graphite shock tower. To provide more progressive damping, all four shocks are mounted in a laydown position, and stiff front and medium rear springs are included to balance out the car's handling. Also included are front and rear ball-and-cup swaybars that can be adjusted to reduce body roll and divert traction to the front or rear as necessary