Tamiya TB Evolution III Surikarn Limited

Radio Control Car Action, Oct 2003 by Vieira, Peter

1/10-SCALE ELECTRIC

Tamiya TB Evolution III Surikarn Limited

THAI FIGHTER

NO DRIVER IN RC HISTORY has gone from obscurity to world champion as quickly as Thailand's Surikarn Chaidajsuriya did with his victory at the 2002 IFMAR World Cup. Surikarn wheeled Tamiya's dual-belt TRF 414M to earn that win, but he has since graduated to shaft drive with the TB Evolution III. The car has been a great success for Tamiya, with a win at the German Indoor Cup in the hands of Marc Rheinard and the Japanese Yama Yama Cup courtesy of Satoshi Maezumi. But it is Surikarn's most recent victory that has Tamiya revisiting the TB Evolution III. To commemorate Surikarn's stock and modified victories at the 2003 Thailand International Touring Car Championships, Tamiya has given him the honor of a signature car: the Surikarn Limited. The full-option ride is as showy as racecars get, but it also reflects the personal performance mods that Surikarn made to get his Evo III into the winners' circle. It's the ultimate shaft-drive Tamiya touring car!

SPECIFICATIONS

MANUFACTURER Tamiya

MODEL TB Evolution III Surikarn Limited

SCALE 1/10

PRICE $450 (Varies with dealer)

DIMENSIONS

Wheelbase 10 to 10.4 in. (255 to 265mm)

Width 7.3 to 7.4 in. (186 to 189mm)

WEIGHT

Total, as tested 52 oz. (1,498g)

CHASSIS

Type Double-deck plate

Material 3mm graphite main chassis, 2.5mm upper plate

DRIVE TRAIN

Type 4WD shaft

Primary 34T pinion/96T spur gear

Transmission ratio 2.6:1

Final drive ratio 7.34:1

Drive shafts CV-type (F/R) steel/aluminum

Differentials (F/R) one-way unit/ball differential

Bearing type Rubber-sealed ball bearings

SUSPENSION

Type Lower H-arm with turnbuckle upper link

Shocks Aluminum threaded-body, fluorine coated

WHEELS

Type Tamiya dish, zero offset

TIRES

Type Sorex 36R with urethane insert

KIT FEATURES

CHASSIS. A graphite-plate chassis is hardly a surprise on a pro-caliber kit, but the TB Evolution III Surikarn Limited (or Evo SL, for short) beefs up the chassis to a full 3mm; the standard Evo HI and most other tourers with plate chassis use 2.5mm stock. Six battery slots are milled into the chassis and a graphite strap is supplied to hold the cells, but it's set up for a stick pack (as required by the racing regs of Japan's sanctioning body), so the strap sits too high to hold individual cells. It's easy to mod the parts for a "side-by-side" pack-check out the "Building & Setup Tips."

The chassis' upper deck is 2.5mm graphite and sandwiches the front and rear gearboxes as well as the steering-bellcrank pivots and a machined-aluminum motor plate. Rest assured, it's a stiff setup. And here's the really cool part: titanium screws are used throughout. Very nice.

DRIVE TRAIN. Shaft drive is the hallmark of Tamiya's TB series, and the Evo SL has the most refined and heavy-duty system yet. The center shaft is solid aluminum, and it spins a rear ball differential and a front one-way unit. The one-way bearings are pressed into an aluminum hub assembly that the plastic ring gear is bolted onto. To prevent the ring gear from flexing when the one-way bearings dig in, it's backed by a graphite plate. The spur gear gets the same treatment, and it's braced by a graphite plate that squeezes it against an aluminum spur-gear hub. The rear ball differential breaks the "heavy-duty" theme and goes for weight savings instead with Delrin outdrives. Snap-on reinforcement rings prevent the outdrives from spreading under load, and the diff rings are keyed so they won't slip on the slick Delrin.

CV-style drive shafts are used front and rear, but they aren't identical. The front shafts are hardened steel to resist twisting when the one-way bearings grab, and the rears are lightweight aluminum and anodized red to match the Evo SL's other crimson components. Aluminum clamping drive hexes cap the axles, and rubber-sealed bearings support all of the rotating parts.

SUSPENSION AND STEERING. The Evo SL uses the same molded-graphite-composite arms as the standard Evo III, but it combines them with titanium turnbuckles instead of steel parts. The arms' hinge pins are held by machined-aluminum brackets, and four brackets are included so you can set the rear toe-in to zero, 2.5, 3, or 3.5 degrees. Precision aluminum spacers on the hinge pins allow up to 12mm of wheelbase adjustment, and the arms use droop screws to set down-travel. Front and rear swaybars are also standard. The manual calls for yellow "medium" bars as the starting setup, and "soft" (red) and "hard" (blue) swaybars are also included.

New aluminum bulkheads that wrap around the front and rear gearboxes are unique to the Evo SL. The bulkheads are threaded to hold the inboard ball studs vertical, and that makes it easy to make roll-center adjustments by stacking spacers under the studs.

The shocks are the centerpiece of any suspension system, and the Evo SL gets Tamiya's best. The aluminum shock bodies are threaded for precise preload adjustment, and the pistons, seal spacers and shaft guides are made of fluorinated plastic to reduce friction. The shock bodies and shafts also get a slippery fluorine coating that gives the shocks exceptionally slick action. The fluid included to fill the shocks isn't quite as special: it's Tamiya's usual, yellow, "soft" fluid. Graphite shock towers are standard (just as they are on the standard Evo III), but the SL's towers have new shock locations placed to Surikarn's specifications.