Project Tamiya Terra Crusher

Radio Control Car Action, Jan 2003 by Hetmanski, Kevin

Although I was tempted to whittle a few aluminum parts for my plus-size Tamiya Terra Crusher (TC) as soon as the big rig became available, I sat tight to see what the aftermarket would cook up. The wait was worth it; New Era, Golden Horizons, Megatech and Tamiya (of course) now offer a bunch of dress-up and durability-- enhancing parts that I put to good use in Project Terra Crusher. Penguin R/C helped out, too, with a bit of custom graphite goodness (you'll see). Bigblock power is the finishing touch-and vital, considering all the hefty aluminum parts I bolted on!

Parts list

GOLDEN HORIZONS

Bulkhead bracket-item no. GH02703B; $19.99

Aluminum C hub set-GH02708S; $39.99

Knuckle arms-GH02707B; $49.99

Bulkhead support-GH02709S; $14.99

NEW ERA

Silver super duty bulkhead (F/R)-TEC330-31; $85

Bumpers and supports (F/R)-TEC322Z/TEC323Z; $39.95 each

Forward-only conversion-TEC348; $29.95

.21 conversion kit-TEC110; $139.95

Aluminum gearbox support clamp-TEC360; $18.95

Lower braces-TEC326; $59.50

Center skidplate-TEC334; $14.95

FUTABA

9250 digital servo-S9250; $106.99

9450 digital servo-S9450; $121.99

TAMIYA

Aluminum hex hubs-53496; $15.99

Shocks TXF-1 Super-low-friction damper set-53492; $44

TRINITY

Terra Crusher spring set-TK5131; $11.99

Monster Horsepower 20% nitro fuel-MH020M; $29.99

650mAh AAA receiver pack-RC5308; $29.99

RPM

Associated GT receiver box (blue)-70055; $9.95

OMEGA

.21 sport buggy pull-start engine-OMAP200; $179.99

MEGATECH

Titanium kingpin set-MTC24801; $22.50

Aluminum steering with bellcranks-23814, $48

Body-post set-23829, $67

Carbon brake disc-24813, $20

Performance

I almost didn't want to drive my Terra Crusher after I had built it; it looks too good to run through dirt, but you have to do what you have to do. After breaking in the engine, I tweaked the carb needles for maximum performance. The Omega 21 engine really brought the Terra Crusher to life!

The smaller tires increased the final gear ratio and caused the top speed to suffer slightly, but acceleration is unbelievable; this truck really rips. Just the slightest tap of the throttle, and the truck lights up the wheels and takes off, throwing dirt everywhere. First gear winds out very quickly, and once the truck hits second, it isn't long before it hits top speed. I should definitely gear up the tranny a bit; the chassis is slotted, and New Era offers a couple of gears, so that shouldn't be a problem.

The truck's revamped suspension soaks up the bumps very well, and jumping the Terra Crusher is a dream. The Trinity springs were a good addition; they don't have any trouble supporting the heavy .21 engine and the many aluminum hopups. Thanks to the Futaba servo and smaller tires, steering has been improved.

Despite the truck's considerable heft, it's actually very responsive and has a "light" feel at the wheel.

CHASSIS. I started with New Era's .21 conversion kit, which includes a new, 3.2mm aluminum chassis plate (thicker than stock). The chassis has the same stock wheelbase and will accommodate a big .21 engine without a problem (see the "Engine and accessories" section for more on what the .21 conversion kit includes).

I wanted to clean up my truck's looks a little, so I ditched the stock "shovel-head" radio box/forward chassis assembly in favor of a single graphite plate that I designed using CAD. I sent the design as a computer file to the guys at Penguin R/C, and they cut the part out of 3mm graphite. Looks good, eh?

I positioned the throttle/brake servo so that it's next to the engine, and I replaced the stock,'1/4-scale steering servo with a high-torque servo of standard size that's installed in pretty much the same position as the stock servo.

The chassis is supported underneath by New Era's aluminum lower chassis braces. They are machined out of solid aluminum billet and include all the necessary mounting hardware. A super-duty, 3.2mm-thick, aluminum center skidplate from New Era protects the bottom of the transmission.

I enhanced the truck's looks with front and rear aluminum bumpers and supports from New Era.

SUSPENSION. New Era's super-strong aluminum bulkheads grace the front and rear. Machined out of solid aluminum billet, these three-piece units consist of left and right bulkheads and a shock tower (this offers seven shock-mounting positions for each shock). Golden Horizons blue-anodized aluminum bulkhead braces join the left and right bulkheads.

I replaced the stock plastic suspension arms with a Golden Horizons blue-anodized aluminum set that is beautifully machined and super strong. Aluminum hub carriers, also from Golden Horizons, join the upper and lower arms; the axles are housed in Golden Horizons machined-aluminum hubs. I ditched the stock shocks for Tamiya's high-quality aluminum units. They're machined to the tightest tolerances and have a silky smooth action. I used a set of extra-stiff blue Trinity springs to support the chassis' considerable weight.

ENGINE AND ACCESSORIES. New Era's .21 conversion kit includes a new chassis plate, engine mounts, a new clutch nut, a flywheel, a linkage assembly and a forward bearing for the clutch bell. I bolted the parts to an Omega pull-start .21 that features a heavy-duty starter, an ABC piston and sleeve, a 2-needle composite slide carb and an SG crank-a full race setup.