1/8-SCALE ELECTRIC 4WD MONSTER TRUCK | RTR
PHOTOS BY JOEL NAVARRO
TTR's tough truggy gets treated to a heaping helping of horsepower
Today's 1/8-scale truck class got its start in the mid-2000s with conversion kits that crossed monster trucks with 1/8-scale buggies, and it didn't take long for manufacturers to catch on — Thunder Tiger was an early adopter of the new spec, and created the original ST-1 kit in time for the first ROAR Nationals in 2005. With big tires, long travel suspension, and the largest footprint of any mainstream racing class, these overgrown stadium-style trucks still produce the fastest lap times on rough tracks to this day, and while nitro still rules the roost in competitive circles, that versatility and stability makes them the perfect platform for brutal brushless power. Thunder Tiger's ST4 G3 is a prime example of when information learned on the track trickles down to the everyday hobbyist. With 14.8 volts of electrons now flowing through its veins rather than 30% nitro fuel, this version of the TT ST is a whole different animal.
Item no.: TT6404
Weight, as tested: 8.6 lb. (3920g)
Type: Double-deck plate
Material: Stamped 3mm aluminum
Type (F/R): Dual pivot ball / lower H-arm with upper camber link
Inboard camber link positions (F/R): 1/5
Outboard camber-link positions (F/R): NA/4
Shock positions, towers (F/R): 4/6
Shock positions, arms (F/R): 2/2
Bodies: Plastic 16mm bodies with ride height clips
Shafts: 3.5mm, plated finish
Volume compensation: Bladder
Type/ratio: 4WD with front, center, and rear differentials/4.3:1
Spur gear/pinion: 48/13
Slipper clutch: None
Differential: Sealed oil-filled
Driveshafts: Steel CV-style front and rear, steel center dogbones
WHEELS & TIRES
Wheels: Thunder Tiger black dish wheels, half-inch offset
Tires: Thunder Tiger square-lug, soft compound, open-cell foam
Body: Thunder Tiger ST4 G3 body, pre-screened
Transmitter: ACE RC Cougar GP3 2.4GHz 3 channel
Receiver: ACE RC TRS403ss 2.4GHz 4 channel
Speed control: ACE RC BLC-80C brushless LiPo speed control w/reverse
Motor: ACE RC Ripper IBL40 2000 KV brushless motor
Steering servo: ACE RC DS2008MG Digital Metal Gear, 130 oz.-in.
TEST GEAR (NOT INCLUDED)
Battery: TrakPower 6800mAh 2S 7.4V 70C LiPo battery × 2
HEAVY-DUTY TRIPLE-DIFF DRIVETRAIN
The center differential sitting below that red diff mount brace gets much of the credit for the ST4's off-road prowess.
Three oil-filled gear differentials are in charge of metering the power to the tires, though it's the unit in the center of the truck that's most responsible for the truck's off-road poise — the center differential was one of the biggest differences between old-school monster trucks and new-age 1/8-scale stadium trucks, which allows the front and rear diffs to temporarily spin at different speeds when traversing rough terrain in order to avoid upset ting the chassis. Steel CV-style universals are a welcome addition at the front and rear, though dogbones to key the front and rear gearboxes to the center differential are more than adequate as you won't likely lose one in the event you actually manage to break something.
PLUSH LONG-TRAVEL SUSPENSION
The ST4's long arms are thickly molded to handle fun-running abuse, and the pivot-ball hubs allow precise camber adjustment.
The shocks fall well into “big bore” territory with their 16mm inside diameter, and are stiffy sprung for big-hit action.
Though they're not threaded, and instead rely on clips for ride height adjustments, the plastic shocks on the ST4 are up-to-date with a large 16mm bore, and plastic caps at both ends to contain the bladder and O-rings. They can be mounted in a variety of locations on both stamped aluminum shock towers, which are abundantly burly at 3mm thick. Though the rear suspension gets a typical lower H-arm with a threaded upper link, the front upper arms and lower wishbones end in pillow balls that offer near-infinite camber and track width adjustments. Check out the shape of the upper front arms — if that's not enough of an indication of the abuse this truck was meant to endure, just look at the amount of material used for the rest of the truck!
DOUBLE-DECK PLATE CHASSIS
The upper deck is an interesting addition to a well-sorted chassis, providing extra stiffness and protection. Four easy-to-operate hinged locks make battery changes a snap.
The most interesting update to the ST4 G3 is its chassis design, which uses a stamped aluminum plate for a lower backbone on which to mount everything, and a removable plastic upper deck that's locked into place with four hinge locks. The main purpose of the upper deck is to retain the batteries, either two 2S LiPo batteries or a single 4S pack, but it also provides additional stiffness and rigidity for the chassis as well as extra protection for the running gear. Like the upper deck's locking tabs, the center diff mount brace and lower spur gear skidplate, which protrudes below the aluminum plate, are molded in red plastic.
Do those large adjustment dials and comfortable grip look familiar? The ACE RC Cougar GP3 transmitter is the same unit used in Team Associated's Rival monster truck — it worked well then, and it does so now.
BEHIND THE WHEEL
The tires included with the ST4 G3 are older 1/8-scale truck-style, with tall sidewalls that emphasize the truck's rut-bouncing behavior as they tear the dirt beneath them when you clamp the trigger. The first time I jumped on the throttle, the urgency with which the G3 raced to its top speed caught me off guard — I was not expecting this truck to have that much power! I have no doubt that taller gearing would extend the truck's 35mph top speed, but that's plenty fast to be a bit scary when the nearly 9-pound G3 is skipping across ruts and blasting berms. If it wasn't for the center differential, the truck would likely front-flip when the trigger is flicked forward, but that same power-transferring marvel of modern engineering makes the truck surprisingly stable over rough terrain — almost too stable, as the truck rewards bone-headed, ham-fisted driving with more speed, more roost, and more fun. The servo isn't remarkably fast, but I never noticed — it did a great job manhandling the big front tires in whichever direction I chose and no matter how hard I tried to pitch it sideways the truck simply followed suit …which, of course, meant that I kept trying harder. I never managed to get the truck stuck anywhere, but reverse sure came in handy during the photo shoot!
Being able to transfer all that power to the ground, regardless of how rough the ground is beneath it, makes it easy to gain plenty of speed leading up to the face of a jump and launch the surprisingly agile monster skyward. The instant reaction of the speed control to throttle and brake inputs mid-air made it easy to adjust the truck's in-flight attitude, and the combination of cushy tires and well-sorted shocks soaked up even the most extreme jump landings — even after soaring well overhead. In fact, the ST4 was the first truck I've tested that could repeatedly double-double its way through our SoCal test track's tricky rhythm section, yet didn't mind blitzing the bumps full throttle as well. When the truck unexpectedly rolled to a stop I thought I had finally won the battle — but it turns out that the motor had simply moved away from the spur gear, which required a ball-end 2.5mm wrench and some creative maneuvering to tighten back in place. Then it was back to an afternoon of trying to beat the truck into submission, but I wore out before the ST4 G3 did.
HIGH-POWER RUNNING GEAR
What the motor and speed control lack in flashy graphics, they make up for with power and pack a serious punch.
The body for the ST4 G3 loosely resembles a truck and is screened in red and black, with fluorescent yellow accents added later as stickers rather than painted into the scheme. Beneath it, you'll find the 4-channel receiver fastened straight to the chassis — no receiver box here — opposite a digital metal gear servo rated at 108.3 oz.-in. of torque and .21 sec./60 deg. Since the receiver is left open to the elements, it's a bit of a waste that the 80A speed control has a waterproof and dustproof case with integrated fan, but the high-power unit is charged with controlling the power sent to the 1/8-scale sized, 40mm long IBL 40/20 motor rated at 2000KV. That motor spins soft-compound tires with an aggressive square-lug pattern, which are mounted to black dish wheels that match the large rear wing.
Soaks up radical terrain
Withstands a serious beating!
Not a fan of the extreme cab-forward styling
Electronics are exposed to water and dirt
With the Thunder Tiger ST4 G3 clearly designed for high-output fun rather than competition aspirations, I find the best judge of its performance to be the grin pinned across my face and accompanying giggle that didn't stop until the truck did — thank goodness for the LiPo cutoff! The ST4's incredible off-road prowess calls for prodigious power, and the included electronics are totally up to snuff, though they're not protected from the elements. Since the truck isn't pre-destined for the racetrack I'd much prefer the truck look more like, well, a conventional truck, but the ST4 G3 is a terrific example of both what happens when good race trucks transition to the sport-driving scene, and that beauty is more than Lexan deep.