May 2005 Cover of Offroad Adventures, "The Night Stalker"

Coined “The Stalker” for its stealth and agility, is a culmination of on-the-track experience and experimentation. Jake Hallenbeck, owner of Canyon Krawlers in Reno NV, visualized an out-of-box approach to this concept buggy.

Traveling around the country covering events is one of the benefits of working in the publishing side of off-roading. We not only get to check out some great trails and the axle-twisting action of competitive events, but also witness firsthand the latest and greatest in off-roading technology. When it comes to new drivetrain and suspension technology, the past four years have brought us more trick gizmos and doodads than we ever would have imagined. And, many of them can be purchased right off the shelf. We’ve brought you three-link, four-link, and quarter elliptic suspensions, fire breathing four-banners and air cooled VW mills, to big block V-8s and torque monster diesels, four seats, two seats and single seaters. We’ve seen rock buggies of every shape and configuration. Just about the time we start getting confident and think we have seen it all, someone like Jake Hallenbeck comes along and puts us in our rightfully humble place.

This was the case at the spring Cal-4-Wheel, 4WD & Off-Road Expo in Reno NV. While checking out the new technology and talent at the outdoor vehicle show, through the midway resonated the unmistakable whine of a semi-uncorked rotary mill. Gravitated toward the curious noise, we found a group huddled around what appeared to be a pint-sized sand rail on steroids. The foot laying down the skinny pedal was that of rock racing veteran Jake Hallenbeck.

Attaching the rear Toybox to the Stalker chassis is a four-link suspension. The upper links are centered and triangulated to the chassis while the lower links are mounted in an inverted position. The inverted lower links maximize ground clearance and act as rocksliders when clearing obstacles.

Sixty-two inches of front articulation is accomplished with a three-link system while a pan-hard rod manages axle placement. Dampening and levitation duties are managed by Bilstein 5100 shocks and coil springs at each corner.

The heart of the Stalker is a Mazda 13B Rotary turbo mill. At 170lbs, the 13B is said to generate a whooping 270 horsepower. With the exception of a K&N air filter, 2.5-inch aluminum exhaust system and Supertrap muffler, the 13B turbo was used without major modification.

Rotary mills have been providing high-performance reliability on the racetrack for years. They provide a high horsepower-to-weight ratio, can be tuned for lightening fast throttle response, and when appropriately built, will spin to higher RPM than any piston engine. As less weight and more ponies are always a priority, the high power-to-weight ratio of using a rotary beckoned consideration. It was only a matter of time before one ended up in a competition rock buggy.

This rotary rocket, coined “The Stalker” for its stealth and agility, is a culmination of on-the-track experience and experimentation. For the ’04 season, Hallenbeck, owner of Canyon Krawlers (CK) in Reno, NV, known for quality solid-axle conversions, desert trucks, and turnkey rock buggies, envisioned something different. For that something different, Jake began to visualize his next concept buggy with an out-of-box approach.

The heart of the Stalker is a Mazda 13B Rotary turbo mill. At only 170 lbs, the 13B generates an estimated 270 horsepower. Although rotary mills are not known for massive low-end torque, when combined with a turbo charger and appropriate drivetrain components, Jake says the rotary provides a wider speed range in a given gear. This is always a consideration for the heinous obstacles of rock racing courses. With the exception of a K&N air filter, 2.5-inch aluminum exhaust system and Supertrap muffler, the 13B turbo was used without major modification.

The attention to detail on this rig is without compromise. A polished aluminum fuel cell, matching rear deck and fire extinguishers, we like it.

A closer look at the front shows the merge point of the inverted Toyota V-6 a Unimog portal outer sections.

All vehicle controls are easily accessible from the cockpit of a neatly appointed aluminum interior. Kirkey racing seats and RJS four-point harnesses keep driver and co-pilot secure when the rubber side goes up.

Coupling a Suzuki Samurai transfercase, fitted with 4:16 to 1 reduction gears, is the OEM three-speed slushbox transmission (that’s an automatic for non-gearheads). To handle tight coursework required in competition, the rear driveline was fitted with a driveline disconnect. Because hard-core competition is hell on the underbelly, vital components are tucked neatly out of harm’s way. Since drivelines are always at risk of damage, Jake chose to run, find-em-anywhere, Toyota drivelines and joints. They are super tough, can be fabricated on-the-spot if needed, and there is usually a pile of them close by in someone’s backyard.

When it came to axle choice, high ground clearance, ultra-low gearing, and the ability to take a pounding were crucial. And, the Stalker merited something new and unique. The result was a hybrid combination of Toyota and Unimog, the CK Toybox. The Toybox began with an inverted Toyota V-6 housing, the third member fitted with an ARB locker and 4:10 ring and pinion gears. Sounds pretty basic, right? Now for you Toyota buffs, this is where it gets interesting. Jake’s team capped each end with a pair of Unimog portal gearboxes. The combination provides a final axle ratio of 8:34 to 1, provides ultimate ground clearance while keeping the center of gravity as low as possible, and keeps vital components far from tierra firma. It is rumored that the Toy box may be a production item in the near future.

Attaching the rear Toybox to a custom CK Stalker chassis is a four-link suspension. The upper links are centered and triangulated to the chassis while the lower links are mounted in an inverted position. The inverted lower links maximize ground clearance and act as a rockslider when clearing obstacles. For dampening and levitation, Bilstein 5100 shocks work in harmony with a pair of coil springs. Up front, the same inverted link theory was applied and a pan-hard rod manage axle placement. To ensure reliability under the brutal conditions of rock racing, all links are attached via 2.5” Rubicon Express joints and directional control is maintained via a Rock Equipment hydraulic steering setup.

To handle tight coursework required in competition, the rear driveline was fitted with a driveline disconnect.

To ensure reliability under the brutal conditions of rock racing, all suspension links are attached with 2.5” Rubicon Express joints while directional control is accomplished via a Rock Equipment hydraulic steering setup.

To maintain the balance between lightweight and super tough, the entire frame and suspension was fabricated out of 1.5-inch diameter .250 DOM tubing. Additionally, the forward mounted 6000k Warn winch is wrapped with lightweight Master Pull winch line. To enhance the low CG, the battery is neatly tucked under the passenger seat. Other trick stuff includes a line-lock system, Kirkey racing seats and RJS four point harnesses to keep driver and co-pilot secure during rollovers. Keeping this entire ensemble in close touch with tierra firma is a set of 37-inch BFGoodrich Krawlers wrapped around Walker Evans racing wheels.

With the paint barely dry, we caught up with Jake and the Canyon Krawler crew near Reno Nevada’s Moon Rocks area. Hallenbeck finessed the Stalker up some of the most insane obstacles we’ve seen. And, managed to keep the rubber side down. We’re looking forward to witnessing the stalker competing. Out of the box, new stuff, we love it.

Keeping the Stalker contact with tierra firma is a set of 37-inch BFGoodrich Krawlers wrapped around Walker Evans racing wheels.

Coupling a Suzuki Samurai transfercase is an OEM three-speed slushbox transmission. The transfercase was fitted with 4:16 to1 reduction gears.

The Stalker sports a new Canyon Krawlers hybrid axle, the Toybox. A combination of Toyota and Unimog components. The Toybox uses an inverted Toyota V-6 housing capped with a pair of Unimog portal gearboxes. Fitted with an ARB locker and 4:10 ring and pinion gears, the combination provides ultimate ground clearance, allows for a lower center of gravity, and a final axle ratio of 8:34 to 1.