You can sense good suspension travel by the way the Hurricane wallows around corners. There are two coils at each corner and 18 inches of total travel, 9 upward and 9 for droop. The shocks are adjustable take-aparts, and the coils can be swapped out for stiffer or softer ones. Today the vehicle is, overall, very lightly sprung. "You'd never want to drive it on the street this soft," Quigley told us, "but for conforming to different land forms, it's pretty good." For the fun of it, Quigley walked the Hurricane over a few concrete parking space bumpers, absurdly small obstacles given the suspension.
There is enough travel for the tires to easily contact the upper fenders. So the Jeep engineers put the fenders on hinges. They flip up when the tire gets jammed into the wheelwell: "With this tire size, with the jounce travel we have, by the time we got the fenders where they'd clear, it was looking stupid. So the solution was to have the fenders move out of the way."
Just from the feel of it, we think the Hurricane would ramp 750, maybe 800 on a 20-degree ramp. "And because there is no axle and no center diff, the lower control arms go almost to the center of the car. So when I go to full jounce and rebound, this tire is almost straight up and down-most of the tread is still on the ground. And we can transfer all the power to that one tire. Even if the other three are in slop, that one tire has enough tread on the ground and it just digs,"said Quigley.
Tires are LT305/70R20 Goodyear MTR (Military Tread Revised). "They cut the pattern specially for us, but it's basically an MTR tire they're working on. It's a hell of a tire. We've only got maybe six of these. So if we screw 'em up, I've got two more," Quigley apologizes, "and that's it." Ground clearance is more than 14 inches, and approach and departure angles of 64 and 86 degrees, respectively, are well into Top Truck Challenge territory. The crawl ratio, we're told, is about 38:1.
The Hurricane may not have insane travel, but the steering is the sickest thing we've ever seen. It can steer normally, like a car, via a fixed rack-and-pinion at each end. Tied to each rack is a worm-gear setup with position sensors. Drive the worm gears, you hear an electric motor noise as it brings the tires outward, front and rear simultaneously, to create "skid steer." In skid steer, all four wheels point outward, but at opposite angles on each side, so the Hurricane can grind a turn in its own radius. In skid steer, there is so much tire scrub that the Hurricane left a baffling, perfectly round doughnut-shaped rubber burnout print on the tarmac. On pavement, skid steer tears up the tires. In mud, it would be pretty handy, kind of like a tractor rotating by reversing the treads.
Then the Hurricane's tires can be pointed 46 degrees inward, for "toe steer," allowing the vehicle to roll freely in its own radius. A demonstration of this mode, as Quigley feeds in power, is something like the whirl-a-gig ride at the country fair, leaving us just slightly disoriented.
Then there is 4-Steer, which is regular four-wheel steer like GM has used on pickup trucks, and Crab Steer, where the rears go with the fronts, instead of the other way. The advantage there would be to move sideways without changing direction. Considering the trail potential of the various modes left us completely in awe.
While there is no plan to offer the public anything like the Hurricane, there are some practical applications to the technology. Instead of two V-8s, imagine combining one gas or diesel powerplant and one electric motor-a hybrid Jeep. And flip-up fenders could be built by anyone.