In function, Quadrasteer's multiple sensors measure a truck's road speed and the steering angle of the front wheels, then an electronic control unit (ECU) determines the proper amount of steering angle for the rear wheels. Quadrasteer operates in three basic modes: negative, neutral, and positive. At low speeds, the Delphi Automotive Systems-designed Quadrasteer steers the rear wheels in the opposite direction of the front wheels - negative mode - to enhance low-speed maneuverability. At moderate speeds, the rear wheels are set to the straight-ahead, or neutral, position. At higher speeds, the rear wheels are phased in a positive mode, which causes the rear wheels to steer in the same direction as the front wheels, thus enhancing at-speed stability via a reduction in a truck's yaw, also known as lateral rotational motion or sway.
The General had previously released data on Quadrasteer's effect on a truck's turning radius: A fullsize, extended-cab truck's turning radius was reduced from 46.2 feet to 37.4 feet with the four-wheel steering system; when installed on a fullsize SUV, Quadrasteer reduced the turning radius from 45 feet to 33.9 feet. For comparison, a Honda Civic's turning radius is 32.8 feet. It's exciting to ponder Quadrasteer's on-dirt potential: Tight trails would become passable for fullsize haulers, and the rearend would actually steer around obstacles, ruts, and rocks situated at a corner's apex, thus making for improved traction and a better-handling 4x4 in overall terms.
The Dana Corporation has been tagged by the General to build the rear Quadrasteer axles, which will be the first time a production truck has used four-wheel steering.
Las Vegas Hosts Major Off-Road Show
Add one more event to your 2001 calendar: American Mega Shows' Las Vegas Sand and Off-Road Show, which takes place in you-know-where on the weekend of June 16 and 17. The Vegas location was chosen because of its status as the entertainment mecca, it's accessibility to five western states, and its indoor show facilities.
The show will be taking over the Las Vegas Cashman Center. At press time, the show was slated to feature more than 300 exhibitors and manufacturers of aftermarket off-road accessories. Show hours are from 10 a.m. to 5 p.m. both days, and admission is just $8. Important show note: Beer will be on sale throughout the weekend; and a live band will be featured to provide additional entertainment while you're viewing the latest off-road equipment, 4x4 show trucks, ATVs, sand buggies, and plenty more.
For more information, contact: American Mega Shows, (626) 961-3782, or visit the Web site at www.megashow.com.