ROLLING THUNDER American Thunder: An Off-Road Revolution A thunderstorm is brewing in off-road racing. Chevrolet has joined forces with Mobil Oil Corp. and BFGoodrich to create a powerful new truck racing team which will compete in the HDRA/SCORE off-road series. The new American Thunder team consists of Vector Promotions' innovative Class 2 (unlimited two-seat vehicle) S-10 pickup and Nelson & Nelson Racing's powerful Class 8 (full-size twowheel-drive utility vehicle) Chevy Sportside. This pair of red-white-and-blue Chevrolets is aiming for overall wins in the demanding HDRA/SCORE series. Two of off-road's finest drivers will wheel the American Thunder machines through the treacherous terrain. Reigning Class 7 champion Larry Ragland will pilot Vector Promotions' trend-setting S-10. Frank "Scoop" Vessels, the Class 8 titlist in the 1988 Baja 1000, will drive the Nelson & Nelson full-size Chevy. The American Thunder team is a product of Chevrolet's growing involvement in off-road racing. "Starting out on the grassroots level and working our way up through the ranks, we came to realize that success comes best by putting it all together," said Jack McKenna of Chevrolet Marketing Special Projects at the team's first press conference. "Chevrolet wanted to
A lightweight composite body will cloak Vector Promotions' innovative Class 2 S-10 offroad racing truck. This American Thunder entry will be a top contender for an overall win in 1989.
be involved in a premier racing series to prove the durability of Chevrolet products," McKenna added. "The trucks race over mountains, along sandy beaches, through winding forests, across silty lakebeds, and over rough, rocky dirt roads. It's Mother Nature's own proving ground." Off-road competition showcases the toughness and performance of Chevrolet trucks, which account for half of the Division's sales. "The HDRA/SCORE series is our opportunity to demonstrate the capability and durability of Chevrolet products in head-tohead competition," says Chevrolet Special Products engineer Terry Laise. "While the American Thunder race vehicles are highly modified, their performance will reflect the capability of our trucks, their engineering design, and the abilities of the race teams." Chevrolet's alliance with Mobil and BFGoodrich marks the beginning of a new era in marketing for off-road competition. "By pooling their resources, the three major
sponsors of the American Thunder team will deliver a uniform, consistent message to enthusiasts who are interested in performance vehicles and racing," notes BFGoodrich representative Dick Edwards. The goal of the American Thunder team is to score overall wins in the 1989 HDRA/SCORE series. Vector Promotions' advanced Class 2 Chevrolet S-10 pickup has been designed to overthrow the classic dune buggy design,
which has ruled the realm of off-road racing since the early days of the sport. "The major thrust of the Vector Promotions program is to show that a truck is capable of taking an overall win in off-road competition," says Laise. "The objective is to construct a truck that is as close as possible to the ideal configuration for off-road racing. "The Class 2 S-10 will incorporate four-wheel independent suspension,
Driver Larry Ragland will share the passenger compartment with an all-aluminum 5.0-liter Chevy V6 in the American Thunder S-10. The computer-tested frame is fabricated from steel tubing.
long wheel travel, and optimized weight distribution," he notes. "Most important of all, it will retain the outward appearance of a truck. It has a front-mounted engine and rear-wheel drive. We believe that we can achieve the goal of an overall win with a production-based vehicle." Team manager Clive Smith and his crew of talented fabricators converted designer Bryan Kudela's blueprints into steel and aluminum at Vector Promotions' well-equipped shop in Orange, California. Smith plans to beat the buggies with an ultralight two-wheel-drive S-10 powered by a fuel-injected 5.0-liter Chevrolet 90-degree V6. This engine is based on the 4.3-liter V6s installed in production S-lOs. "The Class 2 rules are basically free, except for mandatory safety equipment," Smith notes. "As far as the vehicle's appearance, construction, and drivetrain, you can do whatever you like. Our target is 2500 pounds and 450 horsepower. We intend to build the fastest
vehicle in the desert!" This high-tech S-10 will have a 127-inch wheelbase, with 45/55 percent front-to-rear weight distribution. The all-aluminum Chevy V6 is mounted between the driver and passenger, while the S-10's automatic transmission is positioned close to the rear axle to distribute the drivetrain weight evenly. The lightweight composite S-10 body has been subtly stretched and recontoured to conceal the unique chassis. According to driver Larry Ragland, the American Thunder S-10 will have several advantages over its dune buggy rivals. "The first advantage is our truck's advanced engineering—there is simply nothing comparable in a buggy," Ragland explains. "We'll have a better power-to-weight ratio, and superior weight distribution on all four wheels. Our truck will have better brakes than a buggy, and a more reliable engine. I think we're going to surprise a lot of people this season!" The Vector Promotions Class 2 S-10 represents a
A balsa wood replica of the American Thunder S-10's frame was built from designer Bryan Kudela's blueprints to test chassis stiffness.
bold move forward for Chevrolet in off-road competition. "Vector Promotions' American Thunder S-10 has given us the opportunity to bring new technology to off-road trucks," says Laise. "It's an evolutionary step forward for the entire sport." The other half of the American Thunder team, the Nelson & Nelson Racing Class 8 Chevrolet Sportside, is also a strong contender for an overall win. This full-size C-series pickup is off-road racing's equivalent of an outlaw sprint car—fast, powerful, and intimidating. Driver Frank "Scoop" Vessels and owner/builder Jon Nelson blaze through the badlands at 140 mph with a specially modified 431cubic-inch, 630hp Chevrolet small-block V8. The Nelson & Nelson two-wheel-drive Chevrolet has more than a superficial resemblance to its production counterparts. The Class 8 rules require a stock frame, a production-type suspension system, and a steel cab. "We are allowed to fabricate components, but we have to retain the factory's original suspension design," explains Nelson. "Class 8 competitors are allowed to update their equipment by 'mismatching' the body and frame," Nelson continues. "We've taken advantage of this provision by using a torsion bar front suspension and coil spring rear suspension." Nelson's chassis innovations include a pair of air jacks, which speed up tire changes and vehicle repairs. "The pneumatic cylinders are similar to the jacks used on Chevrolet Indy cars," he reports. "They can lift one side of the truck in seconds."
Shaver Specialties Racing Engines in Torrance, California, assembled the team's arsenal of smallblock V8s. Ron Shaver applied the engine technology gleaned from years of experience with largedisplacement sprint car motors to his off-road engine development program. The cast-iron block's cavernous cylinders measure 4.145 inches in diameter. Shaver's technicians add a 4.00inch-stroke heavy-duty Chevrolet crankshaft to achieve a final displacement of 431 cubic inches. A pair of Chevy's latest aluminum Bow Tie cylinder heads, a Bow Tie intake manifold, and a single four-barrel carburetor satisfy this big smallblock's ample appetite for fuel and air. A dry sump oil system circulates Mobil 1 synthetic lubricant. A Turbo-Hydramatic 400 automatic transmission prepared by Art Carr backs up this potent powerplant. "An automatic offers better driveability than a manual gearbox," Nelson reveals. "It's more comfortable for the driver, and it puts the power down evenly. The result is better traction and less abuse on the drivetrain." "We have a proven combination at the start of the new racing season," says Nelson. "We spent 1988 working out the bugs. Running 'Old Faithful' should give us an advantage over the competition in the first part of the year. "Scoop Vessels is an outstanding driver. Between his ability and what we can put underneath him, I think we can bring home the championship!" The storm warnings are already flying in the desert. American Thunder is on the way!