SCORE Journal - The Official Publication of SCORE Off-Road Racing
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THE UNLIMITED CLASS EVOLUTION Vehicles That Shaped SCORE Off-Road Racing By Dan Sanchez In off-road racing, getting any advantage by means of a starting position, a more experienced driver, or a vehicle with more horsepower or suspension travel doesn't necessarily guarantee a win. This was obvious in SCORE's early history, where the term "unlimited" in a class allowed for a variety of specialty vehicles to be built. While some had much more horsepower than their competitors and early innovations such as four-wheel drive, most of those first unlimited vehicles broke more often than they won races. These vehicles, however, would spawn ideas, concepts, and innovations that led to the modern SCORE Trophy Truck and Class 1 vehicles that are engineering works of art. SCORE's history is riddled with specialty unlimited vehicles. Some were strange but awe-inspiring and are as much a part of SCORE's history as the people and places that made SCORE what it is today. "At the beginning, the only thing off-road vehicles had was what was brought in from other forms of motorsports," said Sal Fish, former SCORE owner and president. "Unlimited vehicles have changed over the years and have increased in speed and capability to levels I would have never imagined. At the start of SCORE, I was dealing with rules and regulations, but Mickey was always the innovator. I think it's important for the new generation of SCORE fans and racers to know what unlimited vehicles were and where they came from. Innovators such as Mickey Thompson, Walker Evans, Bill Stroppe, Parnelli Jones, the Herbst and McMillin families, Cal Wells, BFGoodrich Tires, and many others, had the ability to take the vehicles to the next level. It's a tribute to the racers themselves for what they've accomplished and it's something to be proud of." The evolution of the top race vehicles in SCORE had a humble start, but it jumped forward by leaps and bounds compared to any other type of motorsport racing. Here are some of the top vehicles that we feel have made an impact on the sport. THE MEYERS MANX Baja racing began with motorcycles, and it caught on quickly, with many prominent riders wanting to make a name for themselves by taking on the challenge. At the first professionally sanctioned race, the Mexican 1000 Rally in 1967, Bruce Meyers thought his lightweight dune buggy with a VW engine, chassis, and suspension could be faster in the Baja desert. He was right, and the Production Class designation of the combination created what is arguably one of the first "unlimited" vehicles in off-road racing history. The engine was a 1.2L four-cylinder with a four-speed manual transaxle and a single tube header exhaust. It used a factory VW swing axle suspension at the rear, with front trailing arms and torsion bars. Driven by Vic Wilson and Ted Mangles, the Meyers Manx made history by beating the time set by Bud Ekins on a Honda Motorcycle back in 1962 and recording the run from Tijuana to LaPaz in 27:38. BAJA BOOT The first purpose-built Baja off-road race vehicle, the Baja Boot, was the vision of GM Research and Development Engineer Vic Hickey. Using his experience in off-road military engineering, he came up with the Boot in just 30 days. At the 1967 Mexican 1000, the Baja Boot reached speeds of 140 mph with Al Knapp and Drino Miller in the seats. A broken rear strut took the vehicle out of that race, but at the 1969 Mexican 500, the Baja Boot won overall with Bud Ekins and Guy Jones in Category 4. The Baja Boot was ahead of its time and was the first Baja race vehicle built with a complete tube chassis and a 450 HP 350 CID V8 engine that sat in the rear for better balance and weight distribution. The Boot had nine inches of wheel travel and weighed 3,450 lbs. incorporating a GM TH400 automatic trans, Corvette rear drive assembly, Olds Toronado axle shafts, and a Dana transfer case. Its all-wheel-drive system could be disengaged to front-wheel drive when needed. THE BRONCO RIDES IN In 1968, more racers and vehicle builders wanted in on the massive publicity attained by having the fastest run at the Mexican 1000. Witnessing what the Baja Boot could do with all-wheel drive, race vehicle builder Bill Stroppe took notice. Stroppe also managed Ford's West Coast Racing Operations, and when Ford introduced the Ford Bronco in 1965 with four-wheel drive, Stroppe made some changes and entered the 1968 Mexican 1000. He upgraded the factory suspension, added a safety cage, and tried to widen the track width with larger tires. Stroppe had Larry Minor and Jack Bayer drive it in the race under the Production Class, ultimately earning the Overall win with the fastest time from Ensenada to LaPaz in 21:11:32. Equipped with a 302 V8 engine, the Bronco had a roll-bar, eight-inch wide wheels, modified fender flares, and a heavy-duty suspension that featured updated rear springs that gave it 11.5 inches of ground clearance. In subsequent Baja races, Rod Hall and Larry Minor would come over to Stroppe's race camp and take the Bronco to an Overall victory at the 1969 Mexican 1000 race, naming Stroppe Bronco and Larry Minor the first vehicle/racer to win the Mexican 1000 back-to-back. REVENGE OF THE BUGGIES Although the trend by factory-backed teams was to build custom vehicles designed explicitly for Baja racing, they also came with a high price tag. Most Baja racers looked towards new buggy chassis from manufacturers that emerged from racers wanting something affordable, light, and reliable. In the 1970s, builders saw the need to create full-caged chassis that could be made on an assembly line, and racers could outfit them with widely available and inexpensive VW engine and suspension components. Some of the more successful buggies in SCORE history came from Lynn Chenowth, with various vehicles branded with his last name, and Gill George, who created the line of Funco buggies with great success in Baja in the Production Classes. Legendary SCORE champions such as Bobby Ferro and the team of Malcolm Smith with Bud Feldkamp drove Funco Sandmasters to multiple Baja wins. Chenowth vehicles were also winning and making legendary champions from drivers such as Rick Mears, Ivan "Ironman" Stewart, Frank and his son Ryan Arciero, Mark Stahl, Doug Fortin Jr, Bob Gordon, Scott and Mark McMillin, and many others. Although these were technically production vehicles, they were unlimited in what could be added to the chassis. Buggies like the Chenowth Wedge had a VW rear independent suspension with a VW front torsion suspension. This gave the buggy nine inches of wheel travel. The Wedge allowed the driver to sit more upright for better visibility and would fit a VW 1600 engine, have mounts for dual rear shocks, and have an air-foiled aluminum roof. Lynn Chenowth recalled some racers saying the Wedge was proof that you didn't need a four-wheel drive to conquer sand, ruts, and other obstacles in Baja. The Funco Sandmaster SS1 and SS2 buggies were mass-produced vehicles that could easily be outfitted with the team's choice of VW components. Many teams used factory VW I-Beam front suspension, trailing arms, and 2180 cc VW engines with a VW transaxle. While the Sandmaster vehicles had the occupants nearly lying down in the chassis, they were light and strong. Many were seen flipping over during SCORE races in Riverside and Baja, only to be pushed over onto their wheels and be back running in the action. BIG OLY Bill Stroppe continued to develop the Ford Bronco platform, and with influence from Indy Racer Parnelli Jones, Stroppe and fabricator Dick Russel took the vehicle to a new level. They built a full-race version of the factory vehicle with a full tube chassis that was three inches narrower than the factory Bronco. It also used fiberglass body panels and a new Ford twin I-Beam front suspension with a four-link rear. This Bronco was built to be specialized for off-road racing and was called Big Oly from its Olympia Beer sponsorship. Big Oly was placed in the Two Seat class for modified or non-production vehicles. It proved that more horsepower in a custom chassis and suspension could be a dominant factor in Baja racing. Big Oly had a full floating Ford 9-inch rear with 4:11 gears and a Detroit Locker. Gabriel shocks were the latest technology at the time, and they were combined with coil springs that gave the vehicle 10-12 inches of wheel travel in front and 8-10 inches at the rear. Horsepower gains were from a 400-hp Chevy 350 CID V8 and a Ford C4 three-speed automatic (later upgraded to a C6). The vehicle also had a larger 22-gallon fuel cell, and a large functional wing was the "roof" of the cockpit that housed lights inside. Jones raced the vehicle at the 1970 Mexican 1000, and its performance stunned the off-road racing world until it broke on the course. Jones would later take Big Oly to win the 1971 and 1972 Mexican 1000 Baja races Overall and the 1973 Baja 500 Overall. BFG BLAZER While Big Oly won a few races, it had many reliability problems. Stroppe accused Jones of pushing the vehicle too hard, but all the talk caused Chevrolet to approach Jones with an idea to let him build the company's new Blazer for Baja. Jones again partnered with Dick Russel and built the Chevy Blazer as a stronger full-race vehicle in key areas. Off-road tires were unheard of in the mid to late 1970s, and to add to the Blazer's uniqueness, it was outfitted with new rubber from BFGoodrich Tires, which came out of extensive testing with racer Frank "Scoop" Vessels. The BFGoodrich All-Terrain T/A Radials were a success, launched a 46-year relationship with SCORE, and are the winningest tire in Baja racing history. As for the BFG Blazer, it had a full tube-frame chassis, a high horsepower Chevrolet small-block 350 CID engine, an Art Carr TH400 automatic trans, and a custom independent front suspension system with custom A-arms and Summers Brothers front hubs. It even had a large wing for the roof, similar to Big Oly, along with Gabriel shocks and a rear six-link suspension with a Sprint Car-styled Jacobs Ladder axle centering link. The BFG Blazer had similar wheel travel to Big Oly, 8 inches in front and 10 at the rear. Jones raced the Blazer for several years without a Baja win, so Chevrolet went back to Vessels, who drove it to win the 1980 SCORE Baja 1000 in Class 2. Bob Gordon and Don Adams also drove the Blazer to many victories. MICKEY THOMPSON'S CHALLENGER IV As an innovator, Mickey Thompson couldn't stand by and organize SCORE races without competing himself. He expanded on the Big Oly and the BFG Blazer platforms with a combination of his own. He combined a lightweight buggy chassis with a powerful 700 horsepower engine to create the Challenger IV, which debuted at the 1978 SCORE Mexicali 250 race as a Class 1 vehicle. With 41-inch long shocks made by Thompson, they were the first to use cooling fins on the body. The Challenger IV had 18 inches of rear travel and 15 inches of travel at the front from a torsion-bar suspension system. A two-speed Powerglide transmission handled the power, and large 33-inch tires in front and 36-inch tires at the rear provided traction. The car had a wing like the vehicles Parnelli Jones drove, but according to Thompson's son Danny Thompson, the wing stabilized the vehicle at high speeds. From 1978 to 1980, the Challenger IV was the fastest vehicle in Baja, but because of its speed, it broke almost every race. However, the car's legacy and innovation led to many modern-day ideas of what can work for an unlimited race vehicle in Baja. TRUCKS GET MODIFIED Following the successes of custom-built vehicles like the Baja Boot, Big Oly, and the BFG Blazer, many racers still couldn't afford a custom-built vehicle and began opting for pickup trucks because they were less expensive and were made to handle tough conditions. Around the late 1970s, these Class 8 trucks gained popularity, and racers such as Frank Vessels, Mark Stahl, Ivan Stewart, Walker Evans, Rod Hall, Robbie Gordon, and many others saw the potential. Because these vehicles came from the factory with a rugged suspension system, such as Ford's twin-I Beam and nine-inch rear end, they could handle the rigors of Baja racing with some modifications. At first, teams gutted the vehicles and added a roll cage and fuel cell. The engine modifications followed for more horsepower. Teams then added a tube-frame back-half behind the cab, allowing for more rear suspension travel and thus improving capability and speed. In the early days of Class 8 trucks, vehicles like the Filmore Ford were a perfect example that a powerful V8 engine nestled in a vehicle with a longer wheelbase and wide track width was great for Baja off-road racing. Many had multiple shocks front and rear, and with no bed, they could use the fuel cell's weight to help keep the vehicle balanced at higher speeds. While the vehicles looked stock, they were far from it; with wheel travel in the 12-14-inch range, they became the basis for more experimentation on what could be done to go faster, ultimately leading to the modern SCORE Trophy Truck. MORE POWER FOR BUGGIES While many factory teams experimented with trucks, the Buggies were still the unlimited four-wheel vehicles of the day. In the 1980s and early '90s, the Chenowth buggies advanced from small one-seat vehicles to two-seaters (Chenowth DR2) with a wider track width. This meant more room in the rear for a larger engine. Racers Scott and Mark McMillin took one and swapped out the VW four-cylinder engine for a 3.4-liter Porsche six-cylinder engine and transaxle. This brought more than 300 horsepower to the vehicle but still utilized a front VW link-pin suspension modified to be four inches wider. Bilstein shocks were the best at the time and vehicles like the McMillin's Chenowth they called "Macadu" used several on each corner and had 13 inches of wheel travel. At the rear, the VW swing-arm suspension was utilized with dual Bilstein coil-over shocks, and the vehicle could now use larger 33-inch diameter tires. Racers who saw the potential moved into this new unlimited buggy vehicle with other options of their own making. Bob Gordon, who had been successful in his Chenowth by winning multiple SCORE Baja 500 races in Class 2, outfitted one of the new Chenowth two-seaters with a more powerful Toyota V6, then later switched to a Chevrolet V8 and won SCORE Baja 1000 Overalls in 1987 and 1990, while also achieving many class wins. Adding more powerful engines continued as long as the transaxles could handle the power. Transaxle technology grew with innovations from Fortin, Weddle, and others to the modern Class 1 buggy, leading up to the Big Block Chevy power in the RPI Class 1 buggy built by Alumi Craft. Suspensions in Class 1 buggies also improved, allowing for larger 40-in tires and specialized chassis like the Jimco Hammerhead. Today, with advances in drivetrain and chassis building techniques, Class 1 buggies are still considered one of the ultimate Baja race vehicles. LAND SHARK TRUGGY The only vehicle that ever broke the "unlimited" Class 1 rules after complaints from other race teams was the Herbst/Smith Landshark. Builder Mike Smith and the Herbst Motorsports team bent the rules as far as they could go in 1995 and created a buggy from a SCORE Trophy Truck chassis and used a solid rear axle instead of a transaxle. They called it El Tiburon. This vehicle truly took the unlimited status to the edge with a large 454 CID Big Block Chevy engine, Turbo 400 automatic transmission, 39-inch tall tires, and multiple oversized shocks. Competing as a Class 1, it out-powered the competition to win multiple SCORE Baja 500 and Baja 1000 victories with Troy Herbst and Larry Roeseler behind the wheel. ENTER THE SCORE TROPHY TRUCKS With continued interest from truck manufacturers who wanted to use SCORE Baja racing to promote the capabilities and "toughness" of their vehicles, the SCORE Trophy Truck class debuted in 1994 and was given the "unlimited" status. This allowed manufacturers such as Ford, Chevrolet, Toyota, Nissan, and others to build custom vehicles and teams solely focused on off-road and Baja racing. Some of the first versions were upgraded Class 8 trucks with full tube chassis, more suspension travel, and greater horsepower. The suspension travel and horsepower kept increasing, which was achieved by limiting the powertrain to two-wheel drive. This also gave the Trophy Truck additional strength to withstand the abuse of higher speeds while allowing them to further evolve as the fastest vehicles in off-road racing. One of the first unique SCORE Trophy Trucks included the PPI Toyota built by Tom Morris and driven by Ivan Stewart. The Toyota Tundra featured a 4.9-Liter, aluminum block V8 engine making 550 horsepower. The truck was a single seater with the driver positioned in the center of the cab for better weight distribution, and the entire vehicle weighed only 3,900 pounds. An independent A-arm front and rear suspension gave the truck 22 inches of wheel travel with 37-inch diameter BFGoodrich Baja T/A KR Baja racing tires. THE NEXT EVOLUTION TT As more powerful engines made their way into the modern SCORE Trophy Truck, chassis, and suspension components had to be stronger and better to withstand the abuse of the terrain caused by faster speeds. Chassis designs improved the strength and rigidity of these vehicles, as well as driver safety and seating positions. The SCORE Trophy Truck evolved to Gen-2 And Gen 3 versions like this Brenthel race truck, which can be built for either a SCORE Trophy Truck or TT Spec. Capable of housing an 1100 horsepower engine, the latest Gen 3 models weigh about 5,750 pounds and have a 125-inch wheelbase and a 91-inch track width. Chassis are TIG welded for greater strength, and many modern SCORE Trophy Trucks feature a 100-gallon fuel cell, King 4.5-diameter shocks, and 3.0-diameter coilovers. Many of the body and interior pieces are made from carbon fiber, and improvements to the interior cab designs allow the driver and co-driver to feel more comfortable while also improving their field of vision. AWD SCORE TROPHY TRUCKS Although four-wheel drive, or all-wheel drive, has been present in SCORE since the beginning, the driveline components weren't as robust, which led to the dominance of 2WD SCORE Trophy Trucks. Teams such as the Herbst/Smith Terrible Motorsports and team McPherson with Chevrolet tried somewhat successfully with the latest 4WD technology of the early to mid-2000s but the components available had reliability issues. It wasn't until innovators such as Neil and Robert Mason understood that to have a successful AWD SCORE Trophy Truck, all the drivetrain components would have to be designed and built by the same builder instead of getting them from different vendors. The brothers designed drivetrain systems from the ground up. By 2017, Andy McMillin took one of their AWD trucks to a SCORE Baja victory. But after working out some of the issues in those first vehicles, AWD SCORE Trophy Trucks currently dominate Baja with speeds and never imagined capabilities. Teams are racing in the Baja desert faster than ever thought possible, and winning typically comes down to the team that makes the fewest mistakes and has the least number of flat tires along the way. The AWD trucks are changing the sport and have taken it to the next level, but this latest achievement could not have come without all the other vehicles of the past. "It's amazing what these AWD vehicles can do," said Fish. "But to take any vehicle 140 miles per hour in the desert also takes some driving talent. So along with the advances in vehicles, drivers have also adapted and have learned to read the terrain much faster. The important thing to remember, however, is that while some vehicles are awe-inspiring and have brought out the best innovators in the sport, SCORE off-road racing is for everyone. This is why we have so many classes, and it's also the diversity that makes this sport so great. Where else can you see a multi-million dollar AWD SCORE Trophy Truck and a Class 11 stock VW compete on the same course? It's still all about the challenge. The challenge you do as an individual and/or with a co-driver is to figure out how to go fast or slow, look at the terrain, and finish the race."