Dennis Anderson is an extremely charismatic man. You'd never know that this 58-year-old is lovingly known as the king of monster trucks.
Anderson fondly tells me about an old coworker who used to make fun of his 1951 Ford truck, calling it a piece of junk. Anderson responded with, "I'll take this junk and I'll dig your grave." That weekend, Anderson used a bulldozer to carve out a truck playground, big mud pit and all, and invited his naysaying coworker to come out and play. With "Gravedigger" spray painted on the side of that Ford, Anderson showed his foe who's boss.
That grudge match started what is now one of the most popular events in the motorsports world: Monster Jam.
Monster Jam used to focus around just two events: racing, either timed or head-to-head, and freestyle, where drivers get a limited amount of time to impress judges and fans with wheelies, flips, jumps and more.
Today, monster truck drivers have to be a bit more well-rounded. For starters, Monster Jam now has the very popular two-wheel competition, where points are awarded for the best stunts performed on two (or even one!) wheel. In addition, Monster Jam drivers have to be able to race small, too, competing on both ATVs and vehicles known as Speedsters, which are essentially caged side-by-sides that are super nimble, but also hard to handle.
Of course, it's the big trucks that attract the fans. Monster trucks are 12,000 pounds of car-crushing hell on wheels. But it turns out they have a bit of trick tech, as well.
Monster trucks can produce as much as 1,500 horsepower and 1,320 pound-feet of torque from their supercharged, big-block engines. Most truck use 572-cubic-inch engines, but Gravedigger runs a slightly smaller, 540-cubic-inch unit. The giant monster hearts are built to last for 32 hours of hard driving. That might not seem like a long time, but remember, these motors are constantly subjected to insane forces of gravity, and have to perform flawlessly while sideways, upside down and everywhere in between.
The engines send power to all four wheels through a two-speed transmission with a mind-blowing 22:1 final drive ratio. That means the trucks have tons of torque available at all four wheels, but don't have a high top speed. That's fine -- remember, these trucks are all about short bursts of power. A high final drive ratio is better for initial acceleration.
Monster Jam mechanics have worked out a way to ensure those transmission work even while the truck is in a vertical wheelie stand, where the driver might shift from reverse to first gear and back in quick succession. A transmission pick-up with a valve at either end of the case ensures that fluid is running no matter what position the truck is in.
As for the trucks' massive tires, each one is 66 inches tall with 43-inch-wide tread. The BKT tires are wrapped around 25-inch beadlock wheels, and are inflated to just 23 psi. All told, each wheel and tire weighs 645 pounds. That's a Mazda Miata's worth of weight and then some, just in wheels and tires.
While all four wheels get power, they don't all have brakes. Instead, braking is done on the drivetrain itself. Additionally, drivers can choose their own differential locker setup. Some drivers run with the front and rear locked all the time, but others prefer an auto-locker that just evenly distributes the power when needed. Regardless, all Monster Jam trucks have rear-axle steering to help these behemoths make tight turns, which is especially important in smaller stadium scenarios.
But when it comes time to jump 30 or 40 feet in the air and then land safely, it's the shocks that are the most important. Two bypass shocks with remote reservoirs live at each corner, filled with nitrogen pressurized to 320 psi up front and 420 psi at the rear. These shocks are adjustable on the fly, so drivers can set one pressure for racing and quickly switch it up during the freestyle or two-wheel competitions. Most monster truck setups allow for 26 inches of front wheel travel and 30 inches of rear wheel travel.
Given the hardcore tomfoolery demanded of these trucks, driver safety is of the utmost importance. Each monster truck driver wears a three-layer fire suit, as well as fire-resistant gloves and shoes. Helmets and a neck restraint are required, as are five-point harnesses, in-cab fire extinguishers and a remote ignition interrupter. The latter allows crew members to remotely shut off the truck's power and fuel in case of an emergency, or if the driver is headed toward danger they might not be able to see.
Speaking of drivers, I personally love Monster Jam for its commitment to hiring female drivers. Right now, Monster Jam has 14 female and 75 male drivers, which is one of the highest ratios I've seen in just about any form of motorsport.
The women aren't just token diversity hires, either -- they're some of the best out there. At the Monster Jam World Finals this year, Cynthia Gauthier won the high-jump competition, throwing her Monster Mutt truck 45.472 feet in the air. Linsey Read, who drives the Scooby Doo truck, beat out seven other competitors just to participate in the World Finals, and then turned in a spectacular freestyle session for the win.
But without question, the most passionate folks at Monster Jam are the fans. These folks come out in any kind of weather to attend huge pit parties, where they can check out the trucks up close and talk with their favorite drivers. What's more, Monster Jam makes sure its drivers are accessible to fans. Want to take a selfie with the driver of Gravedigger and then get an autograph? No problem. Good luck doing that with Lewis Hamilton.
Monster Jam travels around the world, and chances are one is headed your way sometime soon. Over the past two seasons, Monster Jam thrilled 8.7 million fans in 120 cities across 44 states. Outside the US, Monster Jam shows take place on six continents in 33 cities in 21 countries. It's a huge production, with pyrotechnics, loud music, and of course, those awesome trucks.