Born To Race: David Hartman’s Ultra4 4800 Buggy

David Hartman, an Ultra4 4800 class driver, once hailed from the Midwest, specifically Illinois, where he grew up racing motocross. In his late teens, he was a 250B two-stroke rider. Why motocross? Hartman said, “It was the only thing to do in Illinois until all the tracks started closing down.” His favorite track was Loretta Lynn’s motocross track in Tennessee. I understand why this was his favorite track, and for those that do not, the dirt is the best for motocross racing. Only a few tracks fall into the same category.

After college, Hartman moved to Florida where he owned a few businesses. After watching YouTube videos on King of the Hammers, he took an interest in rock racing. As we all might know, Florida is not the best state for rockcrawling, and sand castles would fall apart driving over them. Hartman eventually moved to Colorado, where he got back into the idea of rock racing. When asked why four wheels over two wheels, his statement was, “With age comes a cage.”

This car handles very well. It has an awesome profile.

Hartman debuted his rookie season in 2018. He took second place in the West Coast division and placed fourth in the nation that season. David is currently sitting second on the in the West Coast division and fifth in the nation for 2019, with a second-place finish at the Metalcloak Stampede and a third-place finish in the inaugural King of Baja, a new Hammers-style race in Baja, Mexico.

In the Ultra4 4800 class, they have a spec chassis design known as the “podium chassis.” Hartman contacted Jimmy’s 4×4 out of Cortez, Colorado to build a race car with this chassis in mind. Hartman started with a Jimmy’s version of the podium chassis and took some designs from Nick Nelson and Loren Healy to add to his design. Several changes were made to the rear of the chassis to raise the rear to gain 28 inches of travel, all done within the Ultra4 4800 class specifications.

The Engine

To power his Ultra4, Hartman sought out Turn Key Engines. They built a stroked LS3 with all forged internals. Holley EFI delivers the fuel mixture to the engine. The engine cooling is done using CBR radiators and a Spal fan to pull air through the radiators and coolers. All of the engine parts are lubricated using Schaeffer Oil.

The engine compartment houses a stroked LS3.

The Drivetrain

To get the horsepower from the engine to the wheels, Hartman had Randy Rodd, owner of Jimmy’s 4×4, build one of his racing transmissions. Rodd started with a GM three-speed automatic Turbo 400, then made some modifications to the case so it accepted Rodd’s patented racing valve body. Then the real work began. Rodd rebuilt the shifting to a mechanical shifter to let Hartman choose which gear he needed, either in the rocks or on open road.

Then he added a Hero two-speed transfer case to split the horsepower to the front and rear axles. From the transfer case, the horsepower then runs through a pair of Adams driveshafts to Gearworks third members, through the a 5.83:1 ring and pinion out to a pair of Spider Trax axles. In the front axle, a pair of Yukon Super Joints provide power through the steering as the rig goes through rocks or turns.

Here is the suspension setup, showing the four-link and King Shocks.

The Yokohama tires give plenty of traction on the rocks or dirt. They also add to the overall height and boost the ground clearance.

Taking the horsepower to the ground, Hartman uses Ultra X103 17×9 wheels and has a set of Yokohama 37×12.50R17 Geolandar MTs for the mud and snow, or Geolandar X-MTs for rock crawling and dirt.

The Steering

The steering is controlled through a rack and pinion system from PSC, which is great for those small turns on the rocks. To dampen the ride on those rough trails, each corner has a single King 3.0 IBP coilover shock. coinciding with the limit-one constraints in the 4800 class. To get the best performance and ride, Hartman had Nick Nelson Motorsports tune the shocks. “He did a great job tuning my shocks,” said Hartman. Hartman keeps the fuel on his Ultra4 in a Pyrotect fuel cell.

The Pyrotect fuel cell and King shocks.

When rockcrawling or desert racing, everyone within the vehicle needs to be comfortable, so Hartman had a pair of PRP seats and belts installed for those bouncy roads on the course. To make sure Hartman and his crew can talk to each other, a Rugged Radios setup was installed in the rig.

When the race goes into the night, KC HiLiTES lights up the course ahead. There are eight KC Flex LED lights and a 10-inch KC Array LED light bar. All have the yellow lens covers to help cut down on the glare from the dust.

Once the parts were ordered and sent to Jimmy’s 4×4, the build all took place in house. All interior and exterior sheet metal was designed, bent, and drilled to mount on the chassis. All brackets and mounting points were made and welded in place before the wiring and plumbing made it race-ready.

When he needs to see at night, David uses KC HiLiTES Flex LED light pods and an Array LED light bar.

Up front, behind the push bumper, there’s a Warn 9.5 CTI winch with synthetic rope. A Factory 55 Road Guard protects the rope loop, and an UltraHook is for those times Hartman needs to get a little help on the course.

To power all the electronics, David went with an Optima Red Top battery. This gel battery will hold up to the roughest of rock or roads, and will work upside down if he is no longer on his wheels. There is no need to worry about acid going everywhere with this battery.

The Warn 9.5 winch and Ultrahook. The winch is protected and mounted high, offering clearance to get closer to the rocks or trail.

One important item every racer must wear is a fire suit and helmet. Hartman uses the latest fire suit made by Alpinestar and an Impact helmet. His team uses the race helmet that hooks into a fresh air system to not have to breathe all the dust from the guy in front of him.

Making The Vehicle Special

I wanted to know what made this car so special for Hartman. In his eyes, it’s the rearend. The car is sitting with a 118-inch wheelbase and is longer than most of the Ultra4 class. Along with that, 28 inches of travel in the rear make this car phenomenal.

The car handles very well in the desert and on the rocks. It’s super-competitive for long distance events and short courses as well. This might be the future setup for this Ultra4 class.

David uses a Rugged Radio set so driver and passenger can talk to each other. Also seen here are the seats, Yokohama tire and Ultra Wheel, and Optima battery.

Every Man Challenge

Looking at some of David’s past events, he’s been able to finish the Every Man Challenge. I wondered: What does it take to survive Every Man Challenge? “If you want to win at Hammers, you must be there twice a year to prerun the course,” explained David. “Then you need to be there a week early to view the course.”

“Things change over a year,” he continued. “Therefore, you need to see what has changed. It takes some major dedication at this race just to do well.” Hartman will be looking forward to the next Every Man Challenge and will be taking the knowledge learned from the prior races with him in 2020.

Whether it is playtime in Moab or racing in Johnson Valley, the car handles all of the different terrains.

In 2018, Hartman left the line with only 20 minutes of seat time in the new car. A year forward, Hartman qualified fifth at the start. He got into a predicament in Cougar Buttes. After a lengthy recovery, chased down 25 cars and made it back to finish the two-lap race.

Hartman placed 29th out of 48 that did finish the course; his time was 8:51:28. At the start of the race, 134 drivers left the line and 86 either never finished the first lap, or never made it through the second lap. The Every Man Challenge is a very tough race and for the most part, harder on the equipment.

David's Ultra4 4800 class car sits with a great stance.

What’s Next for Hartman?

The Ultra4 will be in Ridgecrest, California, September 13, for the Lasernut Western Series. Last year, they raced at night and started after the 44oo class, which was extremely hard on the competitors. They will not be doing that this year, and the class is looking forward to a clean race course.

Next up will then be the weekend of October 18, in Reno, Nevada, for the Nitto National Championship. It will be the last race for the 2019 season. Hartman can be followed on his Facebook page or Instagram.

Photography by David Chick

Article Sources

About the author

Scott Spinning

Scott has been freelancing as a motorsports photojournalist for 38 years. he has been published in several national magazines also in a local and national tabloid. He loves the smell of racing fuel and the sound of a large horsepower engine roaring.
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