Meet the couple that built an EV rock crawler for King of the Hammers

When you think of an electric vehicle, you likely think of the ubiquitous Tesla, making its way on a daily commute. Maybe you think of a luxury Lucid Air cutting through the air with nearly no drag on a canyon road. A handful of you might picture a Rivian R1T toddling down a smooth dirt road.

What you likely don’t think of is an EV ready to tackle the off-road rock trails with 37-inch tires, solid axles front and rear, massive articulation, and a two-speed transfer case. Thankfully, Keith and Melissa Silva of EVolve Racing have a bit of vision.

For this year’s King of the Hammers race festivities in Johnson Valley, California, the Silvas swapped the powertrain in their old Chevrolet S10 rock crawler with a Tesla Model S and raced it in the 4Wheel Parts Every Man Challenge as car No. 2412.

What the heck is King of the Hammers?

For those not in the know, King of the Hammers is an event like no other. This year, 80,000 people gathered on Means Dry Lake bed from February 4th–11th to watch a variety of races during the week. Drivers battle the open desert full of whoops, soft sand, and steep hill climbs that challenge even the quickest of cars.

After that section, the same cars must conquer rock trails that must be seen to be believed. Boulders as big as Smart cars. Hills at an angle that would make your geometry teacher weep. This is rock crawling at its finest, except it’s done at speed with plenty of rigs rolling over — or climbing over each other. It is complete and utter chaos, a combination of Burning Man and Mad Max.

And the Silvas decided to take an EV.  

As unlikely as it may seem, this isn’t the first time an electric rig has raced out here. In 2021, Kyle Seggelin finished the Every Man Challenge in an old 4Runner equipped with a Nissan Leaf powertrain. However, his only task was to finish the desert loop. The Silvas would have to complete one lap in the rocks as well.

Electrified powertrains are not favored by many rock-crawling fans; heck, even Keith himself said he loves the sound of a V8. However, during its week on the lake bed, the TesTen — a combination of Telsa and S-10 — garnered a lot of attention from onlookers curious about what is or is not under the hood.

The Silva’s rig has a motor and battery from a 2015 Tesla Model S P85. Using all 16 modules from the battery, they have 85 kWh of juice to get them as far as they can. The single motor produces 416 horsepower and 443 pound-feet of torque, much less than the myriad V8s the other competitors run. The difference here is that torque is available quicker and at slower speeds, which is exactly what you want in a rock crawler. 

The addition of a low range kind of blows my mind. In a gas-powered machine, low range is used to ensure high levels of torque at low engine rpm. If that torque is right there under your foot, available instantly, why add the weight and complexity of a low range? Keith says it’s to keep the motor from generating too much heat. While there are three Mishimoto radiators on board to cool the battery, motor, and inverter, the low range provides a happy medium between using all that torque at once and stressing the motor. 

The couple built the rig in their garage over 10 months. They had sponsors come in with products, like Mickey Thompson tires, Rugged Radios, and Raceline Wheels, but Keith says they did have to take money out of savings. It didn’t come to the point of maxing out their credit cards, but the team still put $60,000 into the truck. Keep in mind that all they did was swap powertrains. They already had the rig with suspension components and axles. Had they built the car from scratch, it would easily top six figures. 

No testing? No problem!

Even with a 10-month build time, when the Silvas arrived at Means Dry Lake on a Monday for King of the Hammers, they still hadn’t tested the truck. With the race looming the following Friday, the team spent the few remaining hours turning their electrical gremlins into lawn gnomes. Annoying but tolerable. 

When the sun rose on February 10th, the TesTen made its way to staging. It would be starting last out of 155 entries, tasked with completing 95 miles of desert racing and 48 miles in the rocks for 143 miles of the craziest racing on the planet. And they didn’t even know how far they could go on a single charge.

“We’re hoping for 80 to 100 miles of range, but we really don’t know,” said Melissa. “The most we’ve ever driven it is 35 miles.”

Further, the TesTen never got its sophisticated battery management system, so Keith was leery of charging the battery past 80 percent. Sure, it’s not a good idea to charge to 100 percent every time, but to not even do it even once? That’s a huge disadvantage.

Charging in the desert

The first problem cropped up not even five miles from the starting line. The inverter was struggling, and the TesTen couldn’t make it up the first sandy hill climb. A reboot of the system was required, but the couple did not have a laptop with them. Keith was ready to call the race, but Melissa had other ideas.

King of the Hammers is a no-chase race. Competitors can not accept outside help unless in a designated pit area, so Melissa had one choice. She had to run back to the main pits and get the laptop. It took her two hours, but they were able to reboot the system and were on their way again.

Even after taking it slow for the first 25 miles, No. 2412 arrived at the first pit area with a 25 percent state of charge. Knowing that their “full” battery is only 80 percent, the team used 55 percent of their battery to race 25 miles. That is a little over a half a mile per kWh in efficiency. Good Lord, that’s worse than the GMC Hummer EV’s efficiency. I didn’t think that was possible.

Fortunately, the team was allowed to charge at the first pit stop. Optima Batteries showed up with its portable Level 2 charger, but the team hooked up to Hypercraft’s Ford F-250, and tow charged — using regenerative braking is faster than Level 2 charging. However, not ones to look the proverbial gift horse in the mouth, the Silvas grabbed a few electrons from Optima, leaving the pits with an 80 percent state of charge.

The team upped the pace for the next section, hoping to make it back to main pits for another charge before heading into the rocks. But it was not to be. Their quicker progress drained the battery to almost nothing, and though the team was so close to completing their lap they could smell the exhaust from their V8 competitors, they decided not to deplete their battery and risk damaging it.

Refueling of any kind, gas or electrons, must take place in the pits, so the Silvas were essentially out of the race. The husband and wife team had to wait until the race was finished at 6PM before they could be recovered. 

Sitting in No. 2412 with the cold wind blowing dust and sand into their faces through the open cockpit, the sun dipping below the hills to the west, and the chilly night air setting in, the Silvas couldn’t have been happier.

“I was excited that we got to pit 1 and we still had juice left,” said Melissa. “We didn’t break, we didn’t get hurt — the truck is in a great state. Everything that we’ve done is a win. We’re both ready for it to be next year.”

We’ll see more electrified powertrains next year with a new EV spec class. Ten teams have been given a 40 kWh battery from Hypercraft, an electric motor from Spicer Electrified and a control unit from AEM Electronics. Race organizer Dave Cole will allow teams to build any chassis around that powertrain, so expect to see some cool hand-built electric side-by-sides and traditional trucks next year.

The TesTen will continue racing, albeit in short-course rock crawling competitions, which usually last 10-15 miles. However, I have a feeling they’ll be back at Hammers next year. The couple may add swappable batteries to the TesTen to avoid the hassle of charging in the pits, and I wouldn’t be surprised to see a laptop strapped into the rig somewhere.

In the time leading up to the race, all I saw from the Silvas was absolute grit and determination through the late nights and early mornings, always with an upbeat and positive attitude. If anyone can get an EV to the finish line at the most gnarly off-road race in the world, it’s these two.