RC Car Becomes First To Hit 250 MPH After Wild Runway Record AttemptEight months of building, two days on a runway in Wales, and one very close call with a 90-degree slide during braking. British engineer Stephen Wallis has become the first person to drive an RC car beyond 250 mph, doing it with a machine he designed from the ground up and named the Mac Reaper.Wallis already held the Guinness World Record for the fastest battery-powered RC car, set at 234.71 mph with his previous build, the Beast.That record didn't last long.AdvertisementAdvertisementJames McCoy ran an unofficial 238 mph, which pushed Wallis to start over entirely rather than iterate. The result was Project 250 – a narrower, more powerful machine built around bigger motors, new electronics, and custom-machined components, with the stated goal of clearing 250 mph and 400 km/h in a single run.The new build keeps the general layout of the Beast while introducing several mechanical and electrical upgrades, including a narrower body to reduce drag, larger 5215 motors for more torque, and an expanded battery system running a 20-cell, 84V setup.Wallis described his ambition simply: "Today, I'm going to show you exactly how I'm evolving my RC car to beat my Guinness World Record of 234.7 mph and chase a slightly ridiculous goal: 250."How the 250 MPH Run Actually HappenedDay one at the Rosser event produced 182 mph, then 217 mph – impressive, but with a serious problem. Above 200 mph, the motor current was becoming wildly unstable, killing torque and preventing any further acceleration. Without a fix, 250 was out of reach entirely.AdvertisementAdvertisementDay two arrived with calm winds and a dry runway. Wallis returned to the exact motor settings he'd used on the Beast, ran the car at 215 mph, and checked the data logs. The instability was gone. He swapped to a fresh set of reinforced BSR teal-compound wheels after spotting rim deformation from the earlier high-speed passes, stretched the run-up as far as the runway allowed, and sent it. The result was 240.08 mph through the timing traps – a new world record, and the first RC car ever past the 240 mph mark. He was unsatisfied before the car had even stopped rolling.For the 250 mph attempt, Wallis made a decision that he described as "slightly ridiculous": he trimmed the worn inner edges off the used tires, narrowing them by roughly 10mm. The logic was sound. Less material, less drag, nothing to lose. He then had a crew member carry the Mac Reaper to the very far end of the runway to maximize the run-up distance before sending the car from almost out of sight. It ran the full length, hit 250.67 mph and 250.21 mph through the dual timing traps, slid sideways during braking, and came to a stop upright. GPS data later confirmed the peak speed at 251.78 mph, nearly 2 mph past the original target."What a day. I should have bought a lottery ticket," he said. "The 240 mph run could easily have been a 239. The 250 mph run could easily have been a 249. The weather was perfect. The car was flawless. It came back every run, no problem. Somehow everything came together at exactly the right moment."Wallis has confirmed the project isn't finished. With three events left in the season and the pressure of the 250 mph target gone, the question now is how fast the Mac Reaper can actually go. Tires remain the limiting factor, and Wallis hasn't yet had a run where the car felt like it was out of road. That gap between what it's done and what it might do is exactly the kind of problem that keeps engineers up at night – and keeps the rest of us watching.
+54 others
