AT ABOUT 2:30 p.m., Radio BUB crackles to life. Rocky Robinson and the Ack Attack inch over the start line, followed immediately by Akatiff in his black Dodge pickup. The truck's bumper is rigged to give the tippy streamliner a 40–mile–per–hour running push. Within a quarter–mile, Robinson hits the gas, turning the docile streamliner into a pissed–off cheetah. There's a deafening growl as the Ack Attack roars away.

Outside the realm of land–speed racing, Robinson is a mild–mannered guy who gels his black hair to spice up his insurance–salesman looks. He manages a tile store in Grass Valley, but he used to have a more exalted job as a corporate vice president for Manning, who unceremoniously ousted him in the fall of 2005 during a temporary economic slump. Getting the boot also meant saying goodbye to Manning's streamliners. The dismissal still makes him mad.

"I helped turn that company into a multi–million–dollar business," Robinson will tell me later, away from the salt. "Where I work now is about eating and keeping the lights on."

As Robinson accelerates down the track, he puts himself on a tactical tightrope: Too hard on the throttle and he could spin the rear wheels and lose valuable momentum. Not aggressive enough and he won't wring out all of the Ack Attack's potential. Robinson runs through the bike's six–speed transmission by redlining every gear, shifting only when a gear–change light comes on inside the cockpit. In Bonneville's unchanging, canvas–white landscape, the beacon is one of Robinson's best visual indicators that he is, indeed, hauling ass.

At mile five, Robinson anxiously feels a crosswind that causes the Ack Attack to list to the left. He doesn't fight it, instead letting the bike drift even farther left, toward the edge of the 120–foot–wide track, the course markers, and the portable johns. He has to. Unlike regular motorcycles, streamliners don't turn when leaned, so Robinson can't change directions until he gets the motorcycle's mass reoriented directly over its wheels. Once he "catches" the bike, he carefully steers his way back to middle.

The power of the machine is incredible. Akatiff's recipe for a successful streamliner includes two highly potent Suzuki Hayabusa motorcycle engines. In the Ack Attack, they generate a racecar–like 900 horses, thanks to the addition of modified pistons and connecting rods, high–octane racing gasoline, and an oversize, whining turbocharger capable of force–feeding huge gulps of air into the engines' combustion chambers. All that power goes to the rear wheel via custom–made transmission shafts and industrial–strength racing chains, which get so hot that Akatiff uses nozzles to constantly spray them with ice water.

When Robinson enters and exits the mid–course, mile–long timing trap, he sets off lights located at each end, which capture his average speed. By this time he's covering two football fields per second. The tires are designed with paper–thin tread to avoid excessive heat buildup; otherwise they might boil and melt off the rims.

At the far end of the course, Robinson hears the good news: He reached the unprecedented speed of 344.673 miles per hour. But nobody is high–fiving just yet. The rules state that he has to make a second, return run within two hours. (The second run negates any advantage gained from tailwinds; the two hours give crews time to make repairs.) His official speed will be the average of the two runs.

Minutes later, Robinson takes his second run, going back through the trap with a whoosh. From the pits, which double as the meet's front–row seats because they're located dead–center on the track (but safely off to the side), the Ack Attack's run sounds hyperbolically fast, with a jetlike shriek that arrives just after you watch the thing streak left to right across the horizon. Even before the bike comes to a halt, the results are announced over the radio: "Streamliner through the mile, 340.922. Average speed: 342.797."

Just like that, in his first set of runs, Robinson has smashed the 16–year–old record. He climbs out, pumps a fist, and finds Akatiff to deliver a hug. No sooner is the bubbly spilling than the boss pulls Robinson aside.

"So far, so good, Rocky," he says. "We're right on plan. Now we're going to see what we can do to go faster."