Ken Frankel is a mechanical engineer whose company machines implausibly complex aerospace components to improbably precise tolerances. So it’s surprising to find him in the paddock of Mazda Raceway Laguna Seca wrenching on an earthbound vehicle whose puny wheels wouldn’t look out of place on a clown car and whose engine is no bigger than the ones powering garden mowers. He carefully maneuvers the vehicle onto a set of scales–one for each low-profile tire–that have been leveled with a laser to within 30 thousandths of an inch. Accuracy is critical; the chassis responds to differences in corner weights of as little as 2 pounds. The ride height, meanwhile, is adjusted in increments of 1/16 of an inch.
“You’re looking at the convergence of the highest imaginable performance in the smallest possible package,” Frankel says. “This is not a go-kart.”
Actually, it’s a super_kart, and it’s not to be confused with the putt-putt-mobile your father slapped together out of leftover steel tubing and a misfiring chainsaw motor. Powered by a race-proven 250cc motorcycle engine with a sequential-shifting six-speed gearbox, a superkart has as much in common with an amusement park ride as an F-22 has with the _Wright Flyer. Carbon-fiber bodywork is commonplace. So are aluminum components, titanium fasteners, disc brakes, electronic engine management and onboard data-logging computers. What we’re talking about is the most bang for the buck in the motorsports universe–racetrack performance that costs less than a minivan but makes a Lamborghini look lumbering.
“It’s such a rush to drive. In fast corners, you feel like your head is going to be ripped off,” says Eddie Lawson, who races the superkart Frankel is preparing. “If I could afford it, I’d have my own Indy car to play with. But that would cost a couple of million dollars, and I’d need a whole team of guys to work on the car. With the superkart, I can head out to the track
by myself, and it stops, goes, turns in, and corners just like a proper open-wheel racecar. In some respects, it’s even more fun than an Indy car because you can really toss it around without losing control, and a good driver can make up for a bad ride. It’s a real kick in the butt to drive.”
This isn’t some Mario Andretti wannabe blowing smoke. Lawson, 45, is a four-time 500cc motorcycle World Champion who raced Indy cars for a season before retiring from professional motorsports. He now scratches his racing itch by trouncing the competition at selected amateur events in his state-of-the-art superkart. He’s here at Laguna Seca, in Monterey, California, in early September to compete in the most prestigious international event on the superkart calendar. This race–which is interspersed with more traditional automobile race events over a three-day weekend–is the crown jewel of the five-part World SuperKart Series, which southern California kart builder J.R. Clasen founded in 2001 to raise the sport’s lower-than-low profile in the United States.
Despite a top speed of nearly 150 mph, superkarts don’t get much respect. “Considering how much fun they are, they aren’t as popular as they ought to be,” Lawson says. “For the big-time sports car guys, a superkart is less than their tire budget for the year. But when they fly into town in their private jet with their girlfriends, they don’t think the superkarts look as cool as their Ferraris.”
Although the race this weekend is officially known as the World SuperKart Challenge, it could be billed more properly as the Beat Eddie Lawson Invitational. More than 50 drivers from England, France, Australia, Canada and all over the United States are here to see how they measure up against the sport’s living legend. Most of them are well-heeled middle-aged thrill-seekers out for a good time. “This is like having sex all week long,” jokes Bill Busacca, a dentist who drives for Old Farts Racing. (Team slogan: “The older we get, the faster we used to be.”) Only a handful of drivers have a legitimate shot at defeating Lawson. Even reigning European champ Damien Payart has his doubts. “He is very fast,” the sad-eyed Frenchman says ruefully.
Lawson’s most formidable opponent appears to be Mark Owens, a Brit who, at 29, is already a hard-bitten veteran of the kart wars. His crew chief (and father) Paul Owens worked for decades designing open-wheel racecars, and helped develop the first carbon-fiber chassis to be used in anything other than Formula 1. “I’m here to knock (Lawson) off his pedestal,” the younger Owens says.
Laguna Seca begins Friday with a qualifying session. Today, Saturday, there’s a preliminary race whose results will determine the starting grid for Sunday’s 30-minute main event. Lawson and Owens start 1-2 and run that way until Owens falls back with a gearbox problem. Lawson wins, averaging 97.89 mph around the 11-turn, 2.38-mile road course; Payart is second, Owens third. Twenty-three-year-old American tyro Ron White is a fighting fourth; his kart, made for him by Los Angeles dentist-cum-racer Pat Yoshikane, invokes envy from rivals (“many of the parts are magnifique,” says Payart). Fifth goes to Lawson’s close bud and teammate Wayne Rainey, 42, a three-time 500cc motorcycle World Champion who races a superkart with hand controls developed after he was paralyzed from the chest down in a 1993 bike crash.
The results aren’t unexpected. But the speeds are mind-boggling. Jaw-dropping. Awe-inspiring. Although the superkarts max out at about 130 mph on the relatively short uphill front straight, they carry an insane amount of momentum through the sweeping turns, generating lateral cornering loads of 2 Gs. (That’s half the G-load of a Champ car but twice that of most sports cars.) The chassis are so light and nimble that drivers dart around like badly spooked squirrels on a caffeine high. “The first (practice) session on Thursday was really frightening,” says 24-year-old Kyle Martin, a perennial champion in smaller 125cc shifter karts who’s getting his baptism of fire in a superkart.
The headline attraction this weekend is the American Le Mans Series, which features sports cars racing on the same track as the superkarts (though at different times). The stars of this series are multimillion-dollar thoroughbreds known as Le Mans Prototypes, or LMPs. But the Audi R8, winner of three consecutive 24 Hours of Le Mans, is only 7.6 seconds, or 10 percent, quicker than Lawson’s superkart over a 76-second lap. And Lawson is just as fast as the ex-F1 studs driving Ferrari 550 Maranello racecars–machines that go for $1 million a pop–in the GTS class behind the Audis. As for the less exotic Ferrari 360 Modenas and Porsche 911 GT3s, they seem to wallow around the track like pregnant cows.
The crowd can’t believe what it’s seeing. Neither can the sports car drivers. After a session in his comparatively monstrous BMW M3, Boris Said comes over to gawk at Lawson’s kart. Said, the reigning Trans-Am champion, is accustomed to honking 650-horsepower pony cars massive enough to reduce a superkart to roadkill. “Awesome!” he says, shaking his head. “Yep, one of these days, I’m going to get one of these things for myself.”
The commonly accepted creation myth of the go-kart is set in Glendale, California, a suburb of Los Angeles, in 1956. Here, in the shop of the mighty Kurtis-Kraft company, birthplace of the roadsters that dominated the Indianapolis 500 during the 1950s, a fabricator by the name of Art Ingels spotted a surplus lawnmower engine in one corner and steel tubing in another. He put the two together and fashioned the world’s most inexpensive high-performance wheeled vehicle.
Go-karts developed along much the same lines as racecars. The need for speed spawned more complex technology, which cost more money, which funded better gizmos, which generated higher speeds, which is how we got from Ingels’ crude contraption to Lawson’s high-tech rocket ship in less than 50 years. “In terms of training, I could jump directly from a superkart to an LMP car,” says 24-year-old Alan Rudolph, who’s competing at Laguna Seca in both a superkart and an open-wheel racecar called a Star Mazda. “But in the eyes of car sponsors, a superkart is just a go-kart, so I have to drive the Mazda to be taken seriously.”
Whereas in the United States go-karts are generally dismissed as toys, in Europe and South America they’ve long served as stepping-stones to careers in auto racing. For many years, the preferred model was a single-speed, direct-drive 100cc machine that raced on special kart tracks that were much shorter and twistier than auto-racing circuits. Karts with bigger engines–the first generation of superkarts–were introduced in Europe in 1969, but their popularity waned. Then, about 15 years ago, in the never-ending quest for speed, enterprising karters in southern California started stuffing motocross engines and gearboxes into their chassis. These 125cc shifter karts were such a hit that it was just a matter of time before somebody decided that bigger was bound to be even better.
But the twin-cylinder 250cc shifter karts that resulted proved too powerful for kart tracks. Moving to full-size car circuits was a no-brainer, but the higher speeds achieved on these longer racetracks spotlighted several deficiencies in existing kart chassis: The short wheelbase made the machines diabolically twitchy, and their width added scads of drag. As a result, the Commission Internationale de Karting, based in Switzerland, developed a formula for 250cc shifter karts designed to race on automobile circuits, and the modern superkart was born. Superkarts have longer wheelbases than conventional karts (for better stability through high-speed corners) and heavier minimum weights (to promote more robust chassis), and they are narrower (to generate higher straight-line speed).
In many respects, a superkart is a car writ small. One fundamental difference is that superkarts don’t have springs to suspend the wheels or shock absorbers to dampen them. Instead, the chassis serves as the suspension. While a lot of racecars are built around carbon-fiber tubs designed to minimize chassis flex, kart frames are
still welded together the old-
fashioned way out of steel tubing, because a certain amount of chassis flex is required. Driver flex, too, is par for the course.
“One thing that makes the racing experience so exciting is that you feel like you’re part of the kart,” says J.R. Osborne, a 36-year-old real estate developer and ex?Formula car racer who drove 26 hours straight from his home in Denver to make the race at Laguna Seca. “The downside is that karts are much more extreme than cars, much more violent,” he adds, referring to the formidable G loads and molar-rattling vibration. “If the track is too rough, you literally can’t see.”
The other big point of departure between automobiles and superkarts is the powerplant. The four-stroke engine technology that is found in virtually all street cars is used mostly in slower karts. The hot setup is a two-stroke engine. That’s right, the annoyingly whiny, smelly, smoky buzz-boxes that power many lawnmowers, chainsaws, dirt bikes, even radio-controlled model airplanes. Two-strokes spew out a lot of pollutants, suck down a lot of fuel, and don’t last very long. But they sure go like stink.
For example, Lawson’s Yamaha TZ250 develops 90 horsepower from a 250cc engine: That’s 360 horsepower per liter. A stock Corvette makes less horsepower–350–out of close to 6 liters. Even Jeff Gordon’s Nextel Cup stock car produces only 130 or so horsepower per liter. And with the Yamaha engine shoehorned into a container not much larger than a breadbox, Lawson’s superkart boasts a power-to-weight ratio better than virtually every production car in the world short of the $670,000 Ferrari Enzo.
A two-stroke engine is less-is-more philosophy in motion. A cylinder in a four-stroke requires two revolutions of the crankshaft to complete its four distinct cycles–intake, compression, combustion and exhaust. In two-strokes, intake and compression are combined in one cycle and combustion and exhaust in another, so each cylinder produces power with every revolution of the crank. Also, two-strokes don’t have conventional intake and exhaust valves, which means they don’t need camshafts to actuate a complicated (and often fragile) valvetrain.
Top-of-the-line superkarts are motivated by twin-cylinder 250cc two-strokes, some of which spin faster than 13,000 rpm. Typically, an extra carburetor jet enhances top-end performance, while the exhaust port stays closed longer at slower speeds to produce low-end grunt. Special attention is paid to the shape of the exhaust pipe, which is technically known as an expansion chamber. “You can put on bigger carbs and you can run higher compression,” says longtime engine builder Sandy Rainey, Wayne’s dad, “but the pipes are where most of the power comes from.”
Superkarts stop as well as they go, thanks to disc brakes front and rear. (Frankel fabricates Lawson’s rotors out of an aluminum-based metal matrix compound to save weight.) They also generate oodles of mechanical grip through wide, treadless tires. Aerodynamically, though, superkarts are relatively primitive, because the drivers must punch a huge hole in the air. (Sure, you can run fully enveloping bodywork, and some racers have, but that’s problematic too–“It stiffens the chassis too much,” says Paul Owens.) Still, superkarts are very sensitive to aero tuning. The standard practice is to adjust the nose of the kart, lowering the ride height to increase downforce, and balance the aerodynamics by trimming the angle of the rear wing.
A good superkart costs about $15,000; figure 30 grand for one with every option known to man. It ain’t cheap, obviously, but it’s a bargain by motorsports standards. “I hate to say it, but it comes down to ego,” says Randy Taylor, 47, an American Airlines Boeing 767 pilot who’s another car racer turned superkart fanatic. “If everybody had zero ego, everybody would be racing superkarts.”
Forty-nine superkarts stream onto the track Sunday morning, forming what appears to be a long, multicolored snake as they buzz around on their warm-up lap. By virtue of winning yesterday’s prelim, Lawson starts the race from the pole–the inside position of the front row. But when he sees the green flag and floors the throttle, his Yamaha sputters and his kart bogs down. (He finds out later that the fuel line had come loose, allowing gasoline to spray out.) White, a 125cc-shifter-kart ace, surprises everybody by barging into the lead, and he, Lawson and Owens run in feisty formation. Then Owens slices past both of his rivals with a bold move, and White falls back as his engine loses power.
Owens leads despite another gearbox problem. Lawson can’t take advantage because every time he buries the gas pedal, his engine stumbles. He resorts to feathering the throttle, which compromises acceleration and top-end speed, so he makes up for it by pushing harder in the corners. Racers often rate their effort in terms of tenths, with nine-tenths being an aggressive race pace and ten-tenths a banzai lap. As he and Owens scythe through lapped traffic, Lawson’s going eleven-tenths. At one point, he draws alongside the Brit, but Owens hangs tough, and Lawson can’t make the pass stick.
With two laps to go, Lawson’s kart runs out of gas and rolls to a stop at the end of the front straight. By this time, Payart is second, but he’s too far behind to challenge for the lead. Owens wins by 17 seconds. Back in the paddock, he’s hailed like a conquering hero. His father hands him a cellphone; his brother is calling from England to congratulate him. Owens pronounces himself well satisfied. “Eddie Lawson has never ever been beaten–until now,” he says.
Over in the Lawson pit, the atmosphere is surprisingly upbeat. Rainey is stoked after finishing fourth after a race full of slicing and dicing. And Lawson is pleased with his performance even though he’s disappointed by the result. “If I’d had a wide-open throttle, I think I would have had (Owens) covered,” he says. “After all, we were quickest through the whole weekend. Then again, if my aunt had balls, she’d be my uncle.”
Owens may be king for a day, but Lawson’s got nothing left to prove. He’s out here strictly for grins, and for a racer, life doesn’t get much better than Laguna Seca in a superkart. “Try one yourself,” he says, “and you’ll know what I mean.”
Preston Lerner, a contributing writer for Automobile, races his own Nissan 240SX in amateur events. He’s looking forward to his next chance to drive a superkart, as soon as his bruises heal.
Pitting the Superkart Against Rivals
Hail to the superkart! It leaves a standard sports car like the Mazda Miata in the dust, and even a muscle car like the Corvette, with its beefy hp and flashy top speed, is a pokey 25 seconds slower per lap. The superlight superkart (just 462 pounds) accelerates faster than the Corvette and is nimbler in the curves. The Champ car bests the kart, but there’s no shame in that: It costs 20 times more and requires an entire support crew.
Engine type: Turbo V8
Displacement: 2.65 liters
Peak power: 700 hp
Weight: 1,565 lb.
Lateral acceleration: 4 Gs
0-to-60: 2.2 seconds
Quarter mile: 10 seconds
Top speed: 240 mph
Lap time (2.38 miles): 1:10
Cost per second gained*: $11,500
Engine type: V8
Displacement: 5.7 liters
Peak power: 350 hp
Weight: 3,100 lb.
Lateral acceleration: 0.92 G
0-to-60: 4.8 seconds
Quarter mile: 13.2 seconds
Top speed: 175 mph
Lap time (2.38 miles): 1:50
Cost per second gained*: $2,500
Engine type: Two-stroke
Displacement: 0.25 liter
Peak power: 90 hp
Lateral acceleration:2 Gs
0-to-60: 4 seconds
Quarter mile:12 seconds
Top speed: 150 mph
Lap time (2.38 miles): 1:25
Cost per second gained*: $143
Engine type: Inline-4
Displacement: 1.8 liters
Peak power: 142 hp
Weight: 2,400 lb.
Lateral acceleration: 0.88 G
0-to-60: 8.1 seconds
Quarter mile: 16.3 seconds
Top speed: 121 mph
Lap time (2.38 miles): 2:00
Cost per second gained*: NA
Performance data for production models from Car and Driver. Some performance data for Champ car and superkart are estimates. *The additional amount of money driver must spend to gain each second on the racetrack, using the Miata as a baseline.
A BRUISED & DIZZY DRIVER
When Eddie Lawson told me his superkart was “a kick in the butt,” I didn’t think he meant it literally. My mistake. After driving it for 90 minutes, my body was dotted with ripe purple bruises–though I was having too much fun to notice. The only reason I called it quits was that all the lateral Gs I was pulling had my head flopping around like a newborn baby’s. Not to mention that I couldn’t focus my vision on the road in front of me–no small concern when you’re zipping along at better than 110 mph with your keister two inches from the pavement.
Lawson had generously arranged this test session at a racetrack carved from the Mojave Desert a few miles west of Edwards Air Force Base. The first order of business was to warm up the high-strung engines, which tend to explode if not romanced properly. Before long, the air was redolent with the aroma of burnt castor oil, which is mixed with 110-octane race gas to lubricate the internal moving parts of the two-stroke motors.
After Lawson turned a few shakedown laps, I squeezed into the formfitting seat. He gave me a push start; once rolling, I shoved the shift lever forward to engage first gear, goosed the gas pedal, and the kart scooted forward like something out of a Road Runner cartoon. After about, oh, two seconds, it was time to upshift. When I pulled the lever, second gear engaged with a satisfying thunk. Downshifting was easier still: I banged the lever forward and–voila!–no muss, no fuss, no clutch and no need to master the tricky racecar technique of heel-and-toeing to match engine and gearbox revs.
At low speed there was nothing to it. But when I nailed the throttle, I was like, “Holy horsepower, Batman!” Third gear, fourth gear, fifth, sixth and still pulling strong. I was too overwhelmed to scan the digital tach on the steering wheel, but I later realized that the power-band began around 8,000 rpm, and the screaming little engine didn’t run out of steam until closing in on 13,000 rpm.
Approaching a corner, I squeezed the brake and the superkart slowed so dramatically I lurched forward in my seat. Emboldened, I went deeper into the next turn and hammered the brakes. The rear wheels locked and the tail started to come around. No problem: I made a quick steering correction and the kart snapped smartly back into line. Soon I was sliding around like a stunt driver on a frozen lake. Nothing I’d ever driven responded so intuitively. There were no springs or shocks or complex aerodynamics to muddy the conversation: I felt a direct, almost telepathic connection between my nerve endings and the contact patch where tires met pavement.
Superkarts come with awkward baggage: Limited racing opportunities. Minimal sex appeal. Zero driver protection. They’re also hard on the wallet (by kart standards) and even harder on the body (by car standards). But short of spending hundreds of thousands, if not millions of dollars, a superkart is as close as most of us will come to the experience of driving a Formula 1 car. By the way, I was a full 12 seconds slower than Lawson. Talent, unfortunately, doesn’t come with the kart.
Photographs by John B. Carnett
Vision is generated by amplifying photons passing through the goggles’ lens.