RSS Feeds
Drag Racing Goes Electric
By using hundreds of pounds of batteries and "slamming" massive amounts of electrical current into their drive motors, drag racers are enabling small electric vehicles to beat gasoline-powered Corvettes and Vipers
Charles J. Murray, Senior Technical Editor -- Design News, May 25, 2009
Scroll down to view the Drag Racing Goes Electric slideshow!
Roderick Wilde's cars are so powerful, they've done wheel stands. They've snapped axles. And, in drag races, they've "blown the doors off" 450-HP Dodge Vipers.
"If we went much faster, we would've made those Vipers look like they weren't moving," brags Wilde, a long-time racing enthusiast. "Those drivers might as well have thrown open their doors and walked."
If Wilde were just another speed-obsessed gear-head, his exploits might be little more than local legend. But Wilde isn't just another speed-obsessed racer. He's a speed-obsessed electric racer. And in the world of drag racing, as well as in the greater automotive universe, that makes his achievements special.
To be sure, Wilde's newsworthy exploits aren't unique. The
National
Electric Drag Racing Association
(NEDRA) now counts about 100 members who've raced in Oregon, Michigan, Arizona, Florida, Washington D.C., and even England. Among them, there's much fashionably muscular talk of blowing doors off, putting hammers down, sucking amps, and slamming electrical current into motors. The racers' have cars with names like Maniac Mazda, Crazyhorse Pinto and White Zombie. But amidst all the loud, zealous banter, there's also speed. Lots of it.
"You get these guys who are driving their gasoline-powered Corvettes, Mustangs, and Audis, and they're losing on the drag strip to electric cars," says Mike Willmon, an engineer who also serves as the president of NEDRA. "It's opening up some eyes."
Indeed, heads are turning. A racer named John "Plasma
Boy" Wayland, designer of the White Zombie, has pushed his street-legal electric Datsun to an extraordinary 11.4-second quarter-mile. Willmon, meanwhile, has covered a quarter-mile in 12.4 seconds in his electric 1978 "Crazyhorse" Pinto. And Bill Dubé, founder of the so-called
KillaCycle
team, owns an electric motorcycle that covers a quarter-mile in a stunning 7.82 seconds, reaching speeds of 168 mph.
What's more, the engineering behind the vehicles is impressive, not only in terms of power development, but in the way the owners have created technologies on shoestring budgets. Thanks to the efforts of the electric racing community, there's now a motor controller capable of parsing out huge voltages and currents to the vehicles' drive motors. There's also a battery controller that enables them to charge their huge battery packs without damaging them.
Racers say that such new technologies are enabling them to do amazing things. "Rod raced against a GM EV1 awhile back and beat it with his backyard-built Mazda," says Wayland of his one-time competitor,
Roderick
Wilde. "The guys from GM were shocked. Here they had a million-dollar prototype with AC drives, and along comes this long-haired guy from Washington who blows their doors off."
A New Image
It wasn't always so, however. A little more than a decade ago, virtually all racers considered electric vehicles to be glorified golf carts. That began changing in 1994, however, when the
Oregon Electric
Vehicle Association
decided to stage an electric drag race to show the public that environmentally-acceptable EVs could be "fun and exciting." The organization cordoned off a little street in downtown Portland, grabbed a few stop watches, and laid chalk lines on the cobblestone surface.
Wayland, however, was not about to stand for the idea of a genteel, 30-mph drag race. He found the concept offensive; it was as if someone had tried to paint a smiley face on his soul. "I thought about the 72-volt cars that could barely get out of their own way, lumbering and wheezing uphill at 30 miles per hour," Wayland recalls. "And I said, ‘We can't show this to the public.'"
He didn't. Wayland used a helicopter battery and transformed his Datsun 1200 into a 175-volt race car. "They weren't expecting cars like mine," he says now. "Here I came with my Datsun, burning rubber in all five gears and smoking the tires. Women and children were running for cover."
Then Wilde showed up. Wilde, who now runs a Washington-based electric vehicle parts company (evparts.com), unloaded his electric Mazda from the back of a trailer, smoked his tires for 200 feet, and did a "wheel stand" (in which the vehicle rears up on its hind wheels like a horse).
From that moment forward, the image of electric vehicles forever changed. And the ensuing years have reinforced the new image. The ultimate proof of this lies on the Internet. Dubé points out that an advanced Google search for his Killacycle yields hits in virtually any imaginable language - Icelandic, Latvian, Norwegian and even Esperanto. Moreover, specials by
Oregon Public Broadcasting, and the Discovery Channel have immortalized the electric sport - at least within the tight drag racing community - reportedly drawing as many as a million viewers to their websites to watch the videos.
No one who knows racing, it seems, is unaware of the sudden advancement of electrics. When Wayland drives his White Zombie onto a drag strip, crowds form. "The car is like a magnet," he says. "People are shocked when they hear we've done this with a Datsun."
Electric Torque
Indeed, the vehicles of the electric drag racing world are shocking, in more ways than one. Starting in the early 1990s, backyard mechanics began converting their gas-powered cars to pure electrics, ripping out the gas tanks and rear seats, replacing them with batteries, and then re-configuring the powertrains. (Go to Wilde's company web site for
conversion directions.) When the drag racers burst onto the scene, however, the number of batteries and the associated voltage skyrocketed.
"Back in the ‘90s, the typical EV that someone built in their backyard was 72 V or 96 V," Wayland says. "That was the norm, and 120 V was the new high-voltage standard."
It didn't take long for the racers to realize, though, that those voltages were just too low and too slow. Over time, the numbers soared to 336 V, 360 V and 380 V. Willmon, for example, employs two parallel strings of 30 batteries in his electric 1978 Pinto. The batteries, lead-acid
Hawker
Odyssey
units from
Enersys,
Inc., reside in the back seat, as well as in the vacated spot where the Pinto's
infamous
gas tank
used to be. They amount to 848 pounds of mass, equally distributed across the rear (drive) axle. With the two strings, Willmon's system creates about 360 V and 1,600 A of current, theoretically generating about 576,000 W (0.576 MW) of power.
"It's all about the battery," notes Dubé. "The technology in the rest of the machine is interesting, but the battery is the key."
Still, the racing vehicles can't accelerate quickly without a drive motor that produces prodigious amounts of torque for low cost. In the world of electric drag racing, most owners favor brush-type DC motors, combined with healthy amounts of innovation. Willmon, for example, uses two 9-inch diameter brush-type DCs mounted back-to-back. In essence, the motors are the same type used for electric forklifts, with modifications. He ordered them from
NetGain Motors,
Inc., an EV motor distributor that worked with the manufacturer,
Warfield
Electric Co., to beef up the shaft, bearings and brush materials, thus preparing the motors for the demanding environment of the drag strip. Once he had the motors, Willmon hard-coupled them together with a stock gear coupler and joined them to the driveshaft through a splined output and a yoke assembly.
The result of this arrangement is surprisingly practical for a racer, since there's no need to install a heavy and costly transmission. On a dynamometer, the Pinto's powertrain typically generates 314 HP across the full-range from 0 to 5,000 rpm, and yields an astounding 1,500 ft-lb of torque at 0 rpm.
"A gas engine has to ramp up to reach peak torque and power," Willmon says. "But with an electric motor, when you put current through it, it generates torque immediately."
Monster Power
None of that can happen, however, if the current from the battery isn't used properly, and that's where the electronic control comes in. Many racers now use a product developed by
Café Electric
LLC, a firm that specializes in making EV motor controllers.
Café Electric's product, known as the
Zilla
(named for Godzilla), is a favorite among racers because it's programmable. Programmability enables Zilla to vary the input and output - essentially trading current for voltage and vice versa. It can, for example, take in a large voltage and small current from the battery, and then produce the opposite at the motor.
Racers are enamored with the Zilla because it's all about power. In a green box (it's the same color as Godzilla) a little bigger than a loaf of bread, the Zilla can control upwards of a half-megawatt of power, they say.
"You can program the Zilla for ungodly motor current," notes Wayland. "So you can nail it off the line and protect your battery and only pull, say, 800 A or 900 A out of your battery. But then you can slam 2,000 A into the motor."
To reach really high speeds, however, all of the racers know they are at the mercy of battery manufacturers. In that respect, electric drag racing development is no different than conventional electric car development.
That's why elite racers hold hopes of securing lithium-ion batteries for their vehicles. Lithium-ion, which has already established itself in the development of GM's Chevy Volt, is already being used in Dubé's Killacycle, and could see more widespread use by this summer.
Dubé says his ability to obtain the highly powerful and expensive lithium-ion batteries has hinged on his knowledge of the emerging technology. He currently uses 550 lithium-ion ion cells from
A123
Systems, a well-known manufacturer of batteries for the electric vehicle market. The cells, arranged in five strings of 110 batteries each, provide "far more" power density than standard lead-acid batteries, but neither Dubé nor A123 will say how much more.
To date, A123 has been careful about providing the costly lithium-ion cells to racing teams, but Dubé has been successful because of his team's development of a battery management system that helps keep the voltages of the individual cells within prescribed boundaries. Dubé's battery pack, which produces about 375 V, uses hundreds of the controllers. "We said to A123, ‘We won't damage your cells,'" Dubé explains. "We know how to care for batteries."
The technology developed by Dubé's team is unassuming: a tiny circuit board, about the size of two postage stamps, containing a shunt regulator and a light-emitting diode (LED). The shunt regulator serves as a sensor.
When the battery is charged near capacity, the system senses it and lights a green LED. When it reaches full capacity, a red light turns on. To stop the flow of current, Dubé manually turns a knob. He facetiously refers to the system as an opto-biomechanical technology, in which the LED is the "opto," the knob is the "mechanical," and Dubé himself is the "bio."
Hope Springs Eternal
Other race teams are hoping to use A123's lithium-ion technology, too, largely because it provides more power density than lead-acid batteries. Moreover, a new generation of A123's technology is expected to offer more horsepower at less than half the weight, enabling Dubé to cut as much as 100 pounds from his motorcycle and -- hopefully -- enabling bigger vehicles to cut even more weight. Most race teams, however, aren't expecting to receive demonstration batteries from A123, nor can they afford to buy the costly new batteries themselves.
Still, there's hope. "If I get the lithium pack that I want, the White Zombie will turn a 10.85-second quarter-mile, and you can take that to the bank," Wayland predicts.
Whatever happens, Wayland is ready. Last year, he had the dubious distinction of being thrown off a track for breaking 11.5 seconds in the quarter-mile without a roll cage or fire suit, and it has buoyed his spirits since. "It's a badge of honor," he explains. "Everybody wants that moment where you get kicked off the track."
Having been successfully dismissed, Wayland and others are planning to lower their times this summer - with or without the "hot shot" new lithium-ion batteries. At the
Wayland Invitational
at Portland International Raceway on July 24-25, they're expecting eight new Tesla electric vehicles, along with Dubé's Killacycle, Willmon's Crazyhorse Pinto, and Wayland's own White Zombie.
"I would be happy with a 10.999," Wayland says hopefully. "I just want to have the first street-legal electric car to make it to the 10's."
Gallery »
Drag Racing Goes Electric
