A few weeks ago, Holley’s MotorLife blog covered an electric vehicle doing something we typically associate with combustion: dragsters.
What Fans Love About Top Fuel Dragsters
While most normal drag racing cars start their life as a factory car of some kind and then duke it out against the competition for quarters and eighths of miles, the most wild drag racing machines are custom built. Some add a normal car body on top to look like a car, while the most extreme machines make no pretenses of being anything but a custom rig that prioritizes acceleration above everything.
Everything about Top Fuel dragsters is a caricature of automotive technology, and then a caricature of that. They’re powered by the most potent of alcohol-nitromethane fuels, and this potent mixture gets burnt by engines that are built from the ground up to perform amazingly for only a few seconds (they’d melt down if run for more than ten seconds). They often have no liquid cooling systems (something some EVs sort of get away with, but that’s very rare in today’s combustion vehicles), a sacrifice made for strength and rigidity. They otherwise tend to use relatively primitive pushrod, two-valve engine technology, but still make insane levels of power using a supercharger.
When they take off, they produce so much torque that they twist the tires into a smaller overall diameter from hub to tread, temporarily giving the vehicle a lower gear ratio and a much larger contact patch. As they speed up (reaching 100 MPH in 0.8 seconds), the tires expand again and give the vehicle a more favorable gear ratio for speed. But all of that power comes at a cost. After every race, the whole engine needs to be overhauled. And, that’s assuming they don’t blow up during their run, because the best racers are always at the edge of exploding. They’re that insane.
Even the exhaust pipes push out so much exhaust that they themselves push the car down and forward just from the pressure of those escaping gases.
For fans, it’s a sight to behold. The primal sound, the fastest accelerating cars on the planet, and everything else about the race is truly a spectacle of racing, automotive engineering, and a show that impresses our inner caveman, whether the car makes it to the end of the track, goes up in flames, violently explodes, or goes airborne and disintegrates from all of the force.
Enter The Electric Dragster
If you’re a fan of EVs, you’ve probably been thinking to yourself, “Hey, this is an ideal job for EVs! They have lots of torque!” And, you’re definitely right. That’s why racing gear companies have been working behind the scenes with racing teams to get electric vehicle technology onto the track.
In 2016, veteran racer Steve Huff saw an interview on TV with earlier legend Don Garlits, who was the first racer to hit 200 MPH in a Top Fuel car back in the 1960s (today’s Top Fuel dragsters are going over 300). The topic? The race to do the same in an electric dragster. “I’m not really an electric car guy — I love internal combustion engines — but ICE tech has fundamentally stayed the same for more than a century.” Huff told MotorLife. “I was inspired by that interview with Don, but what really stuck out to me was that he said he didn’t think 200 mph was possible with the technology that was currently available at that time. That’s when I decided to design and build a car to break that barrier, and we named it Current Technology.”
When he first heard that other racers were trying to break the 200 MPH barrier on electric power, he looked into what they were doing. Unlike Tesla and other modern EVs, these pioneers were still messing around with DC motors instead of an inverter and AC power (which still has to come from DC batteries). To give them a run for their money, he had to spend a lot of his own:
“A DC motor will provide massive amounts of power for a very short amount of time, and it’s relatively inexpensive compared to an AC drive system,” he explained to MotorLife. “An AC drive system is more complex — we essentially had to double the weight in order to make comparable power, and by doubling the weight, we had to make even more power on top of that to compensate for the extra pounds. And because it involves inverters, newer motor tech, and more motors, the costs quickly start to add up with AC drive systems. But the advantage is that AC systems are much more tunable, more consistent from a performance standpoint, and our setup should be basically maintenance-free for more than a decade. There’s a reason why all of the OEMs are going the AC route now.”
This AC vs DC competition, reminiscent of the Tesla vs. Edison days, propelled both teams to 180 MPH in 2017, but getting either technology up to 200 was an elusive challenge, even for these well-funded teams. The technological arms race continued, with the teams besting each other by just 1-2 miles per hour, slowly climbing from 180 to 186 MPH.
What finally propelled Huff’s team past the goal was an improved motor controller and data logger that finally enabled them to gain fine enough control over the AC motor to get maximum performance in a drag car. On May 7, 2020, they finally broke 200 MPH. Further tuning took them to 202.52 MPH, the overall electric drag record, earlier this year. His competition hasn’t broken that speed record, but they’re making their way through the quarter mile a bit faster than him.
Now, his goal is to fine-tune the dragster and push for a 6-second quarter mile, so there’s a lot of development work ahead:
“Without a clutch in it, our car runs a 1.35 second 60-foot time. For a 200 mph drag car, that’s dreadfully slow. But we’ve developed a new clutch system for the car, and we’ll be testing it in the coming weeks. We are the first team to utilize a clutch in an EV dragster like this, and that allows us to compensate for all of the low-end power that a DC motor would make. AC motors don’t have that — it’s a common misconception that it’s instantaneous full torque. If this clutch does what we’re expecting it to do, it should allow us to be the first in the 6s.”
This latest version of the electric drag car uses a custom lithium-ion battery pack that puts out 1.6 megawatts of power, but that’s not enough to stay ahead of the rest of the industry forever. With racing sanctioning bodies opening up electric divisions for drag racing and other teams jumping into the fray, there’s going to be some exciting years ahead.
Will fans accept quieter racing vehicles that don’t blow up as often? I think they will. Huff and Garlits are already going to go on a racing tour this year, and fans want to see them in action.
Featured image by Holley.