On the Juice: Relearning performance lingo for the electric era.
;I took two semesters of physics in college. The first concerned the physical world – objects smashing into one another, mass, momentum – concepts that made intuitive sense. I got a B. The second focused on electromagnetic fields, which are invisible and have something to do with calculus.
I got a D+. So it’s perhaps understandable that I’m a bit apprehensive about the brave new world of the electric car.
After more than a century of dominance, the internal-combustion engine is the reference point for our gearhead sensibilities. I can have a conversation about throttling losses and crankcase windage – granted, it’ll be a very boring conversation, but I’ll know what I’m talking about. Electric motors, though, are a mystery, a bundle of strange unknowable calculus. What is the electric equivalent of, say, a turbocharger? Or a four-valve combustion chamber? Or a supercharged, direct-injected V-8? I called Andrew Farah, chief engineer for the Chevrolet Volt, to try to glean some electric knowledge.
“It’s a new way of looking at it, but it’s all the same stuff,” Farah says. “There’s a prime mover, it’s got a power rating, and you’ve got to get the power to the wheels.” OK, so we’ll always have horsepower and 0-to-60-mph times. That’s comforting. But the specifics are where I get confused. Pistons smashing up and down due to fiery explosions from dead-dinosaur juice – that I can understand. Electrons are a bit more beyond my ken.
For example, I used to mess around with car stereos. In the aftermarket stereo world, Rockford Fosgate amplifiers are renowned for their ability to handle crazy loads. Some guy would have a two-channel Rockford amp rated at 15 watts that was somehow running twenty subwoofers and causing permanent hearing damage two counties away. He’d say, “Well, it’s 15 watts at 4 ohms, but I’ve got this sucker running a sixteenth of an ohm, so now it’s pushing 5000 watts.” That’s like saying, “Well, my Nissan Versa’s got 107 hp, but now that I’m towing this motorhome, it’s putting out 450 horses.” And somehow, in the electric world, it makes sense.
I ask Farah how the hot-rodders of the future will hop up their electric cars. I want to know what to point at and admire when someone pops the hood – “Oh, I see your BMW ActiveE has the Dinan Stage 1 large-gauge power cable. Sweet!” Farah thinks that software tweaks will be prevalent (as they are now), but the hardware is still so new as to defy significant improvement. “Manufacturers are the ones hopping up the electric car,” he says. “You’re already getting this thing that’s hopped up to the point that we’re breaking stuff. A year ago, I was breaking the crap out of motor mounts. We couldn’t make them any bigger.” General Motors solved the motor-mount issue, but the implication is that there isn’t a lot of performance left on the table. “I’m not sure where I’d go with it,” he says. “The Volt’s not a 1972 Camaro.” True. The only lithium in a ’72 Camaro would’ve been found in the driver’s bloodstream.
I keep pressing, and eventually Farah concedes that would-be electric tuners might swap out their power controllers, if they accepted the risk of smoking their motors. OK, power controllers . . . now what are those?
To learn more, I called my friend Dave. He has several radio-controlled cars, one of which is electric and does about 60 mph. I ask him about electric powertrains, and Dave launches into a five-minute primer on the performance nuances of electrics – at least, those at one-tenth scale. “You can have different winds on the motor, depending on what you want,” he says. “A five-wind motor would have more top-end power but less torque, than, say, a seventeen-wind. On a brushless motor, you can change the timing and the relative position of the rotor. Advance the timing and it’ll be faster, but the motor won’t last as long and you might overheat it. And you can have a sensored or unsensored motor. A sensored motor knows the orientation of the rotor, so it doesn’t cog.” Oh, I hate cogging my five-wind brushless sensored motor . . . right?
Besides the motor itself, there’s the power-control electronics and the battery. All three of these components can be tweaked for more speed. I still don’t understand the specifics, but it sounds like electron junkies of the near future will find themselves in a position familiar to today’s tuners – trying to find that fine line between extra power and total meltdown. And that, I can understand.
Written By: Ezra Dyer
Illustrated By: Tim Marrs