Anyone still on the fence about electric cars needs to open their eyes to the fact that we’re living in the best possible automotive age. At the very same time, we get to witness peak internal combustion, from highly efficient turbocharged commuter cars to the new C8 Chevrolet Corvette Z06’s screaming V8 engine. But Elon Musk also made sure to jumpstart the EV industry by making his Teslas just as fun as ICE cars—not to mention much faster than anything even close to comparable—rather than simply utilitarian and eco-conscious.
An entire cottage industry of electric drivetrain swaps lurks over the horizon, as well, which will help keep classics on the road while allowing for ungodly acceleration. Those powertrain swaps do present more complexity than most YouTube videos might reveal, however, from obvious issues like battery and wiring placement to important details including temperature regulation and daily drivability considerations.
Having driven all the Teslas and a fair share of other EVs, I found myself curious to learn how some of these aftermarket electric swaps actually drive, so I reached out to a local company called AEM EV hoping for a chance to hop behind the wheel of their Tesla-swapped Ford Mustang nicknamed the “Testang.”
Introducing The “Testang”
I first spotted the Testang back in December of last year at Autopia 2099, an enthusiast EV and EV swap meet that brought an impressive range of bone-stock cars and custom builds in various stages of completion to Optimist Studios in Los Angeles. At Autopia 2099, I noticed a number of project cars running AEM’s screens and since then, the company seemingly pops up everywhere I look—from the Volkswagen ID.4 Baja racer that Tanner Foust piloted through the desert to a TA2 car I checked out at Radford Racing School, even all the way to a home-built electric motorcycle I watched charging on the back of a Rivian pickup truck. Luckily, AEM’s Director of Marketing and Public Relations Lawson Mollica gave me a quick tour of the Testang at Autopia 2099 and invited me to check out AEM’s facilities in nearby Hawthorne where I could learn more and drive the converted 2007 Ford.
Burning Rubber Easily
While the Testang looks relatively stock from more than 20 feet away, little cues to AEM’s electric conversion begin to crop up with each step closer. A few stickers read “High Voltage” and show off the Tesla logo, while a bunch of tar and rubber caked onto the quarter-panel behind the rear wheels proves how easily this souped-up Mustang can shred tires. Another quick hint comes when comparing the brakes fore and aft, since the front calipers read Wilwood while clamping down on drilled rotors and the rears wear Tesla badging with solid discs.
A Clean Battery Bay
When Mollica pops the Testang’s hood, a clean wiring job surrounding batteries, drive accessories, and AEM’s control units occupies the space formerly known as an engine bay. Long gone are the stock 4.6-liter V8, which would have been good for 300 horsepower and 320 lb-ft of torque when new, as well as the five-speed stick shift through which power the rear wheels originally received power. Arguably, though, the Testang’s engine bay looks better now—as a piece of rolling advertisement that also serves as a testbed for AEM’s hardware and software testing, aesthetics remain just as important as functionality. But Mollica told me the Testang moniker actually applies more to the drive unit, since AEM found while testing various battery options that those used by hybrid cars actually offer the higher levels of immediate performance potential that this build requires, as opposed to the longer range made possible by Tesla’s cells.
Tesla Drive Unit And Subframe
Up front, AEM’s BMS (Battery Management System), PDU-8 (Power Distribution Unit), and VCU200 (Vehicle Control Unit) simultaneously control and monitor the swapped-in power cells and the ‘Stang’s original power steering pump, brake booster, and even headlights. In the trunk, AEM installed a clear floor to reveal the base Tesla drive unit, plus another PDU-8 controlling contactors, relays, and the large finned onboard charger visible to the left, above. (Fun note: that orange shade for the wire housings actually has its own official Pantone color.) The motor itself still sits in a Tesla rear subframe—complete with the original axles, hubs, and brakes—but modified with AEM’s Inverter Control Board that allows users to control the unit and create custom torque maps.
Keeping The Testang Lightweight
One major concern for EV manufacturers involves the tradeoff between weight and range—at the moment, even the Evija that Lotus claims will be the lightest, most powerful electric hypercar on the planet will weigh around 3,700 pounds. The Testang tips the scales just below that figure, or only slightly more than the stock Mustang GT’s 3,356-pound curb weight.
Pulling out of AEM’s parking lot, I immediately noticed the instantaneously available torque made possible by electric power, though I focused more on driving dynamics than all-out acceleration. After all, just about any EV on the market today provides plenty of grunt for city life—sometimes even too much. And as Mollica walked me through the Testang’s features, my mind kept clicking back to how little I needed to stay cognizant of throttle modulation, braking pressure, or steering input. The prospect of excessive body lean or oversteer due to swinging around too much weight never even entered my mind throughout our half-hour drive.
AEM’s EV-Swap Hardware & Software
Mollica started me off in what he called “Granny Mode” for the Testang, to demonstrate AEM’s ability to map out various levels of throttle response starting at a peak of 300 Nm (or 221 lb-ft) of torque. But keep in mind that my right foot could easily access every single bit of that figure at any time, plus as Mollica explained it, the Testang employs a final drive that essentially results in a nine-times force multiplier.
The little AEM dash behind the steering wheel showed a surprising amount of information clearly, though the sizing seems derived from AEM’s history in motorsport and could use a few more inches of height and width for everyday driving. Flipping through various pre-programmed and customizable screens revealed gauges for remaining range, state of charge, brake regeneration, individual battery conditions, and, of course, current speed. An eight-key button pad on the center console replaces the Mustang’s traditional shifter and allows for the selection of Park, Drive, Neutral, and Reverse, as well as turning on the electrical contactors, traction control settings, and power levels. An additional customizable button allows users to choose any other parameters for their home project that they might desire.
Bumping up to 450 Nm of torque (or 331 lb-ft times nine, again) transforms the Testang from a solid sprinter into an all-out ripper. Mashing the accelerator pedal (we can’t really call it a throttle anymore, right?) produces exactly the kinds of spine-adjusting G forces everyone loves about electric vehicles today.
Drag Times And Autocross
Mollica can drive the Testang to and from AEM headquarters and his house on a single charge—or about 70 miles. AEM kept that figure obviously short of even a base Tesla Model 3’s range to keep weight down and prioritize organization over cramming literal tons more of battery cells into the Mustang chassis. Mollica claims the build now runs a full two seconds faster than the stock Mustang in a quarter-mile (which seems like an underestimate to me) and he even told me about some autocross plans coming up soon.
Reducing the amount of sound deadening and insulation to help show off AEM’s installation and wiring job does result in a fairly noisy ride, especially on the freeway, serving as a reminder for how much EV manufacturers and backyard builders alike need to focus on NVH (noise, vibration, and harshness) reductions without an internal-combustion engine to cover up any creaks, rattles, wind, or tire roar. But in terms of creature comforts, once AEM gets the air conditioning system working (it’s partially installed currently), the overall experience will take another little notch up, since Mustang’s steering wheel and seats actually feel quite nice already.
All told, the Testang as it sits now, somewhere between experimental prototype and high-performance advertisement, definitely provides an impressive inkling of all the software and hardware that today’s burgeoning electric enthusiast community wants and needs to perform the swaps of their dreams. And yes, the Testang can definitely smoke those rear Hankooks with just as much ease as any Hoonigan fan might consider necessary.
Sources: aemev.com, autopia2099.com, radfordracingschool.com, and hoonigan.com.
Read Next
About The Author
