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Advanced Engine Management’s origins date back to the late 1980s when the company first opened its doors in Compton, California. Originally a tuning and fabrication shop, AEM began developing its own products a few years later, initially focusing on performance components like cold air intakes and big brake kits before its breakthrough Wideband UEGO gauge kick-started a new segment of the industry.
By 2009 AEM had shifted more of its focus toward electronics, developing new engine management systems, CAN-based sensor systems, and other associated product lines to help racers and enthusiasts extract all of the available performance from their combinations. And as evidenced by their latest development mule, the Testang, that mission continues today.
“We cut our teeth in EV development working with Ford Performance on the Cobra Jet 1400 and helping Huff Motorsports with their dragster which, with the help of our VCU, was the first EV dragster to hit 200 MPH,” explains AEM’s Lawson Mollica. “So, for us, EV development really started on the racing side.”
With the knowledge and testing experience gained from those programs, AEM looked to the Tesla Large Drive Unit as the next platform for development, but they were missing a not-insignificant piece of the puzzle. “We were at the point where we had done all of the bench and dyno validation on the Base Drive unit, but we needed something to put it in,” he recalls. “So we needed a development vehicle, and we also needed a Sport Drive for validation on that unit as well.”
As luck would have it, AEM’s EV application engineering manager Nathan Stewart was scouring Craigslist one day and happened to find an ideal candidate. “He was looking for a Sport Drive and found this car, which happened to have a Sport Drive in it already,” Mollica tells us. “So it was perfect for this – we could bring it in, rewire it with all of our electronics and clean up whatever we needed to along the way. And honestly, for a garage build this was done really well. Mechanically and fabrication-wise, this guy did a really nice job. We wanted to get on-road validation of our VCU, PDU-8, battery management system, and everything else, so this fit the bill perfectly.”
The team at AEM bought the Tesla-swapped 2007 Ford Mustang GT and wasted no time getting it into their shop. But before yanking out the Sport Drive system and wiring in their electronics, they decided to get some benchmark numbers. Although the Tesla Sport Drive is factory rated at 600 Nm (roughly 443 lb-ft torque), with the open-source aftermarket control circuit board that was being used to control it, the car actually made 525 Nm (387 lb-ft torque) on AEM’s chassis dyno.
The Testang came into the shop outfitted with two parallel strings of air-cooled batteries for a total of 30 kWh (16 cells per module, two parallel strings of 6 modules in series; 12 total modules). On Tesla swaps it is necessary to use the modules in parallel – even the Base LDU draws over 1000 amps, and a single battery string will not support the amp draw. Although running parallel strings is not necessarily ideal for this type of application, AEM felt that the setup was suited for the task.
The team soon set to work with the goal of making the Testang not only perform better, but also more drivable. “The original builder fabricated brackets to accept the Tesla subframe, so when we installed the drive unit, we bolted in most of the assembly – the half shafts, the hubs, the brakes – almost all of it,” Mollica notes. “And because the S197 is narrower than a Model S, we needed a pretty aggressively offset wheel to push the bowl back in. We found those characteristics in the factory wheels from a 2008 Corvette, but those are a temporary solution – we’ll be swapping those out for a set of custom Finspeed F10s in the coming months.” AEM also equipped the Testang with a set of QA1 coil-overs for more suspension adjustability, and a Wilwood big brake kit is onboard up front to bolster the car’s stopping power.
Along the way the team also swapped out the Sport Drive unit for a Base Drive unit paired up with AEM’s Inverter Control Board, the latter of which allows the Tesla inverter to be managed by AEM’s programmable VCU200 vehicle control unit. After also installing AEM’s battery management system for field validation and rewiring everything with sealed connectors and sheathing, the team then mounted up a CD-5L digital dash and data logger as well as AEM’s CAN Keypad. The keypad provides touchscreen functionality for traditional “gear” selection (P,R,N,D,L), programmable power modes, activation and deactivation of the high-voltage system, and the traction control functions that are currently in development. The car was also outfitted with two of AEM’s PDU-8 expansion modules that allow the VCU to handle switched functions for the cooling systems, electrically-assisted power steering, power inverter, and other electronically-controlled components over CAN bus.
“Like a lot of custom builds that we’ve seen over the years, there were a few elements that were kind of missing,” Mollica says. “So we wanted to integrate features that would give you OE-system control, information, and safety. This project wasn’t about making a weekend car, or something you’d take to the car show and tuck it back into the garage until next time. We want hot rods like this to be something that you can turn into your daily driver. And that’s really what our testing has evolved into here.”
Although testing is on-going, the numbers already bear out the potential performance benefits of a swap like this. While a factory-stock ’07 Mustang GT proved to be good for a 13.6 second quarter mile at 102 MPH in AEM’s testing, the Testang has already laid down an 11.78 at 117 MPH. “The ability to dial in the torque map is a big deal,” Mollica points out. “It basically takes the car from a full-sized RC car to something that feels like it came off of a dealer showroom.”
And more upgrades are on the way. Along with the aforementioned Finspeed wheels, the Testang is slated to score Sparco racing seats and an AC system with real adjustability. “The air conditioning in EV conversions typically isn’t very good,” he says. “It’s hard to figure out how to get it to run well – it’s either full-on or full off for both heating and cooling. But we can give you real air conditioning – you can actually put in an AC compressor and run it at variable speeds with actual temperature inputs, etc.”
Ultimately the Testang project is less about shock and awe and more about showcasing where things are headed. “It’s a hot rod, and it does hot rod stuff,” Mollica quips. “It’s about building what you’re passionate about and then going out and enjoying it. Taking it up the coast, or to the autocross, or to the drag strip. That’s really the purpose of this car – to show what’s possible.”