Outrunning Gravity: How Battery Boost Mode Made the FF91 a Hero

Faraday Future
7 min readJun 12, 2017


As our FF 91 prototype vehicle glides up to the starting line, its presence makes an unmistakable impact. It’s almost wraith-like, with nearly silent motors and a black camouflage exterior that drinks in the desert sun.

It’s in stark contrast to its competitors: a Ferrari 488 GTB supercar, a Bentley Bentayga SUV, and a Tesla Model X P100D, coined by its maker to be “the safest, fastest, and most capable sport utility vehicle in history.” Perhaps no car seems a greater juxtaposition than the sporty Tesla Model S P100D — claimed “the quickest production car in the world.”

Next to them, our prototype feels like a dramatic silhouette brought to life — almost melding into the shadows cast by these industry titans that it’s soon to race against.

As the countdown for the 0–60 MPH powertrain test begins, it seems like this is the moment our prototype car was built from the ground up for (barring its aftermarket wheels and tires chosen for testing purposes). However, this sense of predestination couldn’t be further from the truth.


Our FF 91 production vehicle was always designed to have a competitive presence in the luxury performance segment, with the goal of featuring an assertive degree of acceleration — early targets for our 0–60 time were around 4 seconds.

Peter Savagian, VP of Propulsion Engineering, realized that there was still potential for improvement. After all, the large capacity battery system, patented electric inverter, and robust software offered a remarkable amount of flexibility. Plus, our prototypes’ multi-motor configuration provided all the raw muscle required.

Tools ready. We just needed to figure out how best to leverage them.

Savagian sought to achieve a 0–60 MPH time in the illustrious sub-3 second realm. Lead propulsion engineers Silva Hiti, Steven Schulz, and Phil Weicker helped spearhead this undertaking. They put their heads together and formed a special engineering team to find a solution — but this endeavor was a formidable one.

They had to shave a full second off the vehicle’s acceleration benchmark, while contending with the limited time and resources that a startup environment — and the preexisting and ever-growing duties associated with the launch of a global automaker — already imposed. On top of all of this, they had only a few months to do so — but that was no deterrent.

“It was unifying. It felt like a challenge, not a chore,” Savagian remembers. They threw everything they had at the problem. “We set out to destroy our own parts through intensified performance…this effort accelerated testing and subjected our components to entire lifespans worth of wear and tear. It gave us an indispensable insight into how the vehicle was functioning as a holistic system over time…and it felt way more heroic than just walking around and asking ‘hey, how’s that half-shaft holding up?’”

After weeks of tweaking hard parts and testing at closed course venues, eventually the answer revealed itself. It wasn’t a traditional hardware issue they needed to solve — it was a software one.

They cracked the code. They created something they called “Battery Boost Mode.”


Battery Boost Mode is an FF-patented software that can scale the exchange of current between the battery, the motor, and the electric inverter at will.

During a normal drive, our inverter’s semiconductor switches rapidly change position, shifting modes upwards of 10,000 times a second. This results in a stable flow of energy — and a smooth, reliable ride.

Each time a semiconductor switch shifts position, there is a conductive loss that causes a discharge of heat. This temperature needs to stay within an acceptable bound to ensure system reliability — and when trying to accelerate the vehicle, there is a strict upper bound to how much heat it can responsibly withstand.

However, if you decrease the frequency of these switch shifts — from 10,000 times a second to only 3,000 — the discharged energy is no longer a restrictive issue. The temperature can be maintained much more easily, and indefinitely.

This change results in two immediately noticeable differences:

  1. The normal, hover-smooth drive is traded for a much more powerful, intense one.
  2. You accelerate faster. A lot faster.

Overall, Battery Boost Mode provides 20% more battery current, 25% more motor current, and 10% more torque than in normal drive mode.

“This is all made possible with our FF Echelon Inverter,” explains FF Technical Fellow, Steven Shultz. “It has a level of flexibility that I’ve never seen before. The more I work with this hardware, the more I fall in love with it…and we’ve only tapped a fraction of its potential.”

After this innovation was discovered, its algorithms refined, and its design patented, there was only one thing left to do: put it to the test. Fast forward a few weeks later to our head-to-head 0–60 MPH test at the Irwindale Speedway.


  • Bentley Bentayga: Bentley’s ultra-luxury sports utility vehicle, declared to be the “fastest production SUV in the world.”
  • Ferrari 488 GTB: Ferrari’s latest infamous 8-cylinder sports car and Top Gear’s 2015 Supercar of the Year.
  • Tesla Model X P100D: Tesla’s flagship electric sports utility vehicle, fully-featured and charged.
  • Tesla Model S P100D: Tesla’s flagship electric sports sedan, fully-featured and charged.
  • FF 91 Prototype: Faraday Future’s powertrain development prototype, built in-house — sans aftermarket wheels and tires — to test the limits of acceleration.


We held our 0–60 MPH benchmark vehicle test at Southern California’s Irwindale Speedway, known as the “fastest drag strip in the West.” A former NASCAR arena and a current crucible for underground racers, this was the perfect place to push the limits of our prototype.


We data-logged performance of each vehicle with RACELOGIC’s VBOX 3i, a top-of-the-line velocity data-logger widely utilized by leading automotive manufactures and premiere media. This model costs over 80x the price of an average data-logger, but that expense begets an indisputable degree of accuracy. The integrated GPS/GLONASS receiver can log precise location coordinates 100 times a second, putting this tech in a metrological league of its own.


0–60 MPH Results: FF 91 Prototype Vehicle — 2.39 sec., Tesla Model S P100D — 2.50 sec., Tesla Model X P100D — 2.90 sec., Ferrari 488 GTB — 3.00 sec., Bentley Bentayga — 4.00 sec.
0–60 MPH time as stated by manufacture, 11.21.16

It was a blowout. Buttoned-up vice presidents were screaming and senior engineers were literally jumping with joy. These results prove that we have something special on our hands: a potent powertrain with the ability to accelerate with supercar quickness. We aren’t simply competing in the luxury performance segment anymore — this means we have the potential to redefine it. It’s a true testament to the potential of electric powertrains and the engineering prowess of Faraday Future’s Los Angeles R&D team.

“Our test results gauge our acceleration speed at 1.1g, meaning that our vehicle can literally outrun gravity.”

Moreover, this degree of acceleration means that our prototype doesn’t simply outrun our competitors. If you drop an object from a tall building, it will accelerate at a rate of “1g” — or 9.8 meters per second squared. Our test results gauge an acceleration rate of 1.1g, meaning that our vehicle can literally outrun gravity.

“To say the car ‘moves quickly’ is an extreme understatement,” laughs Test Driver and Lead Powertrain Engineer, Brian Harries. “Electric vehicles are known to accelerate fast, but they usually top out pretty quick and the acceleration plateaus. But this car, it just keeps going and going and going…like its acceleration will never end.”

“It was incredible to experience everything we’ve been working toward so tangibly, so viscerally,” he smiles, “and any day you have the opportunity to blow the doors off a benchmark Ferrari is a pretty good day.”

You could say our engineers can best whatever forces they’re up against — even ones of nature.


“The fact that this improvement is possible on the same key hardware [battery, motors, inverter, powertrain, etc.] shows that we can pursue all kinds of performance enhancements — in essence — for free,” Shultz elates. “This greatly expands the scope of the advances that we can offer through over-the-air updates. This will make for a car that will truly get better with time.”

“This was only made possible by the extraordinary teams and dauntless working environment we have here at Faraday Future,” Savagian muses. “We have permission to fail. To dare to fail. Pursuing this 0–60 time felt like a pipedream in the beginning…but look where we are now. We may break a few parts along the way, but this degree of courage — this degree of audacity in the face of setbacks and discouragements — allows for amazing things to happen.”

Amazing things like a vehicle that can outclass its competitors, outperform naysayers’ expectations, and even outrun gravity. And this is only the beginning.



Faraday Future

Faraday Future is a global intelligent mobility ecosystem company