A man is beavering away in an Australian town near Melbourne, Victoria. His name is Jeff David, and for seven years he has been working on the so-called Quantum GP700. But this isn’t just any kit car. David has been building the first “hypercar” ever made in the country – and the outcome is astonishing.
The bustling town of Gisborne may seem a curious location for the development of a supercar. But it’s actually gaining something of a reputation as a “hipster” town. And it’s where David has his shed – the location for his company’s operations.
It’s fair to say that David is a car man; after all, he has more than three decades in the motoring business. He’s an electronics and automotive engineer – with a focus on developing engines and suspension valving. But it turns out that he’s not just an expert on tuning and building cars.
Interestingly, David – who also goes by the name JayDee – spent much of his early career working in the motorcycle sphere. But he has expertise that he can use in anything automotive. He works as an independent mechanic – installing traction control, logging data and analyzing it, re-valving shock absorbers and tuning dynos among other things.
In fact, David is the man for the more technical end of looking after cars. On top of his abilities as an automotive engineer, he has gained expertise as a fabricator in carbon fiber. He can also make components for the interior of different engines on a custom basis.
David has also spent a lot of time working with dirt bikes and in open-wheel racing and rallying. In his professional life, the engineer was employed in the car industry on the development of a telemetry system and an electronic control unit for engine management that could tune itself.
Apparently, David’s ability to fix motorbike suspension by re-valving it was considered legendary in competition circles. Many elite riders believed that he had an untouchable ability to keep motorcycles stable when moving rapidly. He also helped with the suspension of hundreds of bikes, and his understanding of suspension is what would eventually lead to choosing the base for his car that he did.
To this day, David’s company Quantum Performance Vehicles Pty. Ltd. still works on suspensions on dirt bikes – as well as on their engines. But much of the engineer’s work lies in the realm of cars. He tunes their engines with his own dynopack and analyzes logged data. And his hard work pays off; a car that he had tuned up took out its class at the 2018 Phillip Island Time Attack.
The car guru also works on his own products; he designs supercharger camshafts for the Honda K series on computer. Then, he fabricates them and makes them available for sale. This is on top of the work that he continues to do on his supercar – which, it turns out, is not the first souped-up auto that he’s created.
Previously, David had worked on what he called the “JayDee Atom.” This was a version of the Ariel Atom that he had used to learn more about developing a performance car. He told the website New Atlas in 2016, “As it progressed, the more I investigated each aspect. And as various difficulties arose, rather than being sensible and giving up on the process, those difficulties just made me more determined to overcome them and I continued onwards.”
Having experience with the vehicle, David decided to develop his own car on the base of an Ariel Atom. He told entertainment channel Barcroft TV in 2018, “I thought I’d start with the best car at the time, the best roadster I could buy, and that was an Ariel Atom.” This is a car developed by the Ariel Motor Company – a United Kingdom operation that licenses American maker TMI Autotech, Inc.
The Atom has worked its way through eight generations. The newest, the Ariel Atom 4, has a turbocharged engine with a capacity of two liters – or 122 cubic inches. It’s the same engine that is used in the Honda Civic Type R and has a three-stage boost. Indeed, that’s a long way from quite humble origins.
Niki Smart – then a student of transport design at Coventry University in the U.K. – received funding to develop what he called the Lightweight Sports Car at the school. And one of his lecturers acted as his finance guy. Meanwhile, in 1996 the car was ready for showing at the British International Motor Show.
David saw the car as perfect to use as a development base. He explained to Barcroft TV, “So I bought one and dismantled it and then started modifying it. I progressively altered the engine, the chassis, the driveshaft and the brakes to improve the performance.” However, just improving the Atom didn’t satisfy the engineer.
David’s dream was instead to create his own supercar, and he began a seven-year quest to do exactly that. He began making his Quantum car piece by piece. Inspired by the front wing on a Formula 3 car, he built his own wing by hand. He told Barcroft TV, “I shaved it to keep a really narrow front nose.”
For the car’s paneling, the engineer created his own carbon-fiber mix. He identified a problem with plain carbon fiber: its propensity to shatter. So, after experimenting with Kevlar and aramid – a synthetic polymer used in bulletproofing – he came up with his own material to mold the car’s bodywork out of.
One of David’s aims was that the car would be legal to drive on Australian roads – so the wheels and tires were semi-sleeks that would be allowed. He created his own steering wheel for guiding the automobile. But the biggest job would be the engine, and this required several different iterations before he was satisfied.
However, the existing engine in the Atom was nowhere near powerful enough for the engineer. David told Barcroft TV, “The overall result has been a progressive increase in power from 300 brake horsepower – where we started – to just under 700 horsepower now.” The engineer seemed quietly thrilled by that, as he added, “It’s probably the highest-powered supercharged engine in the world.”
Something that was really important to David – given his aim of being “road legal” – was driver comfort. As he designed the car, he focused on ensuring that it would be a comfortable drive. Years of development of suspension came in useful, as he incorporated his designs into the shock absorbers. The result is a smooth ride even on Australia’s sometimes rough roads.
The work that David put in was incredible – so much so that his wife had to step in. Apparently, she ended up placing the car designer under a curfew. He would be up at 5:30 a.m. to tinker with the car, but he had to finish up by seven in the evening. However, even his beau couldn’t stop him from working every day of the week.
In return, David’s wife was willing to support the family financially. And it’s just as well, because the engineer spent $300,000 on parts for the car. The mechanic said to Barcroft TV, “She gave me a two-year deadline. So I was able to work full time for two years uninterrupted to try and get the car finished.”
In the end, David claimed that had poured about 1,800 hours into the Quantum. But the engineer had no aim of recouping his money or being rewarded for all that work. He wouldn’t sell the original Quantum; but if the car did catch the eye of someone with a decent slice of money to spend, he could make another model.
David told Barcroft TV, “The Quantum is a culmination of my life-long dream to build a super car.” In the metric measures familiar to Australians, the car had a ratio of power to weight of one to one. This makes it about doubly as powerful as a Lamborghini Aventador and a hair less rapid than a Formula 1 car.
If you like to get going quickly, the Quantum is the motor vehicle for you. It can get from zero to 60 miles-per-hour in less than three seconds. Although its speed is restricted, it’s still seriously rapid and can reach 174 miles per hour. Furthermore, its design allows it to take corners at 112 mph without pushing G too high.
On the track, the Quantum’s an astonishing ride. The power-to-weight ratio is 60 percent more than you’d get with the somewhat comparable Bugatti Veyron SS. And the specially designed aerodynamics provide 1G of force that keeps the wheels securely on the road – which helps allow that thrilling cornering ability.
But surely that power on the rear wheels and the car’s light weight will mean oversteering is a constant problem? It turns out that it isn’t, because the Quantum GP700 has something called predictive traction control. This system actually monitors your style of driving so that it can keep the highest amount of power flowing to the wheels safely.
However, anyone who finds the idea of roaring with 700 horsepower booting the car around can tone it down. And the power can be shifted down to 300 if the driver feels the need. The traction control can be turned down, too – allowing the car to drift if the driver wants it to.
The transmission on the car was specifically developed to provide for upshifting that only takes two-hundedths of a second. If the driver wants, gear shifting can also be entirely automatic – allowing the car’s occupant to keep their focus on where they’re going. On the road, though, the car uses a clutch like any other stick shift.
The immense power of the Quantum, meanwhile, comes from its engine. This is a four-cylinder affair with a capacity of 2.7 liters or 165 cubic inches. But David did not just pop a Honda engine into his car and hope for the best. No, this was the focus of many changes aimed at perfecting the power provision.
Most engines with forced injection have superchargers in parallel, but the Quantum has its two in series. This allows the achievement of greater pressure than you can get normally. But it doesn’t have the turbo charger’s lag, so the boost is smooth and powerful. And the engine burns through six liters – or 1.5 gallons – of fuel each minute.
Complex systems manage the engine as well as controlling traction. The latter is aided by the body – which is designed to create enough downforce to hold the car on the road or track. However, even with the powerful push down on the car, it doesn’t suffer from drag. This is thanks to the efficient design of the body.
The Quantum’s chassis has a tubular design, and it’s made out of aluminum good enough to build an airplane out of – carbon fiber and Kevlar. This keeps the chassis extremely stable when the car is moving quickly but doesn’t make it hard to handle when it’s being driven a little more sedately.
The suspension is actuated by push rods and has anti-roll bars at the front. It can be tuned so that it suits the driver, and in keeping with David’s philosophy, it’s valved so that it performs at its best. A position displacement suspension system works alongside the suspension to keep the grip consistent and predictable.
Even given the spareness of the exterior, there’s still room for comfort inside. The seats are David’s own design made out of carbon, and you strap into them with three-inch harness seatbelts. The dash displays readouts from the car’s many sensors – overlaid with mapping by GPS. These data can be studied after driving, and while moving they help to inform the systems that control the car.
The bodywork – representing the end of many years of simulation on the computer – has been designed to shift air over the cockpit. This allows both the driver and any passenger to be enclosed in static air. Given the open cockpit, the driver can see well, and the stillness prevents wind from blinding them.
The body also works along with the cooling systems – pushing air into intakes that allow it access to the engine. This is necessary because when it’s operating at full, the engine will need more than 7,000 gallons of air every minute. If that sounds a lot, then yes, it is. You breathe about that much in a bit more than two days, according to the Quantum GP700 website.
In 2015 the car had taken a form that meant it could be shown off and get publicity. And there was plenty of talk about it being sold. Perhaps because of its name – the GP700 – the figure of $700,000 was mentioned. However, that figure was purely a guesstimate, and the car has never had wider production.
And David’s work continues at the time of writing. He has molds that could be used to create a new model’s body panels. He also has jigs for the chassis and suspension and even a spare collection of chassis tubes. So, he hasn’t given up hope that he’ll be called on to build a second GP700 – and in less than 1,800 hours this time.
But even if David never sold a single car, he was more than happy with what he had made. He told Barcroft TV, “I just love the look of the car. The way it’s turned out with the handling, the performance, the acceleration. Every aspect of the car, I really enjoy it, and I really love it.”
And what’s the Quantum like to ride in? Which Car? journalist Louis Cordony shared his view in 2015. He wrote, “[David] finds the throttle and then it happens. There’s an explosion of brutal speed and sound that launches an attack on you so visceral, it’s as if your ribcage closes like a bear trap, the acceleration so instant and unrelenting your organs squeeze.”