It was hard to imagine a world where a single DeltaWing existed, but having watched the Nissan-powered brainchild of Ben Bowlby turn its first laps at California's Buttonwillow circuit in March of 2012, the funny little prototype soon became a regular part of the sports car landscape.
After making its debut last year at Le Mans, the car continued under the ownership of ALMS founder Don Panoz, returning this season with a new, Mazda-based powerplant. And with the planned competition debut for DeltaWing's closed-top car next week at Circuit of The Americas, the manufacturer's first bespoke design will make its public debut at the penultimate ALMS round.
In an interesting bit of timing, Bowlby could also see his newest design, the Nissan ZEOD – a brand-new closed-top evolution of his DeltaWing – turn its first laps in the UK before the end of the month. Two different companies targeting the same sports car audience, similar product timing with skinny-front-tire, emissions-friendly coupe prototypes…it's easy to get the origins for each vehicle confused.
RACER spoke with Bowlby ahead of Nissan's first shakedown of the Zero Emission On Demand concept to clarify if and what lineage the ZEOD shares with the DeltaWing, starting with the carbon fiber tub.
“The ZEOD is a new chassis built from scratch, and designed to the 2014 LMP1 regulations,” said Bowlby. “It's a completely conventional sports car, two-seater, off-center seating, has the latest Zylon anti-intrusion panels, and is genuinely a conventional spec carbon tub. The external surfaces of the tub are touched by the airstream, whereas the Aston Martin tub used on the [DeltaWing] required bodywork mounted to form much of the chassis' surface.
“So that's very positive development for the ZEOD. The weight is very low. It's been optimized for low positions – having the driver's seat down on the ground, where we don't need to put them in the high-nose style or anything like that. It's a carefully optimized modern chassis.”
Like other leading-edge prototypes, the ZEOD tub has produced as a single piece instead of the more familiar routine of bonding the top and bottom halves together to form the chassis.
“The tooling is multi-piece, but the chassis is made in one piece,” Bowlby continued. “It's a right-hand-drive car, which is optimum for Le Mans with changing drivers and all the rest of it. It's completely standard, and in fact for the 2014 regulations the driver has to be offset from the center-line of the car, so all of those guidelines have been followed.”
The ZEOD will continue to use Nissan's small four-cylinder turbo, but the entire exercise for the Japanese marque is focused on developing a suitable electric propulsion system. Bowlby's chassis, as one would expect, has been designed to accommodate a large volume of battery storage and discharge technology within the cabin.
“The monocoque has been laid out to accommodate 120 kg of battery, which gives us the 12 kWh of electrical energy,” the Briton explained. “The positioning of the battery is, if you like, traditional for the energy store, so it's behind the driver seat back. Obviously, the range of the car is assisted by gasoline, conventional gasoline liquid fuel. And that fuel cell nests with the battery behind the driver seat back. It's a lot of stuff fit into a limited volume, but that's part of the fun in bringing the ZEOD together.”
Some of the innovations that made the DeltaWing so visually unique have appeared in the initial ZEOD concept and could be retained when the final version of the car runs in anger. Bowlby also explained how some new design elements have been carried out in relation to the hybrid system.
“The whole of the aero shape of the tub is in order to complement the underbody and so on, where in Garage 56 we don't have to use the underbody shape of the regulation LMP1 style,” he said. “And we've optimized the aero for the underbody performance and it basically made the battery accessible from below. So you take the battery out by removing the floor region underneath the battery, which is all structurally mounted on to the car.
“We have to perform crash tests with battery on-board and so on. So there's a lot of extra load and very dense mass in the back of the car that is part of the crash test. It's accurate to say that the creation of the ZEOD chassis has been done with every aspect of FIA compliance in mind.
“It's all very new to use in some ways and there's lots to think about. All the guys designing for the ZEOD project have had to think about lots of different requirements from an electrical standpoint, particularly. Everybody has had to learn about the electrical side of the concept, and about how to best design an electric racing car for the first time in their careers. It's been a major, major undertaking.”