The results of a unique hydrogen powertrain technology concept feasibility study conducted by British Briggs Automotive Company (BAC) and Viritech to develop a new e-Mono have been released.
The Office for Zero Emission Vehicles awarded Viritech a Niche Vehicle Network Feasibility Study grant to conduct research into developing a hydrogen powertrain for niche vehicle applications. The e-Mono concept was developed in collaboration with Liverpool-based BAC, makers of the renowned Mono supercar. It follows BAC’s principles of uncompromising performance and driver experience.
One of the most difficult aspects of converting a 555kg Mono supercar to zero-emissions is maintaining its ultra-lightweight, especially since going battery-electric would make the car 50% heavier. Furthermore, while BEV cars can travel at the same speed as a gasoline-powered counterpart, the joy of a track-focused supercar lies in its agility and responsiveness through corners. Viritech and BAC set out to design a ZEV (Zero Emission Vehicle) e-Mono that adhered to BAC’s founding principle of making the best-driving car in the world.
Viritech’s philosophy is to create fuel cell drivetrains that are lighter, smaller, and more efficient than anything else on the market, and BAC wanted to create a ZEV powertrain that could be fitted into the existing chassis and body while minimizing weight. The e-Mono also needed to match, if not better, the Mono R’s Silverstone lap time.
The combination of a fuel cell, a hydrogen storage tank, and a battery pack would be heavier than a gasoline engine, but if kept to a manageable weight, the Mono’s legendary agility would not be compromised.
Fitting a fuel cell powertrain into an existing Mono chassis was one of the biggest challenges, followed by maintaining perfect weight distribution and finally fitting the finished car into the confines of existing Mono bodywork.
Battery pack
The solution was to cram the battery pack element as far under the seat as possible, and by making the battery pack casing a structural component, the chassis footprint was reduced, allowing more space to be used. The fuel cell was then installed above the battery pack, with the compressor hidden inside the air intake pod used for the Mono R’s petrol engine.
The result is a battery pack that produces 265 horsepower, a fuel cell that produces 107 horsepower, and tiny 3kg front-wheel motors that provide an additional 55 horsepower per motor and all-wheel drive.
In a series of Digital Twin simulation tests, the e-Mono was able to shave two seconds off the Mono R Silverstone lap time (2.04.3 vs 2.06.3). The fuel cell and battery combination allowed the car to complete 10 fast laps of Silverstone before refueling. On the official WLTP cycle, on-road range is calculated at 166 miles, but in real-world use, it’s closer to 140 miles.
Meeting performance
By 2024, improvements in fuel cell efficiency will enable a 50 percent increase in range without increasing powertrain size or weight.
The Mono-powertrain R’s weighs only 212kg, while the e-additional Mono’s weight of 149kg includes the new all-wheel-drive system. However, there is room for weight savings by using a carbon case for the fuel cell, which would save an estimated 15-20kg, and Viritech is working on a new battery module that would save another 30kg. The overall vehicle weight would be within 100kg of the current Mono-R.
In the virtual world, a fuel cell electric powertrain has been shown to meet the performance requirements of the world’s most driver-focused, lightweight supercar. They can also be met without modifying the vehicle’s ultra-compact footprint or bodyshell.
The findings of the joint feasibility study provide BAC with a solid foundation and basis for a future proof of concept project, which it will continue to develop and improve with its technical partners in preparation for launching e-Mono to the world.
