McMurtry Spéirling
The McMurtry Spéirling is an electric single-seat prototype sports car which was first presented at the Goodwood Festival of Speed in 2021. The car is developed by McMurtry Automotive, a British registered startup founded on 2 June 2016 by Sir David McMurtry. "Spéirling" is Irish for "thunderstorm".
A distinguishing feature of the car is its use of "active downforce", achieved through integrated fans that generate suction to increase grip, even while stationary. This system provides a significant advantage at low speeds. Demonstrations have shown the car operating on an inverted rotating platform, indicating that the generated downforce can exceed the vehicle's weight. Similar fan-based systems had previously been used in motor racing during the 1970s but were later banned.
History
According to McMurtry, the motivation behind the car was to challenge the industry trend of increasingly heavier vehicles and, by using first principles design, create a lightweight electric driver's car. The prototype car is the first step to demonstrate what customers will experience on road and track. It is not currently in a racing series but is built to satisfy relevant motorsport safety requirements, with crash structures and a carbon-fibre monocoque chassis with integral rollover protection. Its unique performance differentiator is the fan-powered downforce system, producing of downforce at a standstill.The car, developed in secrecy over three years, was first presented at the Goodwood Festival of Speed on 8 July 2021, and driven by Derek Bell.
In December 2022, it set the following times verified by independent GPS timing without rollout by Mat Watson from carwow on Silverstone:
- 0- in 1.55 seconds
- 0- in 2.63 seconds
- 0- in 4.98 seconds
- in 7.97 seconds
Specifications
Below are the specifications for the Spéirling PURE:- Peak power output:
- Top speed:
- 0- in 1.55 seconds
- in 7.97 seconds
- Weight:
- Battery capacity: 60 kWh
- Rear wheel drive
The car has rear-wheel drive using two electric motors placed inside a specially designed "e-axle", and uses carbon brakes. The monocoque has room for a driver tall. The battery is integrated into a separate safety cell inside the monocoque.
Active downforce
A special design aspect of the car is its active downforce system without the use of large splitters or wings, by means of twin fans which provide an extra of downforce from a standstill. This allows the car to corner at a G-force of more than 3g. When the fans are at full speed, they emit about 120 dB of noise.The use of fans powered by separate motors to provide downforce was first conceived of by Jim Hall for the Chaparral 2J, a Can-Am car he designed, constructed and raced in 1970. However, the 2J was banned at the end of the 1970 Can-Am series. A downforce fan system was also used in the Brabham BT46B Formula One car, which was designed by Gordon Murray. It won its only race, the 1978 Swedish Grand Prix, before the car was withdrawn from racing by Brabham and the technology was banned for the following season.