The secrets of the Speedtail

McLaren’s Hybrid Hyper-GT

May 1, 2020

Motorsport technology, the world’s most powerful electric motor in a production car and intelligent high voltage energy storage

– along with proven V8 muscle – make the streamlined Speedtail a McLaren, and a hyper-GT, like no other.

McLaren Speedtail Dynamic Track Rear

The McLaren Speedtail’s unbelievable maximum 403km/h speed might look like the stuff of science fiction on paper.

But behind that phenomenal stat (confirmed during the hyper-GT’s high-speed validation testing in the United States recently), a combination of advanced engineering aspects all contributes to making the Speedtail McLaren’s fastest hybrid performance car

The Speedtail has been purpose designed to embody absolute aerodynamic excellence and low vehicle weight. Fundamental to the hybrid-GT’s astonishing performance is a race-bred electric drive system that incorporates pioneering battery technology to set a new benchmark for hybridised efficiency. This unlocks the Speedtail’s intense acceleration from standstill to 300km/h in just 13 seconds.

The M840TQ powertrain comprises a twin turbo 4.0-litre V8 engine and an electric drive unit, which together develop up to 1,070PS (787kW) and maximum torque of 1,150Nm. The engine features technology that has evolved from McLaren’s first hybrid hypercar, the legendary McLaren P1. A new lightweight air-intake system, improved cylinder head cooling and a revised piston design contribute 757PS (556kW) and 800Nm of ‘traditional’ petrol-powered output to the Speedtail.

The electric motor, which uses Formula E-derived technology, generates more than 230kW. It gives the Speedtail the highest performance installation ‒ including cooling and integration ‒ of any electric motor currently in use on a production road car. Power delivery is 8.3kW/kg, which is twice the efficiency of an average sports car.

Engineers from McLaren Applied ‒ the McLaren Group division that focuses on virtual product development, telemetry, electrification and control ‒ worked with the Speedtail Electric Drive Technology team to integrate its ground-breaking motorsport-developed inverter and DC/DC converter technology into the electric drive system, ensuring the levels of control and power management required for the hybrid Hyper-GT to realise its extraordinary performance.

The high voltage energy storage system is where the Speedtail is truly innovative. A high-power cylindrical cell arranged in a unique array, the 1.647kWh unit is at the cutting edge of battery technology, being extremely compact and delivering the best power-to-weight ratio of any high voltage battery available today.

As an indication of how McLaren technology has advanced, the power density of the Speedtail’s advanced battery is four times that of the unit in the McLaren P1.

McLaren Speedtail Static Three-quarter

The design and integration of the battery system enables the Speedtail to achieve its maximum speed by intelligent energy deployment, with these headline figures achievable because the cells are thermally controlled by a ‘dielectrical’ cooling system and permanently immersed in a lightweight, electrically insulative oil which quickly transfers heat away from the cells.

This system – the first of its kind in a production road car – is highly efficient and allows the cells to run harder and for longer.

In all, the McLaren Speedtail hybrid hyper-GT represents the melding of science fiction and science fact.

Words by Cameron Officer