McLaren reveals performance of P1 powertrain

20 February 2013
By Edward Gent
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The P1's combination of a V8 petrol engine and an electric motor give a combined output of 903 bhp

The P1's combination of a V8 petrol engine and an electric motor give a combined output of 903 bhp

A diagram detailing the inner workings of McLaren's P1

A diagram detailing the inner workings of McLaren's P1

The McLaren P1's 3.8-litre twin-turbo V8 petrol engine

The McLaren P1's 3.8-litre twin-turbo V8 petrol engine


McLaren’s latest supercar, the P1, will produce 903bhp and emit less than 200g/km of CO2 thanks to its hybrid powertrain.

The firm today revealed details of the car’s twin power system which combines a mid-mounted 3.8-litre twin-turbo V8 petrol engine with an electric motor giving a combined output of 903 bhp and a maximum torque figure of 900Nm.

The petrol engine is a new version of the familiar M838T unit, that has been significantly upgraded to optimise cooling and durability under the higher loads and produces 727 bhp at 7,500rpm, and 720Nm of torque from 4,000rpm.

The lightweight electric motor, developed by the McLaren Electronics arm of the group, is mounted directly onto the engine and all drive is channelled through the dual-clutch seven-speed gearbox to drive the rear wheels. It produces maximum torque of 260Nm instantly from a standstill, increasing the throttle response of the car.

Additionally emissions of less than 200g/km on the combined cycle are reduced to zero in full electric drive mode, which has a range of more than 10km – enough for most city journeys. When the battery is empty, the petrol engine will automatically start to maintain drive and charge the battery.

The e-motor also provides faster upshifts through the application of instant negative torque at the point of shift, making the engine revs drop as quickly and efficiently as possible to the required engine speed for the upshift.

And the power available via the petrol engine and electric motor is further enhanced on the McLaren P1™ through two steering wheel-mounted buttons which activate the Formula 1-derived DRS (Drag Reduction System) and IPAS (Instant Power Assist System).

With the DRS, speed is increased by reducing the amount of drag on the rear wing and, where the MP4-28 has a moveable flap on the rear wing, the McLaren P1™ has a wing that reduces in angle to lower drag by 23 per cent. The system immediately deactivates when the button is released, or if the driver touches the brake pedal.

IPAS is designed to deliver power rapidly for high-performance acceleration, and provides 179PS of instant additional power. In developing the IPAS technology for the McLaren P1, power delivery was prioritised over energy storage using a lightweight battery pack, which McLaren claims offers greater power density than any other automotive battery pack on sale today.

The high power density has been achieved through a combination of high power cells, low pack weight and an innovative cooling system. The battery weighs just 96kg, and is mounted onto the underbody of the high-strength Formula 1-grade carbon fibre MonoCage chassis, which seals the unit in the vehicle, thus avoiding the added weight of any unnecessary battery packaging.

Due to the amount of power being supplied by the battery, complex cooling is required to guarantee cell performance and reliability. The coolant flow is balanced so each cell is cooled to the same temperature across the entire pack.

In addition to the battery being charged via the engine, the McLaren P1™ is also equipped with a plug-in charger, which can recharge the battery from empty in only two hours.

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