McLaren P1: 903 bhp plus 664 lb-ft equals outrageous acceleration

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It wasn’t so long ago we were gasping at the absurdity of the Bugatti Veyron’s 1,000+ bhp, but that tips the scales at some 2 tonnes and requires its own oil refinery to run. McLaren’s P1 weighs nearly half the Veyron and can run (briefly) emissions free, thanks to its 176bhp electric motor.

Based on a substantially revised version of the 12C’s 3.8-litre twin-turbo V8 petrol engine combined with an electric motor, the P1 offers a combined output of 903 bhp (916PS) and maximum torque of 664 lb-ft (900Nm). The engine block is made from a unique casting to incorporate the electric motor, while the unit has been upgraded to optimise cooling and durability under higher loads.

McLaren are quoting emissions of less than 200g/km on the combined cycle, which would point towards an average fuel consumption of somewhere in the mid-40s mpg.

The instant response of the 260Nm (192lb-ft) electric motor, developed in-house by McLaren Electronics, provides a sharper throttle response, and the enhanced air-charging system provides the P1 with more top-end power. One further benefit of the electric motor is being able to provide faster upshifts. This is achieved 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.

The electric motor is mounted directly onto the engine, and all drive is channelled through the dual-clutch seven-speed gearbox to drive the rear wheels. Thus, the electric motor and 3.8-litre twin-turbo V8 petrol engine work seamlessly together, providing more than just added ultimate power and torque.

  • McLaren P1 Powertrain G2 McLaren P1: 903 bhp plus 664 lb ft equals outrageous acceleration
  • McLaren P1 Powertrain G1 McLaren P1: 903 bhp plus 664 lb ft equals outrageous acceleration

The petrol engine produces 727bhp at 7,500rpm and 531lb-ft (720Nm) of torque from 4,000rpm.

Other tricks up the P1’s sleeve include the new E-mode option, which enables more than 10km of driving solely powered by its 176bhp electric motor – ideal for most city journeys. When the battery is empty, the petrol engine will automatically start to maintain drive and charge the battery.

Drivers can also use the EV powerplant to deliver Instant Power Assist System (IPAS) – a 176bhp hit of extra acceleration, which comes in handy for acceleration.. if the twin-turbo V8’s 727bhp proves insufficient on its own.

The P1 is fitted with an innovative lightweight battery pack (just 96kg), which makes all this possible, and is mounted on the underside of the P1’s carbon fibre chassis. It can be fully charged in two hours using a plug-in charger that can be stored in the car’s luggage compartment.

We were anticipating some sort of KERS (Kinetic Energy Recovery System) to be fitted in the P1, and McLaren describe its function as operating off-throttle when the electric motor provides additional drag torque. Energy is then recovered to the battery which would otherwise be lost (as heat) to the brakes.

The innovation continues with the P1’s dynamic prowess, as in Formula 1 the P1 is fitted with a Drag Reduction System (DRS) which adjusts the angle of the wing to reduced drag by up to 23 per cent. The system immediately deactivates when the button is released, or if the driver touches the brake pedal.

McLaren P1 Powertrain G3 999x665 McLaren P1: 903 bhp plus 664 lb ft equals outrageous acceleration

The DRS and IPAS systems are operated via two steering wheel-mounted buttons, allowing the driver to maintain focus on the (fast approaching) road ahead at all times.

McLaren have yet to share any performance figures for the P1, but 916bhp in a car weighing less than an Exige S is bound to get your attention. If you thought the Veyron was unbeatable, prepare to have that notion blown apart.

More news in a fortnight’s time.