A figure like 900hp satisfies the supercar buyer but the tree huggers should be pleased to hear McLaren has adopted electric power to boost the V8 biturbo in the new P1 model.
It will combine two efficient powerplants: a mid-mounted 3.8-liter twin-turbo V8 and an electric motor mounted directly onto the engine. They will give a combined output of 903hp and maximum torque of nearly 700 lb-ft!
The combination will also yield instantaneous throttle response through the rev range while only producing emissions of less than 200g/km on the combined cycle, reduced to zero emissions in full electric mode.
The 3.8-liter V8 biturbo is a new version of the M838T unit in the MP4 12C. To reach these astronomical numbers, the lightweight electric motor produces 176hp and maximum torque of 190 lb-ft from idle. The instant reactions of the electric motor provides a sharper throttle response associated with normally aspirated engines, while the enhanced air intake system enables the McLaren P1 to have more top-end power.
The power is channeled through the dual-clutch seven-speed transmission to drive the rear wheels. Additionally, the e-motor can provide faster up-shifts. This is achieved through the application of instant negative torque at the point of shift, making the engine revs drop as quickly as possible to the required engine speed for the up-shift.
The McLaren P1 can be driven in a variety of modes, powered by the engine and electric motor together, or solely by the electric motor. This allows use in low emission zones and residential driving is optimized with near-silent running. In E-mode, the P1 can travel more than six miles on electric power, which should be enough for most city journeys. When the battery is empty, the V8 will automatically maintain drive and charge the battery.
Through two steering wheel-mounted buttons the pilot can choose to activate the DRS (Drag Reduction System) and IPAS (Instant Power Assist System). The DRS is similar to that employed on F1 cars so that as speed increases, drag is reduced on the rear wing and, where the MP4-12C has a moveable flap on the wing, the P1 can alter its angle by 23%.
The system deactivates when the button is released, or if the driver touches the brake pedal.
The Instant Power Assist System is designed to deliver power for high performance acceleration, and provides 179hp before the turbos start boosting the V8.
When developing IPAS a groundbreaking, lightweight battery pack was developed. It uses a combination of high-power cells, low weight and an innovative cooling system.
The battery weighs just 211 lb and is mounted to the underbody of the F1-grade carbon fiber MonoCage chassis.
Producing power brings immense heat, so a complex cooling system was required, with coolant flow balanced so each cell is cooled to the same temperature.
Further details of the McLaren P1 will be released ahead of its world debut at the Geneva Auto Show in March.