When you read “plug-in hybrid,” you think of Volts, Prii, and the like. You don’t think about 900-hp supercars. Or didn't, as that's going to change thanks to the McLaren P1, which was unveiled at the 2013 Geneva Motor Show. Mclaren P1 Front Three Quarters We’ve known for some time now that the McLaren P1 would be as wildly powerful as it is wild-looking, but now we have the facts. Combined system output for the plug-in hybrid hypercar will be 903 hp and 664 lb-ft. According to McLaren, 727 hp and 531 lb-ft will be provided by a twin-turbo, 3.8-liter V-8, an upgraded version of the 12C’s engine running an additional 3 psi of boost. Additional thrust will be donated to the accelerative cause by a McLaren-built electric motor mounted to the back of the engine and producing up to 176 hp and 192 lb-ft. All that power is shunted to the rear wheels via a seven-speed dual-clutch transmission. All said and done, McLaren says the P1 will hit 62 mph in less than three seconds, 124 mph in less than seven seconds and 186 mph in less than 17 seconds (that’s 5 seconds faster than the McLaren F1). Its top speed is electronically limited to 217 mph, because, McLaren says, they’re after all-out street and track performance, not top speed. Power for the electric motor is provided by a 212-lb battery pack of unspecified chemistry mounted between the passenger and engine compartments, below the rear window. McLaren says it has the highest power density of any automotive battery on the market today. It will be charged by the engine, typically during coast-down, or can be plugged into the wall with a charger that stores in the luggage compartment. McLaren hasn’t revealed the battery’s capacity, but say it’s designed for rapid discharge, not maximum storage, and can be recharged from empty in just two hours when plugged in or 10 minutes in a special “pit lane charging” function. Pushing the “charge” button on the dash will also charge the battery from the gasoline motor, which tops it up in just 10 minutes. It does not use braking energy to recharge as McLaren wanted to maintain a natural brake pedal feel that hybrids just can’t achieve. Mclaren P1 Rear Three Quarter The electric motor does more than just make big numbers, though. The P1 will be able to drive on electric power alone “in excess of 10 kilometers,” or six miles, at up to 99 mph. McLaren also uses the electric motor to drag on the gasoline engine during upshifts to bring revs down more quickly and speed up shift times slightly. Conversely, the instant response of the electric motor means it can jump in at low RPM and increase throttle response while the big turbos spool up. Its party trick, though, is a “push-to-pass”-type feature called Instant Power Assist System (IPAS). Push a button on the steering wheel and IPAS dumps full battery power into the electric motor to deliver the full 176-hp boost. Unlike other hybrids, the P1 never switches back and forth between modes. The car runs in either full-electric mode or full-hybrid mode, so the gasoline engine will not be switching on and off behind you. It will, however, turn itself off at stop lights. There's another handy button on the steering wheel, one that activates the Drag Reduction System (DRS). Push it and the angle of the rear wing changes to reduce drag by 23 percent, allowing the car to reach higher speeds. Touch the brakes or release the button, and the system deactivates. The rear wing otherwise operates under computer guidance in concert with self-adjusting under-body flaps in the nose to stabilize the car and help create up to 1300 pounds of downforce. It also acts as an airbrake under hard braking. The computer continually adjusts the downforce and achieves its maximum at a more track-friendly 160 mph, bleeding off excess downforce at higher speeds so as not to overload the suspension.
Finally, the P1 features the hydro-pneumatic RaceActive Chassis Control system, which takes over much of the suspension duties. Traditional springs hold the car up, but a hydraulic anti-roll system and a pneumatic anti-squat and -dive system. Each wheel is controlled independently allowing for maximum ride comfort and handling, up to a claimed 2 g on the skid pad. Dampening rates are, of course, adaptive. It also acts as a vehicle lift system, to get you over speed bumps and the like, and lowers the car two inches in Race mode to create a ground effect under the car and suction it to the ground at high speeds. Brake Steer, meanwhile, brakes the inside wheels to pull the nose more sharply into the corner. The actual steering system is electro-hydraulic and changes depending on drive mode. Nearly half-a-turn of lock has been removed compared to the 12C, with full lock coming in just 2.2 revolutions of the steering wheel. Mclaren P1 Rear Side View The P1 operates in one of four driver-selected modes. Normal, Sport and Track each make incremental changes to the active damping, anti-roll, stability control, traction control and active aerodynamics systems. Ride height and dive/squat stiffness are unchanged. Set it to race mode and everything changes. Ride height drops, anti-roll and dive/squat stiffness ratchet up to maximum, and the rear wing extends to its maximum 11.8-inch height (4.7 inches is the maximum in other modes). The changes are extensive enough that it takes the car a full 40 seconds to enter Race mode. Of course, getting all that acceleration and handling under control require serious brakes, wheels, and tires. The brakes are designed specifically for the P1 by Akebono and feature a new carbon-ceramic composite never before used on a road car that’s been infused with silicon-carbide. McLaren says these brakes can absorb 50 percent more energy in each disc than the standard carbon-ceramic brakes on the 12C. The 15.4-inch front and 15.0-inch rear discs are clamped by six-piston front and four-piston rear aluminum monoblock calipers and can deliver nearly 2 g of stopping power. The wheels are likewise high-tech and made from a military grade aluminum alloy never before used on a street car. The 19-inch front and 20-inch rear wheels each weigh less than the 12C’s wheels and are wrapped in custom-made Pirelli PZero Corsas. Mclaren P1 Passenger Door Open The inside of the P1 is similar again to the 12C, but more extreme. Everything that can be made of carbon-fiber is and there’s no sound deadening at all. Carpeting is optional and there’s no extraneous trim or padding. Seat adjustments are all manual and some settings, like seat height, are tailored to the owner and can only be changed in the shop. To maximize aerodynamics, the occupants sit closer together than in a 12C and are angled one-degree outward to keep their weight as close to the center of the car as possible. The driver gets his information from three TFT screens in place of traditional gauges, a 6.8-inch central screen and two three-inch flanking screens. As you’d expect, the tach and speedo get priority, though in Race mode, it switches to a readout more akin to what you’d find in an actual racecar. The only thing the P1 doesn’t give you is a place for your luggage. A small compartment in the front is just big enough for two helmets and you can stuff a change of clothes in the netting behind the seats or in the door pockets. Don’t worry, though, you still get three cupholders. Assembly begins later this year and only 375 of the $1.15 million cars will be built.
