McLaren M838T engine

The McLaren M838T engine is a 3.8 litre 90 degree twin-turbocharged flat-plane V8, designed and developed by in collaboration with Ricardo plc.

== Development == McLaren bought the rights to the Tom Walkinshaw Racing-developed engine (based on the Nissan VRH engine) which was designed for the IRL Indycar championship but never raced. However, other than the 93 mm bore, little of that engine remains in the M838T.

Developed with help from Ricardo with technology acquired from Menard Competition Technologies, it is McLaren's first engine. The engine redlines at 8500 rpm, however 80% of the engine's torque is available as low as 2000 rpm. McLaren claims that the engine has the highest horsepower to CO2emission ratio of any current production engine.

The engine is built at Ricardo's engine assembly facility in Shoreham-by-Sea,West Sussex. The turbochargers are supplied by MHI, and are different units from those used in Mitsubishi Lancer Evolutions.

Applications
The engine was designed and built for the McLaren MP4-12C supercar, where it produces 592 horsepower and 466 ft·lbf of torque. However, in 2012 McLaren released an update increasing power to 616 horsepower. For the GT3 racecar, the engine produces less power at only 493 hp.

McLaren and Ricardo redeveloped the M838T engine for use in the McLaren P1. The engine has been upgraded to optimise cooling and durability under higher loads. The engine block has also been modified to incorporate an integrated electric motor as part of a hybrid drive train. The petrol engine produces 727 horsepower at 7,200 RPM with an additional 176 horsepower from the electric motor. At 4,000 RPM the engine is said to produce 720 Nm of torque while the electric motor can produce a maximum of 260 Nm from 0 RPM upwards.