The technical revolution of 2014 can be expressed in one simple phrase: the engine is no more, long live the Power Unit!
The idea of the engine as a standalone source of propulsion in Formula One was consigned to history several years ago through the introduction of KERS Hybrid power in 2009 and from 2011 through 2013. That said, the change for 2014 is altogether more far-reaching.
Out go the 2.4 litre, normally aspirated V8 power plants used over the past eight years. In comes a 1.6 litre, turbocharged V6 configuration with integrated Hybrid Energy Recovery System (ERS) to form the Power Unit. Each driver will be limited to a maximum of five Power Units per championship; three fewer than the allocation of eight last year.
In regulatory terms, the Power Unit comprises six different systems: the Internal Combustion Engine (ICE), Motor Generator Unit-Kinetic (MGU-K), Motor Generator Unit-Heat (MGU-H), Energy Store (ES), Turbocharger and the Control Electronics. The change in terminology reflects the fact that this new powertrain is far more than simply an Internal Combustion Engine. Where the previous V8 format utilised a KERS hybrid system which was effectively ‘bolted on’ to a pre-existing engine configuration, the Mercedes-Benz PU106A Hybrid has been designed from the outset with Hybrid systems integral to its operation.
The Internal Combustion Engine (ICE) is the traditional, fuel-powered heart of the Power Unit; previously known simply as the engine. For 2014 this will take the form of a 1.6 litre, turbocharged V6 configuration, with direct fuel injection up to 500 bar of pressure. Where the V8 engines could rev to 18,000 rpm, the ICE is limited to 15,000 rpm from 2014. This reduction in crankshaft rotational speed coupled with the reduction in engine capacity and number of cylinders reduces the friction and thus increases the total efficiency of the Power Unit. This down-speeding, down-sizing approach is the key technological change at the heart of the ICE structure.
For 2014, the notion of hybrid energy recovery has shed a letter (KERS has become ERS) but become significantly more sophisticated. Energy can still be recovered and deployed to the rear axle via a Motor Generator Unit (MGU), however this is now termed MGU-K (for ‘Kinetic’) and is permitted twice the maximum power of the 2013 motor (120 kW or 161 hp, instead of 60 kW or 80.5 hp). It may recover five times more energy per lap (2 MJ) and deploy 10 times as much (4 MJ) compared to its 2013 equivalent, equating to over 30 seconds per lap at full power. The rest of the energy is recovered by the MGU-H (for ‘Heat’); an electrical machine connected to the turbocharger. Where the V8 offered one possible ‘energy journey’ to improve efficiency via KERS, there are up to seven different efficiency enhancing energy journeys in the ERS system.
A more detailed description of the various components which combine to form the Power Unit can be found below.