Besides regulation changes, the biggest swap on the grid was McLaren reuniting once again with Honda, while ditching the current dominating power plant by Mercedes. According to Ron Dennis, this was done because the engines have become so complex, that no customer team gets a chance to customize the engine as they see fit. That is coding wise. The energy recovery systems and the electric motors that feed that power back to the engine have to be carefully calibrated, a job Dennis beliefs is basically impossible as a customer team. It’s no longer about how you set-up the car (suspension, rake, brakes, etc.) as these new systems clearly affect every set up parameter you can think of.
Look at Renault and their fall off grace. The way the engine delivers the power affects the chassis, or look at Merc’s biggest chink in their armor (its brakes). And so, McLaren, for 2015 kissed Mercedes sayonara. Though their start of the season has been far from ideal, we can now see why they have been plagued by countless heating and power issues since the pre-season.
Honda’s engine is radical and it makes even Mercedes radical split turbo look mundane. Now there is no need for me to try and explain this. Instead I’ll leave you with a few lines from the great technical mind of Craig Scarborough:
Honda has split its turbo, but the way it has done so is different to Mercedes, as the turbo sits within the tight confines of the ‘V’ of the engine, along with the MGU-H.
Honda has pioneered the use of an axial flow compressor....Rather than a large centrifugal fan, there are a series of smaller fans along a shaft.
This design spins up quicker, although it may lack the maximum possible boost, which is not such an issue in this fuel-limited formula...unconventionally, the ERS module ahead of the motor combines the battery and both control electronic boxes (one each for ERS-K and ERS-H) into one unit.
McLaren went extreme with its aero design, and asked Honda for the most compact engine they could create. This same formula failed Ferrari miserably in 2014, and got a lot of people fired. But truth be told, for some reason, I trust the Japanese more when it comes to miniaturizing complex technology into a simple to use bolt on and race high performance engine.
You may read the full article at Autosport.