Inside the Maserati MC20’s new V6
Maserati’s first supercar in a generation, the MC20, is going its own way, with no hybrid and some clever combustion tech. Here’s the nerdy detail.
As remarkable as the fact that Maserati chose to develop a new powertrain for its new supercar flagship, the MC20, is the speed with which it has created what is not an entirely conventional internal combustion engine.
The biggest point of difference is the pre-chamber ignition system: a feature of contemporary Formula 1 V6 engines, a series-production car first and the fruits of a research project Maserati only green-lit in 2015. Early findings showed huge promise from a performance standpoint, and in 2017 Maserati’s engineers concluded the idea could also meet emissions and drivability targets.
In 2019, they had the nod to industrialise the V6, dubbed Nettuno, with a view to powering the MC20. And in 2020 Maserati pulled the covers from the new car. Clearly, elements of the Modenese population are horribly sleep-deprived… But their loss is our gain.
WHAT’S IN A PRE-CHAMBER?
Logically, a pre-chamber’s a small chamber around a central sparkplug (the Nettuno also has a second plug per cylinder, offset) linked to the main chamber by profiled ports. Rapid and complete burn of the mixture is key to power and efficiency, and the pre-chamber promotes both in the way it triggers combustion: dynamic and targeted crests of flame from those ports. Think of the effect as being a little like the more homogeneous drenching of a watering can with a rose versus the unrefined slug of one without.
The interplay between the pre-chamber, its spark plug and the plug in the main chamber also gives Maserati a high degree of control over the combustion process.
The big advantage of the pre-chamber is that Maserati’s able to run a high compression ratio (11:1, versus, for example, 9.6:1 for Ferrari’s turbo V8 in the F8 Tributo) without running into pre-ignition problems. In turn, the Nettuno V6 generates a healthy specific power output – 621bhp and 538lb ft of torque from 3.0 litres. By way of comparison, McLaren’s new 3.0 V6 (which has, it should be noted, been designed specifically as part of a hybrid powertrain) is good for 577bhp and 431lb ft. Honda’s bigger, 3493cc NSX V6 (ditto) makes 500bhp.
In turn, the pre-chamber’s performance has allowed Maserati to make gains elsewhere. The engine’s turbos are relatively modest in size, because they can afford to be, and smaller turbos are less laggy. And creating a narrow-angle V6 with the power of a V8 means the MC20 is smaller, lighter and less draggy than would otherwise be the case.
Crucially, the V6 has been designed to go without a hybrid system, unlike rivals
A MAGIC-BULLET TECHNOLOGY, THEN? Matteo Valentini, Maserati’s chief engineer for performance petrol engines, is proud of the pre-chamber’s advantages but quick to point out that the Nettuno’s impressive numbers aren’t the result of a single innovation. In every regard it is an entirely contemporary high-performance engine, with an all-aluminium construction (unit weight is just 115kg), a low-inertia finger-follower valvetrain, variable valve timing and a high-pressure, twin-injector fuel-injection system. Crucially, though, it has been designed to go without a hybrid system, unlike new engines from most direct rivals.
So, will Maserati inevitably attempt to amortise its R&D spend by deploying the Nettuno elsewhere? It says not, and that this special engine will be reserved for the MC20. But that isn’t to say its learnings won’t find their way into the other Maser motors. ‘You will not find this engine in other applications,’ explains Valentini. ‘You will find a different engine which will share the Maserati pre-chamber, twin-combustion technology.’