Turbulent times for Formula 1 engines result in unprecedented efficiency gains

Another trick Formula 1 has had for a while, that will soon be seeing adoption into production cars, are camless engines. Valves are operated by electronically-controlled pneumatic actuators. This allows the valves to open and close faster, and makes intermediate states (in between fully closed and fully open) a lot easier. It's also a major reason as to why crank speeds are as high as they are in F1 cars, as they valves can be actuated fast enough to avoid the valve float that would otherwise occur in cammed engines with valve springs. Production cars currently tend to top out around 9450rpm (the 6.3L V12 in the LaFerrari), whereas Formula 1 cars have pushed close to 20,000rpm (though usually 16,000 - 18,000) for quite some time.

Supercar manufacturer Koenigsegg is in the process of licensing their consumer version of the technology under the trade name "Freevalve". They've been developing it and testing it for an incredibly long time (I believe it's in its fourth or fifth generation), presumably to keep driving the costs down. I believe a few Chinese manufacturers are some of the initial companies signing on. It's around a 3-4% efficiency gain on its own.

There's other fun stuff too, like Mercedes-Benz's split turbochargers. Basically, the turbine is located near the exhaust still, but a shaft runs through the engine to the other side to the compressor which is near the intakes -- less piping to get a cooled charge, less turbo lag (again, shorter piping), a more compact engine footprint, and needing smaller intake side pods than using normal turbochargers. Be interesting to see if those trickle down to consumer autos, whereas currently manufacturers are instead integrating 48V electrical systems for electric turbochargers (and more advanced lighting, hybrid functionality, etc.)

It's not yet clear if the added complexity will be worth it for ordinary cars, but it's interesting. 47% efficiency from an IC engine is impressive.

Formula 1 is deliberately power-limited. But the Formula 1 technical rules [1] for the powerplant are all inputs, not outputs:

    Engine cubic capacity must be 1600cc.
    Crankshaft rotational speed must not exceed 15000rpm.
    Fuel mass flow must not exceed 100kg/h.

So that's where the drive for higher efficiency comes from.

[1] http://www.fia.com/file/40961/download/14591?token=5zH5vGzI

The plasma jet injection thing sounds pretty novel, but I imagine a lot of the efficiency gain is tied up in the lean burn. The brake thermal efficiency gains of lean burn are well known, as are the reasons we don't use them in modern road cars.

Burning so little fuel in so much air produces high levels of nitrogen oxides [1], bad for smog and acid rain and ozone. That's not a concern for an F1 car, but a serious issue for road cars that need to pass emissions tests since they can cause modern catalytic converters to stop functioning properly. See this note [2] on how unhelpful current NOx mitigation strategies have been.

I believe the addition of three-way catalytic converters was partly responsible for the stagnant fleet fuel efficiency somewhere in the 1980s, since they had to make engines run richer than before to not foul the cats; though, we've since developed better converters. (Also, safety equipment and luxury things increasing weight affected fleet numbers.)

[1] https://en.m.wikipedia.org/wiki/NOx

[2] https://en.m.wikipedia.org/wiki/NOx_adsorber#Market_use

Any mention of the Prius using the Atkinson cycle brings out the inner pedant in me. I suppose to a certain degree, Toyota makes the engine, so they can call it what they want, but late intake valve closing is clearly quite distinct from the engine Atkinson invented (and indeed that design might not have achieved one goal of Atkinson's engine which was to circumvent the Otto cycle patent).

Indeed, if there were any existing cycle for which it would make sense to name the Prius' engine after, it would be the Miller cycle, though that has always meant some sort of external compression of intake air (the original patent used a turbo, but all Miller cycle engine's I've ever seen have superchargers).

One other interesting note is that the Miller cycle works best with a supercharger due to increased relative boost at low RPMs, where the drop in torque due to the late intake valve closing hurts the most. The Prius nicely sidesteps this by using an electric motor at low speeds.

Reminds me of this article from 2004 of one person making similar innovations as entire engineering teams with huge R&D budgets 12 years later.

http://www.popsci.com/cars/article/2004-09/obsession-mr-sing...

It would be nice if Formula 1 would be a test bed for advanced technologies again like they did in the 90s with sequential automatic gearboxes.

I wish this article had more detail. Their description of the technology sounds a lot like stratified charge engines, which have been around for a long, long time... as in the Honda CVCC (the '70s forerunner to the Civic).

Perhaps the difference is DI?

Great! May be I am the only one in the nerd cicrle who dont want ICE cars to die and Electric cars to take over. I want, better and hugly more efficient engine along with cleaner fuel.

In the comment section someone pointed out about vaporized fuel achieving much higher efficiency, why is that not being used?

This is the sort of massively twisted world we end up with when externalities are not accounted for properly. Capitalism just spent in excess of 100 years and many trillions of hours to come up with hilariously convoluted designs still lagging massively behind the electric motor.