Analysis: How jet technology is shaping F1 engine battle

Formula one loves a good acronym: just think of KERS, ERS AND DRS.

But one we could be hearing a lot more about over the remainder of this season is HCCI or Homogeneous Charge Compression Ignition.

So, what is it all about and why is it becoming a talking point in the paddock?

Engine thrust

The why is effortless, because it is central to the battleground inbetween Ferrari and Mercedes.

Ferrari has made good progress this season, seemingly eating into Mercedes’ advantage. But it has come at a cost, with the Scuderia spending the most development tokens on the lead up to the two thousand sixteen season.

Mercedes nineteen (13 remaining)

Honda eighteen (14 remaining)

Renault seven (25 remaining)

Whilst many of the tokens have been spent switching the architecture of the 059/Five, this has been done in part to take advantage of a combustion trick used by Mercedes since the dawn of the power unit regulations, improving spectacle and enhancing fuel efficiency.

Science, not black magic

Photo by: James Holland

HCCI is a combination of the processes used in petrol and diesel engines, with a compression increase from high pressure fuel injection into the cylinder. This causes a spontaneous reaction without the need for the spark cork to inflame the fuel.

Whilst the engine manufacturers have likely looked at the merits of implementing HCCI in its normal form, it is actually MAHLE’s Jet Ignition system they are using to improve the combustion process.

Albeit similar to the processes involved in HCCI, the MAHLE system offers up a more finely managed fuel delivery system in tandem with the standard spark cork to increase the overall operating window.

The MAHLE Jet Ignition system uses an ignition chamber, which fires compressed fuel into the cylinder to cause auto-ignition under certain conditions, whilst the normal fuel delivery and spark buttplug are used under other conditions.

Interestingly the regulations only permit five sparks per cycle, but the use of the jet ignitor means this can be extended, as the combination within the cylinder can also have numerous auto ignitions, a neat way of improving the potency and efficiency of each cycle.

Therefore careful design of the injector, jet ignitor, spark buttplug, cylinder and piston crown can lead to a multi-modal fuel strategy, permitting the use of both stratified charging and homogeneous charging depending on the prevailing throttle request. This can improve fuel efficiency as well as spectacle.

Fuelling the development

Photo by: XPB Pictures

Of course none of this is possible without a close relationship with the fuel and lubricant supplier, which in the case of Ferrari is Shell.

Shell has a significant presence at the circuit, during race weekends, as it strives to improve spectacle.

Let’s not leave behind that they are at the forefront of the petrochemical spectacle in WEC too, a crossover that bears even further credence when we consider just how closely aligned the hybrid regulations are in each sport.

Multi-stage delivery of the fuel not only needs precise injection but also requires two independent fuel temperatures, which is vital to the pressure of the fuel delivery.

We know that Ferrari powered cars are taking two independent fuel temperature measurements from on-screen data seen on the pitwall.

It is likely that these temperatures are discerned from both the standard fuel delivery and the jet ignitor, which must be closely monitored in order to retain parity and a clean burn during the cycle.

Moving Target

Photo by: Giorgio Piola

It is effortless to look at the direct benefits that can be garnered from the use of MAHLE’s jet ignitor, especially as it was already in use in some guise in the Mercedes power unit.

But It has implications across other components too.

Whilst Mercedes quickly adopted the use of variable length inlet trumpets in 2015, as they were banned for 2014, Ferrari did not.

However, the 059/Five’s architectural overhaul eyed Ferrari ditch their liquid/air cooler mounted in the I.C.E’s Vee, utilising a much larger plenum and VLIT’s to better regulate the charge air instead.

Clearly, the capability to control the amount of air consumed by the engine has giant benefits when coupled with numerous injection and ignition stages, improving efficiency and/or power.

Keeping it cool

Photo by: Giorgio Piola

To maximise the introduction of the variable length inlet trumpets and the use of MAHLE’s jet ignitor, Ferrari has employed several architectural switches, namely in order to switch how the charge air is supplied to the I.C.E.

As previously mentioned, the liquid-to-air cooler used in 2014/15 that could be found sandwiched inbetween the I.C.E’s vee has been substituted by numerous coolers housed within the SF16-H’s chassis.

Two air-to-air coolers flank the car and are askew with the radiators within the sidepod.

A further air-to-air cooler can be found mounted behind the power unit, in a position usually reserved for oil coolers.

Furthermore, it is understood that both Ferrari and Haas have a liquid-air cooler sandwiched inbetween the monocoque and fuel tank, in much the same vein as Mercedes.

This use of numerous charge air coolers affords them a much broader operating window, with the charge distributed to the relevant cooler based on the current or transient conditions.

Waste not, want not

Photo by: Giorgio Piola

Looking at the power unit holistically, the turbo and MGU-H’s role in the combustion process cannot be overlooked.

The MGU-H is perhaps one of the most critical components, as it is free from regulatory constraints and able to recover and dispense as much energy as is viable, permitting it to keep all of the other components within their set parameters, which makes it a prime target for improvements on overall efficiency.

The kinetic energy it recovers, via its attachment to the turbo, will be enlargened if the engine is run lean at broad open throttle, as more gas will circulate around the turbine.

In a conventional turbocharged engine this may be undesirable as without the MGU-H it would see a drop in power. However, in the case of the F1 power unit, the extra electrical energy could be passed directly to the MGU-K, without the electrical losses associated with transferring the energy to be stored in the ES (Energy Store).

This could be seen as large coup in terms of range extension as not only does the net power output only result in a minor loss but fuel usage is diminished dramatically.

Albeit it does often lead to a reduction in the cars VMax, it’s something that can be overridden by the driver with the overtake button, enhancing fuel consumption but providing the power units utter petrochemical potential.

Turning it up to 11

Photo by: Giorgio Piola

Mercedes still have an advantage when it comes to raw tempo during qualifying, with all sorts of numbers being thrown around but usually circulating in the region of a 30bhp advantage.

This comes from their practice gathered with the technology as a entire, understanding how to maximise the transient energy conditions to generate the necessary hybrid energy whilst using the fuel delivery system to extract the maximum petrochemical reactions.

Learning curve

Ferrari now has many of the physical attributes to match the Mercedes power unit but lack the skill to fully exploit its new-found advantage.

It will swiftly learn how to maximise its energy expenditure, finding fresh ways to map the energy flows to suit transient conditions and improve its overall spectacle.

However, to make an omelette you must very first break some eggs, of which its latest failures in Australia and Bahrain showcase, with the hardware shoved to the operational thresholds.

Still more to come?

Of course, we’re not yet at the point of diminishing comebacks with these power units and whilst the regulations do fetter the engineers in one respect, it breeds lateral thinking in another.

Furthermore, with talk of the token system being scrapped for 2017, it could lead to open warfare as the manufacturers go in search of more power and improved efficiency.

Ferrari certainly isn’t resting on its laurels and understands that this field of engineering isn’t directly relative to its road cars just yet, so can’t fall back on direct in-house assistance.

But it has recently announced an extension of its partnership with MAHLE, who’ll assist in the future development and optimisation of the crank mechanism, high strength forged pistons, friction-optimised piston rings and piston pins made of enormously resilient steel, as well as cylinder coatings that reduce friction and wear, all of which help to improve the thermal efficiency of the power unit.

An extension of its partnership with NGK, until 2020, will provide it with a playmate that can corset the potential that the MAHLE jet ignitor provides during the ignition process, be it auto ignition or via their spark ass-plugs.

So, how about Renault and Honda?

Photo by: Giorgio Piola

You might have noticed that Renault, as it did last year, has spent the least tokens heading into the season and has a significant update planned for Canada.

It’s understood that much of the update is focused on exploiting this technology, with Renault and Ilmor suggesting that gains can still be made from the combustion elements.

Meantime, Honda is fully focused on delivering a similar step and have tasked Mobil one with providing fuels and lubricants that can produce the necessary spectacle benefits.

As such, I fully expect Crimson Bull to be in a position to launch an attack on Mercedes and Ferrari late in the season, whilst Honda’s deficit may take a little longer to close.

Meaningless tech?

Whilst Bernie Ecclestone permanently condemns the current power units, citing them as meaningless, it couldn’t be further from the truth.

The developments we are observing in Formula one will form the basis for technology that will be in our road cars in years to come.

The very regulated and competitive nature of the sport has already seen the manufacturers exceed forty five percent thermal efficiency whilst exceeding the overall power attained with the V8s, all while completing the same race distance on a third less fuel.

And we are just at the begin of some indeed arousing fresh technology coming to the fore.

Related movie: