Exclusive pictures of the Ferrari power unit
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By Nicolas Carpentiers, 23/11/2015 at 13:08 Magazine, Technical Leave a comment
F1i technical expert Nicolas Carpentiers takes you behind the scenes of Formula One and provides you with exclusive images of this year’s hybrid 1.6-litre V6 turbocharged power units. After Renault and Honda, the third chapter in our series is devoted to Ferrari’s 059/4.
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GOING BACK TO THE ROOTS…
Formula One can be seen as a schizophrenic sport, always striving to move forward and drawing on the brightest minds and most sophisticated technology in order to... go around in circles as fast as possible. Last year saw F1 reconnect with its past; after seven years of frozen development in the normally aspirated V8 era, the engine became crucially important once again. The pinnacle of motor racing had gradually turned into a one-dimensional sport with performance relying almost exclusively on aerodynamics. F1’s big hitters thus devised a new formula that aimed at finding more balance between aero, engine, V6 integration within the chassis, energy recovery, etc. Except that engine performance has simply become the new name of the game.
Granted, engine engineers have been put in the spotlight once again but the new technologies are so young and ground-breaking that it immediately created big gaps between the power units. Manufacturers were initially supposed to homologate their units before the start of the 2015 campaign, but this changed when Ferrari and Renault found a loophole in the technical regulations and the FIA allowed in-season engine development. Still, playing catch up with Mercedes, which has been the clear benchmark over the past two years, remains extremely difficult. This looked like an even taller order for Ferrari coming off its worst campaign in over two decades, but the revered Italian outfit managed to make some in-roads into Mercedes’ advantage. In order to achieve such feat, Ferrari head of engine operations Luigi Fraboni explains that Maranello’s power unit was given a complete overhaul last winter.
“We started with last year’s engine [the 059/3] as a basis, but we developed it to a much better product,” he is quoted as saying by Racecar Engineering. “But we realised there were others better than us so we reworked everything.
“A big effort went into combustion, we looked at the turbo, getting the most out of the energy recovery and we did a lot on the oil system. We looked at better knock control too, and we had to get better correlation between the software and how the engine worked in reality. In the end, we ended up with basically what is a completely new engine.”
Changes are not visually striking, save for the oil tank being placed at a different place. On the 2014-spec F14 T, it was positioned at the back of the internal combustion engine [ICE] and sat within the gearbox casing, right above the MGU-K. That installation used to be commonly used… before 1998! This year, the oil tank occupies a more traditional spot, namely between the chassis and the engine. Such assembly improves the package’s centre of gravity and allows for shorter and lighter pipework. The oil tank is separated from the engine when the latter features a dry pump system. F1 cars have elongated oil tanks, as this shape is better suited to cope with centrifugal forces in the corners.
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… BUT NOT ALL THE WAY
However, the overall architecture of the V6, which was designed by Lorenzo Sassi under the stewardship of Mattia Binotto, has not been totally revised. The intercooler’s shape may have been slightly altered compared to 2014 (see above), but it still sits within the Vee of the engine. As a reminder, its Mercedes counterpart is lodged within the monocoque and ahead of the engine, while we have already mentioned Red Bull-Renault’s split-intercooler design, with one element featuring in each sidepod. As for Honda, the McLaren MP4-30 is fitted with a big intercooler in its right sidepod. Ferrari has gone for an air-to-water intercooler (like Mercedes) and placed it at the heart of its engine in order to free up some space in the sidepods, thus limiting airflow resistance.
This very neat and compact package allows having shorter pipework between the compressor and the intercooler – at least when compared to the Renault and Honda architectures. Such design theoretically reduces the infamous ‘turbo lag’. However, this installation might not be the best thermally speaking, since the intercooler is lodged between two banks of red-hot cylinders. But Ferrari engineers have managed to stave off any potential issues by improving the SF15-T’s overall cooling.
On the picture above, one can notice that the intercooler ducts are roughly covered with an insulating material in order to preserve the cooling air about to enter the plenum chamber. Below is a diagram describing how the airflow travels in the Ferrari 059/04.
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INCREASING THE TURBINE’S SIZE
Eager to maximise aerodynamics and have a tight rear end on its 2014 charger, the Scuderia ran a very compact turbocharger installation last year. But it ended up compromising outright turbine efficiency, as aero gains did not make up for the lack of engine power. Indeed, a smaller turbine will de facto generate less power and more back pressure, which ends up penalising the internal combustion engine (ICE) in the higher RPMs (since wastegates are quite often open).
“A definite weakness of last year's car was that the amount of electrical energy we were able to recover from the turbo was not really good enough for producing competitive power levels during the race,” Ferrari technical director James Allison admitted when the new SF15-T was launched.
“It was one of the reasons Ferrari's qualifying performance was relatively stronger than race performance last year. We have tried to change the architecture of the engine to make it a better compromise."
When the time came to design the 059/4, Maranello engineers reconsidered the respective importance of engine and aero and decided to increase the turbine’s size. The device now sits within the gearbox housing, which also includes part of the manifold, the collector and part of the single exhaust. Having a bigger turbine means that the MGU-H absorbs more power from the turbine shaft, which in turn leads to greater electric deployment. In just one season, Ferrari has succeeded in solving the issues that are currently plaguing Honda. This has been achieved through a less bold but more coherent technological approach, clever recruiting, and massive investment.
What’s more, Ferrari’s partnership with Shell has been strengthened in order to improve energy efficiency and prevent knock (uncontrolled explosions that disrupt the combustion process).
“Last year we were developing in parallel with Shell, but this year we have set targets to them in terms of performance and especially knock,” Fraboni added. "They now know where we want to go and what we want to achieve with the engine and they have to get there.
"So each time we go to the dyno, they will bring candidate fuels to test to make sure we have the best for the races. I think now it is a very close relationship.”
When all combined, these evolutions would have unlocked an extra 60bhp on the Italian power unit (though only Maranello engineers actually know how much ground they have made) and enabled Ferrari to cut the gap to Mercedes.
On the picture above, one can easily spot the radiators, which have a flatter positioning and feature a clever system of louvres that can better channel the airflow on entry and exit (click here for more details).
Below, one can also notice that most components have been streamlined in order to improve insulation and internal aerodynamics.
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A LESS TWISTY DESIGN
Last year’s 059/3 had a very long manifold, that would climb upwards along the ICE and wrap around it.
The new-for-2015 pipework is shorter, more compact, and less twisty. Thus, it can feed more power to the internal combustion engine, while also making the turbine work more efficiently. The latter can produce more energy, which in turn benefits the MGU-H. The tubes sit closer to the car’s floor, reaching the turbine from below. Said turbine seems to have been lowered, while the wastegates installation is also different from last year.
Also worth noticing are the yellow-sealed ducts used to feed cooling air to the engine. Water circulation inside the engine was one of the first examples of CFD (computational fluid dynamics) application. This is due to a high degree of correlation between simulation and reality, as the liquid is flowing in a closed circuit (CFD applications on aerodynamics are a very different story).
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LOOKING AHEAD TO 2016
Ferrari’s MGU-K was kept at the back of the ICE, a different position compared to the Mercedes, Renault, and Honda installations. All other engine manufacturers have their motor-generator units placed on the left-hand side of the V6 and towards the front. It seems that Maranello actually intends to do the same in 2016 in order to further declutter the rear of its next car (without compromising engine performance like it did last year).
After introducing upgrades in Canada and Italy, Ferrari was supposed to spend its final four tokens ahead of Austin in order to enhance its V6 and prepare 2016. Yet, while the latest specification does improve overall engine reliability (which does not cost any token), it was not the prototype version people had expected to see. When asked about what Ferrari had in the pipeline for next season, Sassi had remained quite vague.
“As for our development tokens, we still have four left and plenty of ideas on how to spend them, both on increasing power for this season and also looking ahead to 2016,” said the chief power unit designer.
It must be noted that time is less critical this year, with engine manufacturers all agreeing to have the power unit development restrictions relaxed for 2016 (the decision still needs to be ratified during the next World Motor Sport Council meeting in December). In-season development will be allowed once again, while the number of allocated tokens will stay at 32 when it was supposed to decrease to 25. Furthermore, the components that were supposed to become totally frozen (as per Appendix 4 of the technical regulations) will finally be open to modifications. These include the upper/lower crankcase, the valve drive, the covers, part of the crankshaft, the air valve system, and ancillaries drive.
After poaching top personnel from rivals – like former Mercedes man and combustion specialist Cédric Cornebois – Maranello engineers look to use this greater leeway to make the Prancing Horse gallop again.
“The engine is still at the beginning of its development and we are still having new ideas each week, there is still much more to come,” Fraboni concluded. But will it be enough to eclipse the Silver Arrows?
Izvor