Explaining the STR9

27/01/2014
NEWS STORY

'Saving the planet', 'going green'; it's hard to avoid these topics in the modern world and even Formula 1 and motor sport in general is being steered towards a less profligate technology with the threat of the world's supplies of fossil fuels running out one day.

Therefore, whether or not they are interested in these socio-political issues, F1 designers have faced a very busy couple of years when it comes to drawing up the blueprints for the 2014 Grand Prix car. In the case of Toro Rosso, that task rests on the shoulders of Chief Designer Luca Furbatto.

"It has been a fantastic challenge but very hard work," he admits. "Pretty much all the systems on the car are brand new and that's certainly a concern from a reliability point of view as the season progresses, because we won't have known reference points from the past few years. Everyone in Faenza and Bicester has worked very hard and we have invested in different technologies and simulations in order to be as best prepared as possible.

"We started STR9 in the summer of 2012, initially just purely on the simulation side. When James Key arrived in late 2012, he focused mainly on the 2014 car in terms of planning, simulation targets and internal resourcing whilst we were still designing the STR8. To his credit we were able to perform the first STR9 wind tunnel test shortly before Christmas 2012, much earlier than previous Toro Rosso projects.

"The biggest change to the regulations involves switching from a normally aspirated 2.4 litre V8 to a 1.6 V6 turbocharged engine, which is only one component of what is now referred to as the power unit, or power plant.

"The new power unit consists of an engine which is turbo-charged, a new and much more powerful version of the Energy Recovery System, operating as an electric motor/generator connected to the crankshaft (MGUK), and another electric motor/generator connected to the turbo (MGUH), running at a much higher speed," explains Furbatto. "The combination of these two energy recovery systems is the hybrid part of the new power unit package, the 'green' effect of the next generation of Formula 1 cars. The engine, although it's smaller and more compact, requires a fairly complicated energy management with all those motors and controllers working at the same time and exchanging energies between a battery pack and the two electric motors.

"The cooling side has been a massive challenge for us as we have also had to deal with the added factor of changing our engine supplier. In 2014 the hybrid proportion is much more significant and therefore it generates more heat, that needs to be cooled too. Furthermore, using a turbocharger means the engine requires intercoolers, which we haven't had on F1 cars since the mid-80s. Certainly, the radiator layout plays an important role in the overall car layout and we had a few moving targets during the design phase, which means we ended up sizing 17 different layouts for cooling on STR9 and eventually committing to just one!

"In doing so we relied on the work of several departments within Toro Rosso and we have invested heavily in doing dyno testing and core measurements to ensure that we are as optimised as possible in terms of cooling. I am sure that activities related to cooling refinements will continue over the course of this season."

While new engine rules have dominated the headlines, other aspects of car performance have also been affected by the regulations, starting with aerodynamics, where further restrictions have been imposed for 2014. Even if the emphasis has been on power unit packaging, the aero side is still very important and will in fact have an effect on how the new PU is run, specifically because of the 100kg per race limit on fuel.

"Clearly, we are packaging things in a way that will allow us some development flexibility also from the aerodynamic side because ultimately, we need to find a performance sweet spot between aero, PU performance, fuel consumption and cooling capability" continues Furbatto. "With this latest regulation there a finer balance between downforce and drag due to the fuel consumption effect which has not been such a big factor until this season."

Apart from engine and aero changes, the new rules also allow for an interesting new braking technology.

"Braking By Wire, or BBW is another new system that we will race in 2014," he continues. "In order to open up energy harvesting strategies during the braking phase the FIA will allow a semi active electronic control of the rear braking pressure line. The BBW will allow the braking load to fluctuate from pure engine braking to pure friction braking or any combination in between without the driver noticing it on the brake pedal! The exact amount of brake pressure on the rear line will be mapped against engine braking that will then be used to recharge the on-board batteries."

Another change in the rules is that the minimum weight of the car has gone up by 50 kg. That sounds a lot, but much of it is simply absorbed by the fact the new power unit weighs more than the V8 it replaces.

"In addition, there are enhanced safety structures for side impact and the chassis has been made significantly stronger than last year so the weight of the survival cell will go up in this area too," says Furbato. We will only be able to carry a very limited amount of ballast or no ballast at all, depending of the driver's weight. The possibility of running without ballast could be a limitation, both in terms of weight distribution, tune ability or simply tipping over the edge of being overweight."

The 2014 rules have meant a completely new car this year and Furbatto reckons around 98% of STR9 is brand new. "We started an aggressive weight saving programme on STR8 in order to get prepared for 2014. The only thing we kept of STR8 is the pedal set, although even here we managed to reduce the weight of it last summer.

"Looking at the STR9 project as a whole, I believe that all the departments in Faenza and also in Bicester have worked together more closely than ever before. That has been challenging at times but helped us to gel further as a team."

Check out our STR9 gallery, here.

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Published: 27/01/2014
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