Q&A with Toro Rosso Technical Director, James Key and Head of Aerodynamics, Brendan Gilhome.

The new regulations the biggest change in a decade?
James Key: From the chassis side, I'd say more than that. In my 20 years in F1 it's the biggest chassis change I can remember. In '98 the narrow track had just arrived and there were various tweaks up to 2009, when a larger change occurred, but other than the front wing it was still based around principles that we knew. These rules however, include a track change, significantly different tyres and a new aero regulation as well. From a chassis point of view it's all encompassing with a lot of new things to learn.

Is it a new philosophy, for example on the aero side?
Brendan Gilhome: The front half (of the car) is completely new, with a swept front wing and a lot more freedom around the front of the floor, which means you can generate more downforce. There is also more freedom at the rear: you have a wider floor, a higher diffuser, the diffuser starts earlier and the rear wing is wider and lower. The philosophy for some of the car is something that we can take across from last year, but other areas require a complete re-think. The front wing position and shape has changed as well as all of the front floor. There is a lot more opportunity to explore different ideas and explore concepts that you hadn't been allowed in the past.

Refreshing for you guys then?
JK: It's nice to have a bit more freedom. We probably haven't had as many aerodynamic tools to play with since 2008, But then the rules tightened up in 2009 and even further in 2014. Now, some freedom has returned and that's a great challenge for the aero department.

Will all the teams have gone down the same route? Is the science of aero evolved to the point where you can look at the numbers and all the teams will have converged in their thinking?
JK: It's going to be really interesting to see what happens because one of the questions we asked ourselves when we started this project, is what makes a good 2017 car: we don't know the tyres yet, the aero has changed quite significantly, particularly when it comes to managing certain areas of the car where you have not got a philosophy that carries over from last year to this, so you've got to start from scratch in some areas. What makes a good car aerodynamically and mechanically for 2017? What makes a good car built to these regulations? That's the million dollar question. You have to base your decisions on how much development potential there is and then come up with development targets you believe are good. This is the twisted enjoyment of new regs! Looking at how advanced the technology is now in wind tunnels and with CFD, I would say teams are less prone to making big mistakes.

BG: I agree that a lot of the loopholes that existed over the years were tightened up and now that they are expanding again, everyone is a lot more aware of the limitations of the regulations. However, the regulations were evolving until very late last year and we didn't really have the first firm direction out of the working groups until mid-February (2016.) In order to work on the aerodynamic development, you need the tyres (for the wind tunnel) and we didn't get those until late-April. When you have additional freedom, at the start it's quite easy to find additional performance, but it can run out very quickly as well. You don't have long to make your choice and if you make the wrong one, it can have a big impact on performance for the next year.

Did that process involve a mass of CFD work?
JK: You're limited on how much CFD work you can do (in the regulations) and it's interesting how the limitation plays its role in all this because, yes, there was a lot of CFD for the conceptual work around the regulations and we adapted as the rules evolved.

But the effective limitations means that you are short on time and also limited on how many runs you can do with CFD, how much of your CFD resource you can use and how many runs you can do in the wind tunnel. Therefore you need to focus carefully on all that. Wind tunnel and CFD testing has changed dramatically because of the regulations. It pushes you towards greater efficiency and also to do more complicated things, such that you extract the most you can out of a number of runs or from computing resource. CFD is a big early player in all this but you have to correlate with the wind tunnel at some point. You can't go too long before doing some physical tests.

Is there any carry-over from last year's car to this?
JK: Nothing has been carried over, it's a clean sheet of paper.

BG: CFD work was also affected by the late confirmation of the rules. Normally you advance first with the CFD, but you didn't know about the tyres or the regulations until late. The model tyres came in late April, which meant the serious work in both wind tunnel and CFD could only start then. Previously it would have started in January or even December of the year before.

JK: It was late given the size of it. The '14 reg changes on the chassis side in combination with the new power unit also coming in were substantially less in size and in terms of philosophy change for aerodynamics. But these are a complicated set of regs and they took a bit of time to mature, but every team is in the same boat.

BG: But I think that lateness means it will be interesting to see what paths the teams take: some might take more risk, others might be more conservative...

JK: ...which means we might see some different solutions, which has not been the case in recent years. It might mean we have some diversity, at least in the early part of the season.

There's another important change for Toro Rosso - the move to Renault. How much of your package is influenced by that?
JK: What Toro Rosso needs is stability with its power unit supply and a competitive engine. If you look back at the last three years, through unfortunate circumstances we've always had a deficit on the power unit side. That has affected our performance and the number of points we've scored. That has been frustrating because the aero guys have done a fantastic job with the chassis and we've improved a lot in other areas, operationally and in terms of our understanding of the tyres. With the great turnaround we saw from Renault last year and a different approach and momentum that they've got now, hopefully this will be the best power unit we've ever hard in the hybrid era. For once we will have something that is much more competitive.

BG: I think the challenges we've had over the past two or three years with the power unit, pushed the rest of the team to be better, striving to find that little bit extra.

JK: We've also got driver continuity, which is really important when you go from one set of regs to another. Imagine if you had two rookies in the 2017 car! You would have no reference points at all. So on the power unit and driver side it's positive, which just leaves the chassis as an unknown. We always set ourselves ambitious targets. In the past we have tended to push as hard as we can for the start of the season and then see what we can do, what we can afford, depending on where we are as time goes on. This year we are taking a more long-term view over the 20 races.

So is the planned pace of development much bigger and faster this year?
JK: With new regs there's a lot of performance to be had , so there will be a development war over the whole year. Our list of developments is bigger than usual, because we've left lots of possibilities in. I suspect it will be a very busy year with plenty of performance still to be found.

On the aero side, will we see more variations in downforce levels this year?
JK: This year there's potentially a bigger range of levels you might want to choose because your balance of drag-related sectors and downforce related sectors of a track changes. So there will be a slightly larger spread of wing levels. It will also be interesting to see the lap time effect. We are talking about a nominal 5 second lap time improvement over a 2015 car when the targets for these new regs were put forward. But at which track? Monaco or Monza? We have seen from simulation with the '17 car that the effects of these regs are very track dependent and that will lead to a different aero and mechanical set-up to what we have been used to.

BG: Because the front and rear wings are larger, they are actually more efficient than they were last year, so there's definitely a balancing act and it will be interesting to see how that plays out with the tyres and how much power you've got.

JK: Absolutely right, as the tyres play a big part in deciding what wing level you should run. If you have tons of mechanical grip it will tend to push you to running less wing, and the reverse for lower grip conditions. This will also dictate how we go about setting the car up, there will be a lot to learn about the tyres and their behaviour.

With the cars cornering faster, have you had to strengthen various components on the new car?
JK: Definitely, starting with the suspension and all the attachment points because potentially, all your load levels will be higher for longer. Look at start performance for example: you have bigger contact patches (from the tyres) so you have something with higher static friction levels to try and get away off the line and you also have more weight in the car, so all the suspension, gearbox and chassis load cases change, the same for cornering and braking. But you have no historical data at present to work with, so you have to simulate your best guess of what your peak performance is likely to be, which means simulating what you expect to see at the end of the 2017 season. But you don't want to make things bigger and heavier than they need to be.

BG: In aero terms, you are always looking for that extra space, because for example, a smaller wishbone cross section is more desirable. With the regulations set quite late it takes a long time to understand the implications of everything and this had a knock on effect on the development of the car. So if a component needs to be larger we need to know as soon as possible to optimise and adapt and look at the performance implications of that.

JK: And now we're just looking forward to getting going on track!

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