PASCAL VASSELON Q+A

What has changed on the TS050 HYBRID?

I think the right question is what didn’t change! The answer would be shorter because in fact except some principles here and there which we kept to be able to capitalise on previous years’ development every single part has changed. In many areas the concepts themselves have changed. Obviously the engine concept has moved from V8 normally aspirated to V6 turbo; this is a significant change. The hybrid system remains a double KERS concept but the massive evolution for us is to move from super capacitor to battery. The front aerodynamic flow structure is as well a departure from the previous years’ concept.

Tell us about the new 2.4litre, V6 twin turbo engine…

We have clearly found the limits of a normally aspirated engine which clearly can be good and competitive in its sweet spot. It is definitely possible to make a fuel-efficient and competitive normally aspirated engine but the sweet spot is quite narrow and not completely robust when it comes to different conditions, like temperature or altitude change. The turbo just makes things much robust; you can achieve optimum power and combustion so you can compensate temperature or altitude within a bigger range. So the biggest gain is really the size of the operating sweet spot.

And a battery will replace the super capacitor…

A new storage solution is a big departure which requires a totally different management system. Even if everything looks quite similar, this change is a much bigger change than you would imagine. The levels of energy density are very different from a super capacitor to a batter, which changes completely the way to manage charge and discharge. But in terms of packaging in the cockpit, it is rather easy. We have similar external dimensions so we had to make little changes. On the outside it looks very similar but inside it is very different!

How have the aerodynamics evolved?

The aerodynamic concept, and particularly the front face of the car, has changed drastically. We have spent thousands of hours refining this new concept and this time we have done more than incremental changes; we have significantly changed the way we handle the flow structure after the front downforce-generating devices. The issue with front aero is that you obviously need downforce, so you need to deviate the flow otherwise you don’t create anything, but then you have to manage this deviation. The way we manage the wake of the front downforce-generating devices is significantly different on the TS050 compared to the previous cars.

What effect does the new engine have on the transmission?

A new engine brings a major impact and this is why initially our plan was to implement it in 2017. Bringing it forward one year has been extremely challenging in terms of designing the rear end of the car and the impact on the gearbox has been big. The torque levels of a turbo engine do not compare with a normally aspirated V8; they are significantly higher. So the gearbox has to be redesigned based on the first estimation of engine power. We kicked this off based on calculations because the engine was not running when we had to fix the specification of the gearbox. It has been an interesting model-based development because we had nothing actual to consider and experiment with.

How does the new powertrain change the cooling requirements?

One of the major impacts of a turbo is the increased cooling requirements. This affects the air flow and always creates a compromise in terms of aerodynamics. You don’t get anything for free so if you want to increase your cooling you have to deviate more air from the external flow. We try to minimise but it always comes with some loss of pure aero efficiency.

With more energy recovered under braking, does this affect the conventional brake system?

Brakes are one of the interactions which we have to master and control. Obviously if we brake more via the motors on the hybrid system, we brake less with traditional brakes. There is a risk that this creates instability; any small fluctuation with the motor braking has a big impact on conventional brakes. This is one of the challenges of moving to 8MJ; we have to work harder to manage how we use the traditional braking system.

What is the impact of the revised pit stop regulations?

We are working to optimise our operations considering the updated regulations, which allow more mechanics to work on the car during a pit stop. The reason for that change is to maintain some basic principles in terms of safety whilst making it more controllable by marshals. They were struggling in previous years to make sure everything was within the regulations, so now it has been made a bit easier for them to monitor pit stop procedures. For the teams, this change gives us more scope as it is more flexible, so there is the potential to be slightly faster.

What can you say about the rate of technical progress in WEC?

We have suffered from this unbelievable progress rate last year when we saw lap time improvements which have never been seen before in motorsport, especially within stable regulations. To have five or six seconds of progress like this shows the regulations offer quite a lot of development scope which is positive. But it doesn’t come for free; it requires a lot of resources. This means the environment has changed when it comes to developing a winning car. A while ago it was possible to have, for example, a very good hybrid system which could compensate a deficit in another area. Now everyone has progressed and we cannot afford to have any areas of the package that have not been fully developed. We have developed the TS050 on that basis.

What are your performance targets for 2016?

We want to be competitive. That is the minimum target we set ourselves – to be back in the game and competitive.