Toyota TS050 2018/19 Technical Analysis
*Check out the 2019/20 Toyota TS050 HERE *
The 4th iteration of the Toyota TS050 raced in the LMP1 category of the WEC 2018/19 season and was Toyota’s most successful car to date. Not only did it finally win the Le Mans 24 hours in 2018, but the nature of the ‘Super season’ meant that the Japanese outfit got a second chance to win the prestigious race in 2019. To add to this, Toyota crossed the line first in every round of the 2018/19 WEC season and so unsurprisingly claimed both the drivers and manufacturers championship titles.
This 2018/19 version of the Toyota TS050 is an evolution of that raced in 2017. ‘Unlike previous years, the upgrades on our 2018 car are limited,’ highlights Pascal Vasselon, Technical Director of Toyota. ‘In addition to reliability improvements on the powertrain, we updated the cooling system and developed the bodywork within our 2017 homologation.’
These ‘limited upgrades’ also include a beefed up clutch as well as optimised wheel arches. Although the majority of the bodywork has been carried over from the 2017 version, with just two aero kits; low and high downforce, homologated for the 2018/19 season instead of the three packages used in 2017. But ultimate performance was not Toyota’s goal for the latest TS050 variant, reliability was.
Reliability
‘In terms of outright performance, in the past four years we have had a car fast enough to win Le Mans on three occasions, with no fundamental reliability issues. Nevertheless, we failed every time to win so we had to do something about it,’ highlights Vasselon. ‘In Le Mans you can expect that 30-40% of race circumstances will be beyond your control; this is the beauty and at the same time the horror of Le Mans. So we have largely changed the way we are preparing for the race this year, focusing more on unconventional race situations.’
This is why Toyota focussed on improving reliability for the 2018/19 TS050 right from the beginning. Clocking a total of 21,000km during pre-season testing allowed both the drivers and the team to practise dealing with a vast array of reliability issues and failure modes.
‘We have completed laps on three wheels, faking a lot of possible problems to see how the team reacted,’ says technical director Pascal Vasselon. ‘At the moment the general feeling in the team is that we are better prepared. The game in the previous years was first to achieve performance because to beat Audi and Porsche we first had to out perform them. This time we could handle things differently, with less priority on performance. We have done some [performance work], but nothing that compromises reliability. Reliability has been a major priority, but we have a baseline car that is basically reasonably reliable so we did not need to pile up massive mileage. Then we could dedicate more time and effort to the third item, which was the training of the team to handle the exceptional circumstances. And we have been sacrificing endurance mileage to train the team to things that are outside the normal working range.’
Toyota TS050 Hybrid Powertrain
The Toyota TS050 boasts 1,000bhp, half of which comes from the 2.4-litre V6 direct injection twin turbo engine and the other half from the hybrid powertrain. This hybrid powertrain consists of a front and rear motor as well as a high powered Toyota lithium-ion battery.
As ever, the biggest threat to a hybrid powertrain is the battery packs overheating. Therefore, complex air, water and air conditioning systems have been developed to try and remove any generated heat away from the batteries, minimising the risk of overheating.
Cooling systems however, add weight, complexity and reduce aerodynamic efficiency so another tactic is to develop the technology of the cells so that they can operate at a much higher temperature, and therefore not require as much cooling. In 2017, Toyota proudly stated that they had already increased the operating temperature of their battery by 10% compared to the previous year, and for the 2018/19 season this temperature has increased by a further 10%.
Cooling
During testing, the Toyota TS050 clocked lap times five seconds faster than the last time they tested at Paul Ricard in 2016. This was due to the fact that they had turned everything up to the maximum to stress the cooling system. However, due to the increased operating temperature of the batteries as explained above, the 2018/19 TS050 no longer has to run the compulsory air conditioning system and so has reverted back to a more conventional water-cooled approach.
‘What we have done was mainly on the hybrid side on the battery and the cooling of the battery,’ says project leader John Litjens. ‘The temperature that the cells work at is now much higher because of the lack of the air conditioning system. We don’t have an air conditioning system at all. In the cockpit we have the normal venting and fans.’
The removal of the air conditioning system also offers a huge weight advantage as there is no longer a condenser or compressor which also helps to reduce the time penalty in the pits. ‘As we saw at Le Mans [in 2017], if you have to change the front motor, you needed half an hour. The compressor was driven by the front motor and was part of the unit so when you change the front motor you have to disconnect the lines and you have to open the system. There was gas inside that you have to evacuate, you have to dry the system and then put it all back again.’ This modification also required the radiators to be larger which in turn meant changes to the radiator installation.
Chassis
The tub for the 2018/19 improved TS050 is the same as that of the 2016 car, along with the new engine and the battery storage system that was also introduced that year. This is due to an agreement by the three manufacturers at the time who agreed that they would all run their monocoques for three seasons and so Toyota were not due for a new one until next year.
Fuel
Another change for the 2018/19 season was the fuel supplier, which has switched from Shell to Total. However, Total have developed a blend that is so similar, this actually didn’t require any modifications at all. ‘From a fuel perspective there is nothing to adapt,’ says Litjens. ‘For sure the risk is the refuelling and even there we didn’t see any surprises. It could have been major. The target was to get a smooth transition. Total was given a target to make the fuel so that they could not do something out of control. We get the data sheets of the fuel, and the specific calorific energy and things would have been adjusted.’
One of the potential issues, that Toyota have been preparing their drivers for is the effect of the fuel cut. At the end of the straight during the braking zone, the hybrids want to recover as much energy as possible through their MGU-K units on each axle. This means that they are not only lifting earlier, but also increasing the duration of their braking phase. This was partly the reason behind the Nicolas Lapierre crash at Le Mans in 2017, where he passed an LMP2 car into the first corner, the fuel cut came in and the LMP2 driver ran into the back of him. In 2018/19, not only will this remain a problem, but the Toyota’s will also have to cope with the similar speed of the LMP1 non-hybrid contenders.
The 2018/19 Toyota TS050 claimed both the teams’ and drivers’ title for the 2018/19 season before the final round of the 24 hours of Le Mans and will race on into the 2019/20 season – making it the fifth year of competition for this tried and tested Toyota TS050 racer.
