At the heart of the TOYOTA Racing TS030 HYBRID challenging in the FIA World Endurance Championship is our innovative TOYOTA HYBRID System – Racing. Our petrol hybrid powertrain recovers energy under braking at designated energy recovery zones and delivers an incredible 300hp boost automatically as the car accelerates out of the corner. Find out more about how our hybrid racing technology works and see our exclusive video and CGI images after the break.
Our hybrid technology has been developed especially for racing. The TOYOTA HYBRID System-Racing (THS-R) powertrain features a 530hp, V8, 3.4-litre normally-aspirated petrol engine and 300hp hybrid system with super capacitor storage. This extra boost, combined with efficient aerodynamics, delivers a significant performance increase whilst the hybrid system can also be used to increase fuel efficiency when race strategy dictates.
The electric motor providing drive to the rear axle is positioned between the engine and the gearbox and delivers the 300hp boost automatically, with no need for the driver to request it. This means the boost can be controlled electronically to deliver the most effective power boost.
Energy is recovered, in the designated hybrid recovery zones mandated by the FIA, under braking from the rear drive shaft and stored in a super capacitor located in the cockpit. The extra power of up to 500kJ per hybrid recovery zone is delivered on the exit of the corner. To put this output in perspective, 500kJ is enough energy to lift a 2.5 tonne minivan over 20 metres vertically.
The number of designated hybrid braking zones varies with each circuit. At Le Mans for example, there are seven and the TS030 HYBRID recovers 500kJ each time; valuable energy which is used later in the lap to improve performance. Each lap of the 13.62km La Sarthe circuit sees a cumulative charge of 3.5MJ. To put this in perspective, a Toyota Prius Plug-in can store up to 10.3MJ on a full charge which takes around 3 hours. With each lap taking approximately three minutes 20 seconds this means that the race car can harvest the same energy in just 11 minutes.
Of course, with most of the lap spent under acceleration rather than braking, where energy recovery takes place, the actual charge time is much less. Each hybrid zone charges the super capacitor fully, even though the driver spends less than three seconds on the brakes with deceleration hitting almost 4G. So, in fact, the charge time for 10.5MJ gathered over three laps is an astonishing 63 seconds!
The key to this performance is the super capacitor technology, which is capable of charging and discharging far faster than its battery equivalent, making it ideal for motorsport and, potentially, future sporty road cars.
Also critical to the process is the regenerative braking system. As with a standard race car, hydraulic brakes work on all four wheels of the TS030 HYBRID, however an additional regenerative braking system is fitted to the rear. Here the Motor Generator Unit (MGU) performs as a generator during braking, harvesting energy directly from the drive shaft in a process which also slows the car, and converting it to electricity for storage in the super capacitor.
The combination of hydraulic and regenerative braking needs careful management to ensure predictable response and a smooth feeling for the drivers and this is achieved by the Electronically Controlled Brake (ECB) system. The capacitor’s charging level and the vehicle speed determine how much regenerative braking force is required and the system enhances this with hydraulic braking when needed.
This concept is fundamentally the same with all road going hybrids and helps make the TS030 HYBRID more energy efficient than it would be without a hybrid unit.
Energy formerly converted into heat, and thus wasted upon every application of the brakes, is now very efficiently converted into additional power. With hydraulic braking only at the front, the discs glow orange with the heat, but regenerative braking means less energy through the rear brakes, meaning less heat through the discs, which have no orange glow.
After braking and driving through the corner, power is delivered when the driver accelerates back towards top speed, with electronic controls ensuring power is delivered smoothly and consistently. With 300hp of boost giving a temporary power increase, the THS-R directly reduces lap times at Le Mans by more than two seconds compared to simulated non-hybrid laps in the TS030 HYBRID.
But the THS-R is not only available to deliver more performance. Depending on racing conditions, the hybrid system can increase fuel efficiency using exactly the same principles, with power boost used to compensate the power drop caused by leaner engine running. In endurance racing, both speed and efficiency are critical so TOYOTA Racing can count on hybrid technology to drive it forward.