Inside Racecar Engineering Offroad:

How the FIA implements WRC safety measures

Evolution of the Extreme E car

Brumos Racing’s Pikes Peak Porsche

The wonderful world of Autograss

Renault’s Rally3 contender

Ice racing in the Alps

…and much more!

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Toyota Gazoo Racing World Rally Team (TGR-WRT) has set its sights on a third successive WRC triple crown following a successful debut season in 2022 for its GR YARIS Rally1 HYBRID car, which swept the drivers’, co-drivers’, and manufacturers’ world championships.

The team continues to work hard to improve this winning package, and the most obvious change for 2023 is new rear fender bodywork featuring a revised cooling inlet for the car’s hybrid system. Other developments include a new specification of the engine with a higher output.

The season kicks off in Monte Carlo on January 19th – Return here for more technical insights throughout the season.

The TOYOTA GAZOO Racing World Rally Team clinched the 2022 FIA World Rally Championship manufacturers’ title with a win for Sébastien Ogier at Rally de España, just one event after fellow TOYOTA GAZOO Racing driver, Kalle Rovanperä, became the youngest ever winner of an FIA World Rally Championship title at the age of just 22 years and one day.

It’s the second year in a row that the team had managed a clean sweep of the available titles: An especially notable achievement given that it spans a major revolution in the technical regulations introduced at the start of the 2022 season when the all-new GR YARIS Rally1 HYBRID succeeded the Yaris WRC.

The Toyota GR YARIS Rally1 HYBRID was a brand-new rally car for 2022 designed to the revolutionary FIA Rally1 technical regulations, representing rallying’s most significant technological overhaul for a generation. Rally1 cars replaced World Rally Cars at the highest level of the WRC and feature a number of significant changes compared to their predecessors, including the introduction of technologies promoting sustainable motorsport.

For the first time, the cars in rallying’s top category have hybrid electric power. The 1.6-litre direct-injection turbocharged engine – one of the only features of the previous generation of World Rally Cars to be carried over to Rally1 – is paired with a hybrid unit that is common to every competing car.

The hybrid unit consists of a 3.9 kilowatt-hour battery coupled to a motor-generator unit (MGU), delivering an additional 100 kilowatts (134 horsepower) and 180 newton metres of torque during acceleration. The unit regenerates energy under braking, and the battery can also be plugged into an external power supply to be recharged during service breaks. It means that, with the engine and hybrid unit combined, Rally1 cars are capable of a maximum power output of 500 BHP and maximum torque of over 500 Nm.

Alongside hybrid power, Rally1 cars run on 100 per cent sustainable fossil-free fuel. With a renewable blend of synthetic and bio-fuel components, the fuel is the first of its kind to be used in an FIA motorsport world championship.

The regulation changes also cover the car’s chassis, which is formed by a spaceframe design that offers increased safety protection for the driver and co-driver compared to the previous bodyshells. On the outside, some of the aerodynamic features seen on World Rally Cars between 2017 and 2021 have been prohibited to control costs. Still, elements such as side skirts and large rear wings remain to provide stability, while air ducts can be used to cool parts, including the hybrid unit.

There has also been a simplification of the cars’ transmissions. The cars remain four-wheel drive but now have five-speed gearboxes with a mechanical shift and no longer feature an active centre differential. The suspension is also more straightforward, with a reduced amount of permitted damper travel. The TOYOTA GAZOO Racing World Rally Team made the most of all of the changes, becoming the first team of the new era to win a hybrid WRC championship. In total, 2022 marks the sixth occasion that Toyota has topped the WRC’s manufacturers’ classification, the third time since it returned to the series in 2017.

The Audi RS Q e-Tron won its first desert rally in Abu Dhabi, and now the next evolution is ready. The innovative prototype presents itself significantly improved for the 2022 Morocco Rally and the 2023 Dakar Rally. The body is new and features enhanced aerodynamics, lower weight and centre of gravity.

New operating strategies improve the efficiency of the electric drivetrain. The driver and co-driver benefit from more effortless operation in the interior and when changing wheels. Following these evolutions, the RS Q e-Tron now bears the abbreviation E2.

‘We’ve managed a good debut at the Dakar with the Audi RS Q e-Tron and our first stage victories in a motorsport discipline that is new to us,’ says Rolf Michl, Managing Director of Audi Sport GmbH and responsible for motorsport at Audi. ‘The entire team is working together and pulling in the same direction. As is usual at such an early stage, the drivers, co-drivers, and technicians quickly agreed on the next development targets. We have summarised the result in a new evolution package – the RS Q e-Tron E2.’

The RS Q e-Tron E2 launch marks the beginning of the second phase of the development program. In October 2022, Team Audi Sport will prepare for the 2023 Dakar Rally with the new prototype in Morocco. ‘The Audi RS Q e-Tron E2 does not adopt a single body part from its predecessor,’ says Axel Löffler, Chief Designer of the RS Q e-Tron. ‘We are doing away with the rear hood’s underflow to the B-pillars’ left and right. This solution reduces weight with modified lay-ups and optimised fabric layers of composite material.’

To comply with the prescribed interior dimensions, the cockpit, previously narrowly recessed towards the roof, is now significantly wider. The front and rear hoods have also been redesigned. This is accompanied by the lowering of the vehicle’s centre of gravity. ‘The T1U prototypes have to weigh 2,100 instead of 2,000 kilograms in the future,’ continues Löffler. ‘Given that the first generation of the RS Q e-Tron was overweight, it was still necessary to save several dozen kilograms.’

The aerodynamic concept in the body below the hood is entirely new. Its widest point is at the height of the cockpit, while the body tapers significantly towards the front and rear. Audi has now dispensed with the part of the fenders behind the front wheels and formed a transition to the door. Internally, this structure was called the ‘elephant foot.’ As a result, the designers saved more weight and optimised the airflow.

‘The aerodynamic aspect should not be underestimated in desert rallying,’ says Löffler. The new cockpit dimensions mean that the body has a larger and, therefore, less favourable cross-section. Nevertheless, it was possible to reduce the overall aerodynamic drag by around 15%. This does not change the top speed. It remains limited to 170 km/h in the regulations. ‘The improved air flow further reduces the energy requirements of the electrically powered car,’ says Löffler. ‘We implemented the aerodynamic calculations entirely using computational fluid dynamics.’

Energy management plays a crucial role here. The electric drivetrain of the Audi RS Q e-Tron E2 comprises an energy converter consisting of an internal combustion engine and a generator, as well as a high-voltage battery and two electric motors – one on each axle. The electronic control system of the complex electric drivetrain proved its worth in the first rally events. Challenges only arose in extreme cases. For example, Audi noted short-term power surpluses at the Dakar Rally when the wheels made less contact with the ground while jumping or on uneven terrain.

The FIA rules now intervene at a threshold of 2 kilojoules of excess energy and impose sporting penalties. ‘By comparison, more than one hundred times the amount of energy flows to the motors per second within the permissible limits [compared to the previous generation],’ says Florian Semlinger, development engineer for embedded software, application and test bench. ‘We could have made it easy on ourselves and set our threshold several kilowatts lower, but that would have meant performance disadvantages. Instead, we put a lot of fine-tuning into the power controllers.’ The software now recalculates two individual limits – one for each motor – within milliseconds. As a result, it operates precisely along the permissible limit.

The so-called auxiliary consumers also benefit from optimised control. The servo pump, the air- conditioning cooling pump and the fans have a measurable impact on the energy balance. During the debut season in 2022, the Audi and Q Motorsport rally team gained valuable experience that enables better assessment. The air-conditioning system, for example, works so aggressively that it could cause the coolant to freeze when constantly running at its maximum output. In the future, the system will run in an intermittent mode. This saves energy, yet the interior temperatures only fluctuate slightly, even over longer periods. The operating strategy for the fans and the servo pump has also been optimised. The systems can now be regulated differently for the lower load on the liaison stages than on the special ones.

The Audi drivers Mattias Ekström/Emil Bergkvist, Stéphane Peterhansel/Edouard Boulanger and Carlos Sainz/Lucas Cruz can look forward to their new workplaces. The displays are still in the driver’s field of view and located in the centre console in the usual style, and the central switch panel with its 24 fields has also been retained. However, the engineers have restructured the displays and controls.

‘The total of all the functions quickly creates confusion,’ says Florian Selinger. ‘That’s why, for the first time, the driver and co-driver can now select from four system areas using a rotary switch.’ The ‘Stage’ theme contains all the essential functions while driving competitively – such as the speed limiter in sections with speed limits or the air jack. The ‘Road’ part contains, for example, turn signals and the rear-view camera, functions that are often in demand during the liaison stages. The ‘Error’ option detects, categorises, and catalogues errors.

The ‘Settings’ section includes everything useful for the engineering team during testing or after the car arrives at the bivouac, for example, the precise temperatures of individual systems. Crews can now work much more quickly after a puncture. Simple, flat and easily removable body components replace the previous bulky covers for the spare wheels on the flanks. The new ten-spoke rims from partner Rotiform are much easier to handle. Drivers and co-drivers can grip them more easily and safely complete the change.

‘We have combined all the important lessons in a very short time. The result of our ideas is the E2 evolution,’ says Uwe Breuling, Head of Vehicle Operations Audi Sport. ‘Our development team’s determined, and cost-efficient work has prepared us perfectly for our second Dakar Rally.’ Following initial testing led by Arnau Niubó Bosch, Head of Test Engineering, Audi Sport unveiled the RS Q e-Tron E2 in Neuburg an der Donau on September 1, 2022. From October 1-6, 2022, the new technology will have to prove itself in competition for the first time at the Rally du Maroc. All three Audi driver pairings will contest the desert rally that begins and finishes in Agadir, southwest of the North African country.

The TOYOTA GAZOO Racing World Rally Team will begin the new era in the FIA World Rally Championship when the 2022 season begins and the GR YARIS Rally1 debuts on the legendary Rally Monte-Carlo from January 20-23 2022.

The GR YARIS Rally1 is the successor to the all-conquering Yaris WRC, which claimed a clean sweep of the manufacturers’, drivers’ and co-drivers’ in the 2021 season that concluded just eight weeks ago at Monza in Italy.

On the way to its debut in the famous Dakar Rally in January 2022, Audi Sport has tested the Audi RS Q e-tron for almost two weeks in Morocco under the most extreme conditions after testing in Germany and Spain. Once again, all three driver crews were involved. Dakar record winner Stéphane Peterhansel, Carlos Sainz and Mattias Ekström took turns at the wheel of the highly complex prototype with their co-drivers Edouard Boulanger, Lucas Cruz and Emil Bergkvist.

‘Driver and co-driver form an essential unit in the Dakar Rally,’ says Andreas Roos, responsible for factory motorsport projects at Audi Sport. ‘They have to feel comfortable in the cockpit. This was one of many topics we had on our to-do list after the test in Zaragoza. For the test in Morocco, we made modifications so that the driver and co-driver have more space in the tight cockpit and can also communicate better. The feedback was positive.’

Some of the conditions the test team encountered in Morocco were extreme. ‘The thermometer climbed to well over 40 degrees Celsius at times,’ says Sven Quandt, team principal of Q Motorsport. ‘Sandstorms also hampered the testing. In addition, as expected, some new problems arose in the high temperatures, which repeatedly caused interruptions to the testing and needed to be solved before the next test.’

‘We expect much lower temperatures at the Dakar Rally,’ continued Roos. ‘Nevertheless, we deliberately went to Morocco to test our concept under the most extreme conditions. Components such as the MGU, for example, were not developed for use in such high ambient temperatures. The drivetrain and other components were also pushed to their limits or even beyond by the heat. The insights we gained in Morocco are invaluable, but they also show us that we still have a lot to do before the Dakar Rally and there is not much time left.’

The high-voltage battery, which Audi developed explicitly for the Dakar Rally, is also a significant topic. ‘It’s all about optimum temperature management and being able to call up the battery’s maximum performance,’ says Roos. ‘This is where we are learning with every test. And that’s exactly why we are going to the desert with an electrified drivetrain: We are gaining an incredible amount of experience that we are sharing with our colleagues from road car development.’

Bahrain Raid Xtreme (BRX) has redesigned the Prodrive Hunter to meet the new T1+ regulations of the Dakar Rally recently announced by the FIA, which is now the top class alongside T1-E. The FIA introduced the new rules to help balance the performance of the four and two-wheel-drive cars in the T1 category.

The Hunter T1+ will run on larger tyres, with increased suspension travel and a wider track. 37in tyres on 17in rims, replace the current 32in tyres on 16in rims, with suspension travel increased from 280mm to 350mm, and the body width increased from 2m to 2.3m to accommodate. These changes have necessitated some significant adjustments to the drivetrain, suspension and bodywork. 

Prodrive has reconfigured the suspension geometry with longer wishbones and dampers, larger brakes accommodating the 17in wheels. The larger tyre radius increases the load in the drivetrain, so driveshafts, prop shafts, and differentials have been modified accordingly. The wider track means nearly half the bodywork has been redesigned, with restyling of the Hunter to suit the new regulations while keeping the same distinctive look.

Prodrive has taken the opportunity to increase the windscreen size and fit a new programmable wiper motor to improve the driver’s visibility. The onboard jacks are now lighter and more robust, lift the car faster, and are powered by an electric pump for additional reliability.

‘We are very pleased the organisers have addressed the disparity in regulations between the buggies and the four-wheel-drive T1 cars, where larger tyres had an advantage over rough terrain,’ says Gus Beteli, BRX team principal. ‘We’ve learnt a huge amount on our debut in 2021 and have put all this learning into improving the car and believe our new Hunter T1+ is a significant step forward. We are looking forward to returning to Saudi in January, where we will be looking to challenge for victory.’

BRX competed with the T1 car for the last time at Baja Aragon, where the Hunter showed pace-setting fastest times on eight of the rally’s 11 sectors. The first Hunter T1+ car is currently being built at Prodrive’s headquarters in the UK and will run for the first time in September 2021. The new car is also available to customers to compete in FIA Cross Country events, Bajas and Dakar in 2022.

For more insight into the Prodrive Hunter T1 Challenger, pick up Racecar Engineering March 2021 issue available here.

Audi has launched the RS Q e-tron for Dakar Rally in a bid to be the first car manufacturer to use an electrified drivetrain combined with an efficient energy converter to compete for overall victory against conventionally powered competitors in the world’s toughest rally.

‘The Quattro was a gamechanger for the World Rally Championship. Audi was the first brand to win the Le Mans 24 Hours with an electrified drivetrain. Now, we want to usher in a new era at the Dakar Rally while testing and further developing our e-tron technology under extreme conditions,’ says Julius Seebach, Managing Director of Audi Sport GmbH and responsible for motorsport at Audi.

The characteristics of the Dakar Rally present the engineers with unique challenges. The marathon event lasts two weeks, and the daily stages are up to 800 kilometres in length. ‘That’s a very long distance,’ says Andreas Roos, responsible for the Dakar project at Audi Sport. ‘What we are trying to do has never been done before – this is the ultimate challenge for an electric drivetrain.’

Audi has chosen an innovative charging concept as there are no charging opportunities in the desert: Onboard the Audi RS Q e-tron, there is the highly efficient TFSI engine from the DTM. It is part of an energy converter that charges the high-voltage battery while driving. Since the combustion engine operates in the particularly efficient range of between 4,500 and 6,000rpm, the specific consumption is well below 200 grams per kWh. The drivetrain of the Audi RS Q e-tron is electric.

The front and rear axle each feature a motor-generator unit (MGU) from the current Audi e-tron FE07 Formula E car with only minor modifications for the Dakar Rally. A third identical MGU is part of the energy converter and recharges the high voltage battery while driving. Energy recuperation takes place during braking. The battery weighs about 370 kilograms and has a capacity of around 50 kWh.

‘The battery is also a proprietary development that we have realised together with a partner,” says Stefan Dreyer, Head of Development at Audi Sport for motorsport projects. “As engineers, we see development potential in every component. In terms of the drivetrain system, we have already achieved a system efficiency of over 97 per cent in Formula E. There’s not much more room for improvement. The situation is quite different with battery and energy management, where the greatest development potential lies in electromobility in general. What we learn from the extremely challenging Dakar project will flow into future production models. As always, we are also working closely with our colleagues from road car development on this project.’

The maximum system power of the e-drivetrain is 500 kW. How much of this may be used during the Dakar Rally is still being finalised by the organisers. The electric drivetrain offers many advantages in this case as the electric motors can be controlled very precisely and thus ensure good drivability with any output. In addition, the car can recover braking energy. The Audi RS Q e-tron only needs one forward gear. The front and rear axles are not mechanically connected, as is also common in electric vehicles. The software developed by Audi takes over the torque distribution between the axles. Thus, it creates a virtual and freely configurable centre differential, which has the positive side effect of saving the weight and space that prop shafts and a mechanical differential would have required. Visually, the Audi RS Q e-tron also differs significantly from conventionally powered Dakar prototypes.

The Dakar Rally entry will run in conjunction with Q Motorsport. ‘Audi has always chosen new and bold paths in racing, but I think this is one of the most complex cars that I have ever seen,’ says team principal Sven Quandt. ‘The electric drivetrain means that a lot of different systems have to communicate with each other. Besides reliability, which is paramount in the Dakar Rally, that’s our biggest challenge in the coming months.’

The prototype of the Audi RS Q e-tron had its first roll-out in Neuburg at the beginning of July. An intensive test program and the first test entries at cross-country rallies are on the agenda from now until the end of the year. ‘This project’s schedule is extremely packed and challenging,’ says Andreas Roos. ‘Less than twelve months have passed since the project officially started. We had to begin the development before the regulations for alternatively powered vehicles had been finalised, and all the development took place during the Corona pandemic. What the team has achieved so far is unique. The roll-out was a special moment for everyone.’

Audi Q e-tron Dakar

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