The long road to convergence for sportscar racing's new golden age

It was a historic moment. The great and good from the Automobile Club de l’Ouest and IMSA sat on stage and told the racing world what it had wanted to hear for years: that the same cars would battle it out for the overall victory at the Le Mans and Daytona 24-hour endurance classics and right across the two series. An announcement, you might think, deserving of a 21-gun salute from the National Guard or a ticker tape parade through the streets.

Yet for all the euphoria on the eve of the 2020 Daytona 24 Hours when the convergence between the top-class prototype rules of the two governing bodies was revealed it was just a staging point – perhaps a flag-in-the-sand moment – on a long and winding road. There was still work to be done to align what was now being called LMDh, the category that had grown out of IMSA’s vision for a successor to the Daytona Prototype international class, and the Le Mans Hypercar rules of the ACO and the FIA. It would be another 18 months or more before sportscar racing nirvana, on the verge of which we now stand, was achieved.

The difficulties ahead were illustrated over the course of the convergence press conference. IMSA boss John Doonan, newly incumbent in the job after taking over from Scott Atherton at the end of the previous year, announced on stage that LMH cars would be able to race in the North American series from the get-go. In the media scrum that followed, he back-tracked. There was a desire to see that happen, he explained, but it remained a work in progress.

IMSA knew all too well the difficulties of matching the performance of the LMDh prototypes, developed like their predecessors out of LMP2 machinery, using an off-the-shelf rear-axle hybrid system with the bespoke four-wheel-drive LMH machinery. It wanted assurances that a true equivalence could be achieved before it opened up its series to the high-tech machinery from the world stage. But the reality was that the same hurdles had to be overcome if manufacturers taking the cheaper route to the pinnacle of sportscar racing were going to sign up for the WEC.

Or sign up to build LMDh cars in the first place. Porsche put its hand up within minutes of the Daytona announcement and stated its interest in the category for the simple reason that it allowed it to compete across two arenas on a cost-effective basis. Sister marque Audi followed quickly afterwards, though, of course, it has long since abandoned its aspirations to return to the top of the sportscar tree.

No one was going to commit to contest the WEC with an LMDh if they believed they had no chance against an LMH. As one insider present in some of the technical meetings that followed put it, “the prospective LMDh manufacturers looked across the table and said, ‘Do you think we are going to come to Le Mans just to be beaten by the LMH cars?’”. Concessions had to be made in the LMH camp, and to a lesser extent on the LMDh side. But that ground was given on both sides for the good of the sport.

The new LMDh category was formally announced ahead of the 2020 Daytona 24 Hours by the bosses at the ACO and IMSA respectively

Photo by: Michael L. Levitt / Motorsport Images

Toyota, the leading player in the formulation of the LMH rules, had long since made a significant compromise. It agreed to the introduction of Balance of Performance in WEC, which was a condition of Aston Martin’s entry in the summer of 2019. Now a manufacturer that had been the last man standing after first Audi and then Porsche axed their LMP1 programmes came to accept that more ground had to be given.

“We have always been supportive of the convergence in the sense that we were desperately looking for competitors joining the series,” says Toyota Gazoo Racing Europe technical director Pascal Vasselon, who had gone on record a couple of months before Daytona 2020 suggesting he was not averse to what were then being called DPi 2.0 cars being allowed into the WEC. “Anything that created an incentive for people to join had to be good.”

Peugeot, which had announced its LMH programme in November 2019, took the same big-picture view.

“We have to assume that we will be paid back by the quality of the championship in the next years,” says Olivier Jansonnie, technical director of the 9X8 programme.

"There was a shared goal. No one went against the grain, because we all wanted a nice big grid" Laura Wontrop Klauser

Vasselon believes that the COVID pandemic that followed quickly after the Daytona announcement solidified the convergence process: it concentrated the minds of the protagonists involved on what needed to be done in difficult times. An “accelerator”, he calls it: “It probably made it happen easier, and stronger.”

What followed in the months after that historic day in January 2020 is described as a “highly collaborative” process by IMSA’s vice-president of competition Simon Hodgson.

“Everyone looked at that long-term picture and was prepared to really do some self-evaluation of what was best for the sport in general,” says Hodgson. “There was a real appreciation by all concerned, whether they were an LMDh or an LMH manufacturer, that there would have to be compromise to move towards a common goal.”

Laura Wontrop Klauser, programme manager of Cadillac’s LMDh project, offers a similar perspective: “There was a shared goal. No one went against the grain, because we all wanted a nice big grid.”

Leading LMH manufacturers Peugeot and Toyota were both willing to accept compromises to ensure greater competition

Photo by: Toyota Racing

The start date of the brave new world of sportscar racing was originally a year ahead of where it ended up. The plan was for LMDhs to come on stream in the IMSA SportsCar Championship in 2022 and, in theory at least, in the WEC from the start of the 2021-22 season.

The WEC was at the time of Daytona 2020 in the midst of its first, and thanks to COVID its only, season run to the winter-series format starting in the late summer and climaxing at Le Mans in June. The idea of a first draft of the LMDh rules being published in March 2020 seemed hopeful even before COVID and the introduction of LMDh was surreptitiously put back to 2023 at the delayed running of Le Mans in 2020.

The first big step towards convergence actually came in the summer of 2020 when major changes were announced to the LMH rules to bring them into line with what was planned for LMDh. Both power and weight were reduced, and significantly so.

The minimum weight for an LMH was reduced from 1100kg – the figure to which it had risen on Aston’s commitment to bring a race version of its Valkyrie road car – to 1030kg and 1040kg for two and four-wheel-drive machinery respectively. Maximum power came down from 585kW or 785bhp to 500kW or 670bhp.

These changes had a big impact on the LMH programmes already in place. Don’t forget that the new breed of WEC prototypes were due to start racing just eight months after the convergence announcement in early September at the start of the 2020-21 season. Toyota’s LMH was already in build at this time, while Peugeot was making some big decisions about its programme. The reduction in weight of Toyota’s GR010 HYBRID would ultimately result in a not-insignificant redesign for its second season in 2022, while Peugeot abandoned plans to use a V8 powerplant in favour of a V6.

The moves announced in May 2020 were far from the end of the convergence process. The elephant in the room was still four-wheel drive and how to mitigate the advantages that come with a front-axle hybrid system – both in terms of traction and braking stability.

It took until July 2021 for the final pieces of the jigsaw to be put in place. The key piece of the puzzle was the move of the speed at which hybrid power could be deployed via the front axle out of the technical regulations. Instead, the speed that had originally been set at 120km/h (75mph) in the dry and 150km/h in the wet would be governed by the BoP.

From this season, LMHs are operating in four-wheel-drive mode for the most part in a straight line. The torque transfer allowed across the front axle has also been mitigated to what Vasselon describes as “the minimum possible”. The nuts and bolts of this rule were only finally agreed in December of last year.

Hybrid deployment from the front axle of 4WD LMH cars, a key performance differentiator in the wet, was moved out of the technical regulations into the remit of BoP for 2022

Photo by: FIA WEC

There was also a concession on the LMDh side. Measures were put in place to ensure that LMDh cars cannot use their rear hybrid system to aid traction control.

At the same time, the wheel and tyre sizes of the LMDh and LMH machinery were brought into line. The option for LMHs homologated after 2022 to run equal size tyres front and rear was removed. Toyota abandoned this specification on its 2022 update of the GR010 as a result of the changes to the minimum weight back in 2020, while Peugeot just snuck in before the new rule came into force. All LMDhs and new LMHs must run 13.5in tyres on 12.5in rims on the front and 15in tyres on 14in rims at the back.

“We had a series of technical meetings essentially based on simulation to anticipate an alignment of performance,” explains Vasselon. “Clearly the architecture of a LMH with four-wheel drive was a major difference. Item by item we went through all the performance factors that were different and somehow they have been aligned.”

What were believed at the time to be the final LMH rules were published by the FIA in December 2018. No one could have known at the time that they were in fact far from final

“Everyone understood the commitments the LMH manufacturers had made in developing all-wheel-drive vehicles, but a four-wheel drive and a rear-drive vehicle are two very different platforms,” says Hodgson. “For equitability of the competition we had to look at all those elements and try to do a lot of work to really evaluate the benefits of the different attributes of the different types of cars.”

Klauser – who remembers “lots and lots of meetings, lots!” — stresses that ensuring a level playing field between LMDh and LMH wasn’t just about speed over one lap. “The most important thing was parity,” she says, “and just because two different types of car can turn the same lap times doesn’t mean they are equal in a racing situation.” That hints at the LMDh manufacturers’ concerns about four-wheel drive.

The road to convergence – a term borrowed from the ultimately unsuccessful attempt by the FIA to bring GTE and GT3 rules together in 2012-14 – began a long time before Daytona 2020. The ACO and the FIA had set out to find a new set of regulations to replace LMP1 in the aftermath of Porsche’s shock announcement in July 2017 that it would be ending its involvement early at the end of that year. IMSA’s technical staff were involved in the process, from the roundtables that began in the spring through to the technical working groups that followed in the summer after the ACO and FIA’s vision for LMH was unveiled at Le Mans in June 2018.

What were believed at the time to be the final LMH rules were published by the FIA in December 2018. No one could have known at the time that they were in fact far from final. The idea of the ACO and the FIA had been to lower the financial bar to entry into the top prototype class, but in the spring of the following year a group of manufacturers – Ferrari, Aston Martin and McLaren – went back to the rulemakers arguing that they weren’t low enough. They also raised the idea of road-going cars going up against the pure-bred LMH prototypes. Aston, of course, took that route with its still-born Valkyrie project.

The demise of the Porsche LMP1 factory programme at the end of 2017 was the trigger for the WEC to seek a cheaper alternative

Photo by: JEP / Motorsport Images

The WEC had been bullish at the end of 2018 about its future with LMH. It was privately predicting five manufacturers would be on the grid by the end of the 2021-22 season. As 2019 wore on, it became increasingly clear such a shake-up was hopeful in the extreme. There were also doubts inside the WEC about Aston Martin’s commitment. Those ultimately came to pass, the British manufacturer blaming the LMDh announcement for its decision to put the project on what remains a permanent hold. It claimed that the new category undermined a business model based on the sale of customer cars.

The ACO and the FIA ultimately decided that they didn’t have a choice but to join up with IMSA on its plans for DPi 2.0, though of course they would never articulate the genesis of LMDh in those terms. IMSA was never likely to adopt LMH regulations, but its engagement in the rule-making process meant it took the idea of performance windows for aero and drag – easily attainable minimum and maximums to reduce costs that are at the heart of LMH – on board and adopted it as one of the building blocks for the new category initially aimed solely at North America. That definitely helped facilitate the convergence process a couple of years down the line.

Sportscar racing now stands on the brink of what so many are heralding as a golden age, though when the first LMH cars start racing across the Pond in IMSA remains unknown. But there is a confidence among the governing bodies that the convergence process will create the desired level playing field.

“The ACO, FIA and IMSA have been working in lock step with all of the LMDh and LMH manufacturers on the overall BoP process, on simulation and how the overall competition will be managed to ensure there is performance equity,” says Hodgson. “We stand by our statements that we expect every manufacturer will have an equal opportunity to win races and championships.”

LMDh cars replacing the outgoing DPi machines have attracted the likes of BMW to return to the prototype ranks

Photo by: Andreas Beil

The manufacturers committed to LMDh

Acura
The Honda brand announced it would be carrying on in IMSA with a new LMDh in January 2021. A North America-only brand, it has so far only committed to IMSA, where it will compete with single-car entries from Wayne Taylor Racing and Meyer Shank Racing in 2023. Its ARX-06 has been developed in conjunction with ORECA and is powered by a 2.4-litre twin-turbo V6.

Alpine
A full-scale return to frontline sportscar racing by Alpine as the Renault brand undergoes a relaunch was announced in October 2021. The car will be developed by ORECA, which produced the Gibson-engined A480 LMP1 design it has fielded in the WEC for the past two seasons. Signatech will again run what is a WEC-only programme from 2024, though customer cars could end up in IMSA.

BMW
BMW has partnered with Dallara for its return to the sportscar big time next year. The programme announced in June 2021 was for IMSA only with the Rahal team, though this was extended last summer to cover the WEC from 2024 with WRT. The engine in the back of the M Hybrid V8 a development of its DTM powerplant of 2017-18, now in turbocharged form.

Cadillac
The General Motors marque continues in IMSA and expands into the WEC for the first time with a continuation of its sportscar programme dating from 2017. Dallara is once again its chassis partner on the V-LMDh, the engine an all-new 5.5-litre normally aspirated V8. Chip Ganassi Racing fields the solo WEC car and one in IMSA alongside Action Express Racing. Expect all three to be at Le Mans.

Lamborghini
Lamborghini, part of the Volkswagen group like Porsche, has ended up ploughing its own furrow for its first top-flight sportscar entry. It has partnered with Ligier Automotive and is developing a clean-sheet twin-turbo V8 for the car. Iron Lynx will run a solo car in both the WEC and IMSA starting in 2024 in co-operation with sister team Prema.

Porsche
Porsche makes a return to the prototype ranks only five years after the end of its LMP programme with the 963 developed in conjunction with Multimatic and powered by a turbo engine with its roots in the RS Spyder LMP2. The factory Penske team will field two cars in both WEC and IMSA while there should be a further pair of customer entries in each series.

Porsche is well advanced in its testing with the new 963, the factory cars run by Penske

Photo by: Morgese / Gandolfi