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BMW Hybrids riding performance wave in IMSA and WEC

All of a sudden, things are looking up for BMW’s M Hybrid V8 program on both sides of the Atlantic. With a second-place finish in the WEC race at Fuji and a 1-2 in the IMSA Endurance Cup round at Indianapolis, both WRT and RLL have found form at the same time.

Two races remain in 2024 — IMSA’s Petit Le Mans and the WEC’s 8 Hours of Bahrain — and they appear crucial for BMW as it sets its expectations for 2025. Are we witnessing a turning point, like the latter part of 2023 was for Porsche Penske Motorsport, or will this month’s results prove a flash in the pan? BMW believes it’s doing the right things to make it the former.

Either way, the standout September for the German brand’s top-class sports car program has been a long time coming. Prior to Indy, RLL had been fighting through a sophomore slump in IMSA GTP, with zero trips to the podium through the first seven races. WRT, meanwhile, had also been waiting for a breakthrough before arriving in Japan, after spending much of its maiden Hypercar campaign playing catch-up with its new package.

So, what has changed? According to BMW, what we are seeing are the results of incremental updates to the car.

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In the current era — with manufacturers desperate to keep budgets under control — once an LMDh like the M Hybrid V8 is homologated, your options to take strides in performance and reliability terms are limited. The rule-makers must approve all updates and any changes to improve a car’s raw speed are unlikely to be granted as Balance of Performance — in theory — serves as a backstop.

As a result, manufacturers must develop their cars through marginal evolutions rather than frequent major updates and tread carefully when deciding which areas to spend their “Joker” tokens on. In both the WEC and IMSA, ensuring your car can look after its tires and maintain a steady pace over multiple stints is the key to success.

And that’s exactly what BMW has done with WRT and RLL over the past two years. Like the other LMDh manufacturers, when it comes to bringing evo Jokers, it has been apprehensive. But that doesn’t mean it has been twiddling its thumbs.

Andreas Roos, the head of BMW Motorsport, told RACER last month at Circuit of The Americas’ Lone Star Le Mans weekend that no major updates were in the pipeline. Instead, BMW has an off-season test plan mapped out and will stick with what it has for 2025.

“We are not where we want to be but there is room left in our package,” he said. “So we are trying to optimize this.

“The performance has spiked, like at Le Mans. So we know the potential is there, we just have to be more consistent and quick under all circumstances. But it’s clear with all these manufacturers that it’s not that easy to make steps.”

JEP/Motorsport Images

That begs the question: where exactly are the gains being made? According to Valentino Conti, BMW’s head of track engineering, much work has gone into fixing vibration issues that impacted a number of areas through the first season of the M Hybrid V8’s life.

He reveals that a change in engine concept from the current P66/3 eight-cylinder turbo (based on the DTM unit used in 2017-18) was even considered at one stage. But, like Porsche, BMW has decided to stick rather than twist, holding off on a major change. It’s also understood that developments from Bosch — the hybrid unit supplier for all LMDh cars — have made a big difference in this area and played a part in both BMW and Porsche’s decisions.

“We have had vibration issues not only affecting the hybrid system, but various other parts on the car,” he says. “We did a thorough analysis and we were thinking of a change (like Porsche) on the engine concept, but we identified all the areas and found solutions, which means we can stick to the concept.

“We never had many issues with the MGU; it was other parts of the car where we had issues that we had to fix. One part was the steering wheel. We were analyzing vibrations in the whole car, and one part was the steering wheel.”

Software is another area in which BMW has made progress with the M Hybrid V8. The complex systems behind the current set of LMH and LMDh cars can be tweaked and refined pretty freely. And, as Conti explained, there’s far more to it than just updating the car’s traction control.

“TC is one part for sure; you can always work on that and improve, and that’s critical for us,” he says. “But there are other functions on the car that you want to develop. You can influence the balance and also its performance under braking because it’s hydraulic, it’s in combination with the hybrid system and the re-gen. You want to play with these areas.

“You also have a power curve which you have to follow and with vibrations and oscillations, and it’s very hard to match the power. Sometimes, you overshoot, you undershoot, and you have to work out the margins and reduce them. Software never ends.

“And on this car, opposite to Formula E, it’s very aero-driven, and this is where we have to learn. The aero is frozen but you have to find the optimal window to run the car on the track and the differences here are the three types of tires and sometimes it’s not clear.”

Managing tire warm-up is a critical part of the performance equation in both IMSA and WEC. Michael Levitt/Motorsport Images

As BMW and its teams have learned more about the M Hybrid V8, they have found ways to improve tire warm-up, too.

With no tire warmers in either IMSA or the WEC, every manufacturer has had to find ways to get their cars up to speed as quickly as possible after each pit stop, to avoid bleeding away time on out-laps. There is still room for improvement in this area, though.

“Tire warm-up is a big thing,” Conti stresses. “With LMH and LMDh, there are differences because they have the MGU at the front and when they get away they can spin the front wheels, so for us bringing the front wheels up to temperature is still a struggle. And that’s not the only advantage.”

So while no evo Jokers are expected anytime soon — in part because the M Hybrid V8’s reliability is “knock on wood, OK” and in a “stable window” according to Conti — there’s cause for optimism. There is the belief that this uptick in form from BMW can and will carry over to the 2025 season, where expectations will be even higher.

Will we see BMW challenge for titles and major race wins at Daytona, Sebring and Le Mans? Taking that step, according to Roos, is going to take “something from everyone to give the drivers what they need to be consistently fast.”

Story originally appeared on Racer