Porsche, BMW raise concerns about high voltage issues…

Porsche and BMW have voiced concerns over the reliability of the high-voltage element of the one-make LMDh hybrid system going into this weekend’s Daytona 24 Hours.

Their apprehension follows a spate of issues that have afflicted LMDh machinery and forced parts to be changed over the course of the pre-event Roar test last weekend and the opening two days of the IMSA SportsCar Championship curtain-raiser at Daytona this week.

BMW M Motorsport boss Andreas Roos described the problems, which prevented the #25 Rahal M Hybrid V8 for setting a qualifying time on Thursday, as “a bit of concern”.

“Clearly it's not what you want to have in qualifying that the car stops on track,” he said.

“At the end you always feel better when there's no issue at all happening in practice and testing.”

Porsche 963 programme boss Urs Kuratle said: "I hope it's not a pandemic.

“I don't know the total number of changed batteries but it's definitely too many, that's for sure.

“From the reliability point of view, it looks like we did a step backwards compared to last year.”

#25 BMW M Team RLL BMW M Hybrid V8: Marco Wittmann, Sheldon Van Der Linde, Robin Frijns, Rene Rast (Photo by: Andreas Beil)

Porsche Penske Motorsport managing director Jonathan Diuguid added that the issues meant that the German manufacturer’s factory team is “not sitting here with a nice fuzzy feeling about the race”.

Porsche revealed that on Friday afternoon it had met with representatives from the other LMDh manufacturers, IMSA, and Bosch Motorsport and Fortescue Zero (formerly WAE Technologies), which respectively produce the motor generator unit [MGU] and the high-voltage battery components of the spec hybrid system.

Kuratle explained that there is “a big push here at the track and the home bases [of Bosch and Fortescue] back in Europe” to try to overcome the problems.

Diuguid added: “We are doing everything on our side to make sure we understand the problem and what we can control, trying to work with the suppliers to get their input and feedback on what might be causing the issue, trying to tick as many boxes as we can.”

The manufacturers have not revealed how many occurrences of the HV issue there have been so far, but Diuguid stated that in Porsche’s case it was “more than one”.

The first appears to have been in the second session of the Roar last Friday when the #7 Porsche 963 LMDh stopped on track with Felipe Nasr at the wheel.

The customer 963s run by JDC-Miller MotorSports and Proton Competition are also understood to have run into HV issues during the Roar.

BMW is known to have experienced HV issues on both its Rahal-run cars, though it is unclear whether Acura, Cadillac and Lamborghini have been afflicted.

Diuguid revealed that the issues were “not always the same problem”.

“It hasn’t been tracked back to a certain batch, a certain production run or a certain set of conditions,” he said

Kuratle stressed that the finger of blame should not be pointed at the battery.

“It is difficult to define the battery, where does it start and where does it finish? It is an HV issue,” he explained.

It is unclear why the hybrid issues have arisen at this point because the components proved reliable in their second season of the GTP era in 2024.

Diuguid explained there have been no updates for the new season, but admitted that “there are small variances that are normal”.

“There are some new pieces, a [different] production batch,” he said.

IMSA has been contacted for a comment.