Insight: Behind the Scenes at a Porsche LMDh Test

Sportscar365's Daniel Lloyd provides inside look from multi-day test at Spa-Francorchamps...

2022 is the year of the LMDh and LMH track test. With six manufacturers working on new sports prototypes for next year, and Peugeot aiming to be on the FIA World Endurance Championship grid later this season, it’s hard to recall such an intensive period of development and validation at this level of the sport.

However, manufacturers usually only trickle out a few small details about what actually goes on at these tests.

Based on what the major OEMs with track mileage under their belts have revealed, some photos will be posted on social media, and we might get some basic information about the weather conditions, who drove the car and so on.

But this only scratches the surface.

Last month, Porsche invited Sportscar365 to attend one of its LMDh tests, giving the opportunity for a rare behind-the-scenes look.

This was the third track run for the unnamed Multimatic-based prototype, which is so far the only LMDh to have turned laps.

The Spa run followed on from five days at Barcelona and three days at Motorland Aragon, with quick rollouts at Porsche’s Weissach facility sprinkled in between.

The experience was a refreshingly detailed look into the testing process: how Porsche allocates its time, what issues it encounters and how it works with the LMDh spec parts suppliers Bosch, Williams Advanced Engineering and Xtrac to double as both a competitor and a mule for the formula.

The Spa test lasted three days and took place in dry, chilly conditions. This was pleasing for the Porsche Penske Motorsport team which, at Aragon, had encountered persistent rain.

We joined them for the middle day when Dane Cameron drove in the morning and Felipe Nasr took the afternoon. Fred Makowiecki drove on day one, while Laurens Vanthoor and Andre Lotterer joined on day three: their helmets awaiting them in the pit garage during our Wednesday visit.

A nine-hour running window from 9 a.m. to 6 p.m. was permitted each day. Porsche didn’t fill that time with track activity: there was plenty of sitting in the garage, drivers talking to engineers about various car settings.

A major part of the test was gathering data for Michelin, which had brought two service trucks and two mobile offices. As the sole supplier for LMDh and LMH, Michelin has been eager to work with Porsche to validate its product.

“We did tire testing in Aragon,” said Urs Kuratle, Porsche’s Director of Factory Motorsport LMDh, at the end of Wednesday’s running. “Probably about the same amount as Spa. In Aragon it was raining quite a lot, so we did wet tire testing which Michelin very much appreciated. Here it was dry tire testing. It’s quite a lot of work.

“But before you do tire tests, you first have to get the car in a proper window to learn anything. That was the main goal yesterday. We are still testing the car and trying to find out the windows where the car is working best in terms of weight distribution, aero balance etc.

“Tire testing was also yesterday, but it was compromised by some technical issues we had. Actually, it was the first day in which we did not finish the test plan as we wanted; the first day that did not go according to plan.”

The sensor-based gremlins appeared to have dissipated by day two, but Kuratle noted that some driver ergonomic problems then sprung up.

This is all a normal part of the process and, despite having the most advanced development schedule, Porsche is still at a very early stage on its pathway to LMDh homologation. Nothing is perfect. If they considered everything to be so at this stage, then something will have been overlooked.

The added implications of Michelin wanting to gather tire data and the common parts suppliers wanting to bring updates to each test means that Porsche has been simultaneously working on its own car and doing legwork for the whole LMDh platform because all manufacturers are using the same tires and hybrid system. The process therefore requires a degree of patience.

“It’s a balancing act between the work that we need to do from the Porsche car side, and then some of it is just tire work for Michelin which is more category-related, and proving some systems stuff on the battery,” Cameron explained.

“It’s not really for us. It’s good because we get mileage on it: we get to see it and understand it. So it helps, but it’s not as if we’re pounding around doing 8,000 car changes and balance changes every day. It’s an hour or two of car work, an hour or two of systems, this and that.

“You try to divvy up the day to get through pieces of everybody’s program. Sometimes you have to shift it based on the weather. We had quite good weather at Spa.”

Track conditions, however, were dusty. Some of that was due to the wind wafting earth from the massive quarry-like infrastructure work at Spa onto the surface. A Porsche Experience Day for road cars took place shortly before the test, but Kuratle said this wasn’t enough to properly prime the track for the LMDh.

It’s also early in the year for the circuit: conditions will be better once a few races have taken place, but availability isn’t always there so a compromise is needed.

In the hybrid LMP1 days, Spa was always a battle of aero kits as manufacturers weighed up whether to use lower or higher downforce options for the two fast sectors and one twisty part in the middle. LMDh and LMH manufacturers must use a single downforce configuration, which brings its own challenges. Learning how to work around this was another key part of last month’s test.

“We like what we saw on the data from the car,” Kuratle said. “The drivers always have their opinions on what could be, and will be, better. We are happy to have that feedback. Being in the early stages, we are checking power steering and finding out aero influence, to give the driver the best feeling through the very special corners at Spa.

“There is a lot of improvement we have to do and will do on the car to make the drivers happy. But again, it’s early days in the program. The aero maps are, by rules, quite limited. It’s the nature of the LMDh project: you cannot do completely what you want.”

Viewed from trackside, the Porsche looks fast but also very steady in its movements. Maybe that’s because the team hasn’t yet moved on to locating its peak performance (there was a hint of a lift at Eau Rouge). But as Cameron noted, this car is 100 kg heavier than the current-generation DPi prototypes. Sound-wise, there were lots of interesting whirrs as Nasr flicked the car right, left and right through Les Combes, the hybrid system working hard.

Porsche’s twin-turbo V8 engine, the displacement of which hasn’t been disclosed but is known to be large, sounded great up close but admittedly not as loud as a noise-restricted GT3 car that it was sharing the track with. In the pits, Porsche rolled out the LMDh on electric power – something it can’t do in competition – which enabled us to hear the V8 engine crack into life halfway down pit road. That one brought the goosebumps.

The Porsche Penske Motorsport garage was a hub of data: about six long rows of engineers from the U.S and Europe poring over graphs and numbers, each using multiple monitors. The setup corresponded to the complexity of LMDh cars, despite their spec-hybrid nature, according to Porsche Penske Motorsport managing director Jonathan Diuguid (pictured above).

“I think the biggest thing is that modern prototypes are getting more complicated, not less complicated,” he said.

“There are a lot of different systems that have to talk together for the car to function properly. To control the temperatures, we have lots of thermostats. We’re exposing the car to a variety of conditions and making sure it’s consistent over that variety. And exposing mechanical failures or electrical failures with the hybrid system.

“The focus is flushing out the mechanical bugs to have a reliable car to run, and then understanding the systems, electronics and software to have a car that also performs well.”

Performance-based testing will be gradually ushered in later this year, when Porsche also starts ticking off the homologation criteria for its 2023 race debut competing against the likes of BMW, Cadillac and LMH marque Ferrari.

Those other manufacturers are yet to roll out their new cars, but once they do there will be similar processes of identifying issues, scanning setups and building tire data that were among Porsche’s tasks at Spa.

Simultaneously, Porsche’s responsibility of being an LMDh test mule will progressively fade away and be superseded by a more competitive, individual performance focus.

The manufacturers will then convene at two IMSA sanctioned tests in October and December, ready for their debut at the Rolex 24 at Daytona in January to spur an exciting new chapter for top-level sports car racing.

The period leading up to that is a time of validation: discovering how the months and years of hard office-based work translate when each car fires up and hits the track.