The four LMDh manufacturers whose cars will make up the GTP class in the IMSA WeatherTech SportsCar Championship have been logging a lot of miles in preparation for the season-opening Rolex 24 At Daytona next month. Thousands of laps have been turned at a variety of tracks, including Daytona International Speedway, where all four gathered for an IMSA-sanctioned test last week. But those miles have not all been trouble-free.
LMDh cars are complex compared to their DPi predecessors, and aside from the supply chain problems plaguing everyone in trying to assemble cars and all the spares needed for the Roar before the 24 and the Rolex, getting everything working together — the spec hybrid system, the internal combustion engine, the brake-by-wire systems and the processors that tie them all together — hasn’t always been easy.
“On a scale of one to 10 the steepness is about 12 or 13,” says Maurizio Leschiutta, LMDh project leader for BMW M, of the learning curve. “Sometimes I feel like Sisyphus rolling a rock eternally up a hill to have it roll down again. We have faced some major challenges, principally because of the time frame. We went from a white sheet of paper to the first race — which is also a grueling 24 hours — in 18 months. And this has posed a lot of challenges to our teams, our partners, which made for a lot of work. We use all the competencies of BMW Motorsport across our different departments involved not only in GT racing, Formula E and so forth. We have been putting everybody’s head together to contribute to this program, which is the priority program for BMW M Motorsport now.”
Even Porsche, which has experience building hybrid race cars in the 919 LMP1 car that competed in the World Endurance Championship and won at Le Mans, has found some unique difficulties. Porsche had a head start with its 963, but that also meant their car was the guinea pig for getting the spec hybrid system — which includes components from Bosch, Williams Advanced Engineering and Xtrac — all working properly, explains Porsche’s director of factory racing, LMDh, Urs Kuratle.
“The biggest challenge is getting all the different parties on the same table and working seamlessly,” says Kuratle. “I think all (the manufacturers) have all the parts in the right configuration, the same software, all those things. We have to bring that program together because all of us, I believe, are used to high-level motorsport programs. But most of them probably had less different parties involved. Now we have Bosch, we have Williams, we have Xtrac, we have our teams who are operating those things. I believe that makes it quite complex, at least from the Porsche point of view.”
For those who haven’t worked with hybrid racing powerplants before, there’s a whole new level of challenge. BMW has plenty of experience with both ICE and electric motors, but this is the first time the two have been combined in a BMW Motorsport program.
“We have a lot of partners working together — and I call them partners rather than suppliers, because we are in it together,” says Leschiutta. “We have our guys here and BMW Motorsport have experience with Formula E. This is useful, precious information that we can transfer over. For us, it’s the first time that we combine this electrification technology with classic internal combustion engine, so to make these two very different animals work together poses its own challenges. But aside from that, everyday is a school day. And we’ve been learning every day.”
While competitors, the GTP manufacturers have had to share some of the load in getting all the hybrid components up to speed. Michael Levitt/Lumen
Laura Wontrop Klauser, sports car racing program manager for General Motors, echoes that sentiment. Cadillac had a lot of success with it’s DPi.V-R, but the V-LMDh is a different animal that requires new resources to throw at it.
“We cannot have enough software engineers working right now on all the different things because everything in the car is connected. Things that we never had to worry about influencing each other in the past with the DPi or other race programs … now if one thing is slightly off, nope, not gonna run,” she explains. “Or it’s not going to turn or brake or whatever it needs to do. So it’s the importance of making sure that all the calibrations are correct. And then the safety critical component of that to make sure that everything’s correct is huge. So that’s been probably the biggest mountain, is working through all of that once we have the parts that get on the car to test. This whole program has been fun, but it’s been a big challenge.”
As it all comes together, there are sometimes unintended consequences. Some of it, as Klauser noted, is the bad kind that leaves cars idle when they should be going. Other surprises may lead to new developments for road cars. And sometimes, it just produces something that’s kind of cool. One example of the latter: The Acura ARX-06 makes a very unique noise under braking for a slow corner.
“That’s the fun of these cars — they are the future, they’re pretty cool,” explained David Salters, president of Honda Performance Development that’s developing the Acura LMDh car. “We are trying to brake, we are trying to regen — you know, generate energy charge the battery, we’re trying to do engine braking, we’re trying to manage the brake-by-wire system. All that apparently makes a weird noise. We’re also we’re trying to protect some of the parts as well. You don’t want the driveline to oscillate and all that sort of stuff.
“When you’re doing these things, you need to program events so that we don’t damage parts. So all that conspires — that whole confluence of engine braking and regen and sort of just trying to manage the car into the corner with the electrification and all the other bits — it ends up making that noise, which is quite cool, isn’t it? I’d like to sit here and say, ‘Oh, well, it’s deliberate.’ It’s basically as we manage our energy through the corner at the moment, and it probably will change. But it sounds awesome.”
Fans will have their first opportunity to hear the ARX-06, along with the BMW M Hybrid V8, Cadillac V-LMDh and Porsche 963, at the Roar Before the 24 on Jan. 20-22 that precedes the Rolex 24 At Daytona the following weekend.