Cadillac is one of many automakers trying their hand at building a championship-winning LMDh car. The rules for the latest generation of these machines are wide open. Every company competing, from Ferrari to Toyota, has a different idea in terms of how to get the job done. Cadillac's is unique, though. It's the only naturally-aspirated cross-plane crank V-8 on the grid. This makes its noise loud and instantly recognizable.
The American brand is keen on making this fact known to everyone. A new video on its YouTube channel highlights the sound of the car, known as the V-Series.R, and goes into detail about why the engine sounds the way it does, and how it's assembled.
Known as the LMC55R, Cadillac's V-8 has more displacement than all of its competition. It sits at 5.5 liters, making it more than twice the size of the Acura ARX-06's 2.4-liter turbocharged V-6, for instance. As per the regulations, all of the engines make the same power when combined with a spec hybrid system—even the power curves must be very similar—but there are almost no restrictions on the exact configuration of the engine itself. This lack of regulation around engine type led Cadillac to go for a relatively unique design.
In contrast, how the cars must crank over their engines is heavily regulated. Starter motors are explicitly banned, meaning rolling out on electric power and bump starting are necessary to get the job done. The American car, in terms of the soundtrack, excels at this.
Several other entries on the LMDh grid sound great too, but Cadillac has gone to extensive lengths to promote the car—and its exhaust note—as a part of its brand. It's released a handful of short videos similar to this in the past, let one of the vehicles drag race against a roadgoing Ferrari, and even had a full documentary made about its podium-winning Le Mans debut in 2023. Needless to say, Cadillac and General Motors take the whole program very seriously. Let's hope it translates into more exciting road cars.
