Yahoo Autos The New Hybrid GTP Hypercars Bump-Start Their Engines by Dumping the Clutch at Speed
You’ve seen the video Cadillac Racing released weeks ago, teasing its 2023 LMDh prototype race car. Once the music fades, the soundtrack is replaced with what sounds like an amplified RC car, screaming. It’s the sound of the Cadillac’s hybrid system working as the car takes off from the pit box under pure electric power. Just seconds later, your eardrums boom with the roar of the car’s naturally aspirated 5.5-liter V8 coming to life. In a vehicle with an enormously complex hybrid drive system, you’d assume the transition from electric to gas power would be a complicated dance. But the mechanics behind it are as simple as dropping the clutch.
Every car in the new-for-2023 Grand Touring Prototype class is required to utilize the same hybrid powertrain: a 1.35-kWh battery pack by Williams Advanced Engineering, a 50-kW electric motor-generator unit by Bosch, and an Xtrac gearbox. Each automaker in the GTP series — currently Acura, BMW, Cadillac and Porsche — designed and developed its own internal-combustion engine to pair with the spec hybrid system.
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Things get complicated when you pair a brand-new, complex hybrid system with a variety of internal-combustion engines. For starters, if the hybrid system isn’t working, the car won’t work either. Jonathan Diuguid, Managing Director of Porsche Penske Motorsport, explained to me at Daytona that the car relies solely on the hybrid system to generate electrical power. “None of the cars out there have alternators. They’re all generating power through regen,” Diuguid said. Without an alternator or conventional starter, the GTP hypercars utilize the battery, along with the gearbox-mounted MGU, to get the car moving and make the transition to combustion engine power. The problem is, if the hybrid system isn’t working, the internal combustion engine won’t work either, and the car will be bricked.
