Porsche has commenced the active testing phase for its Le Mans Daytona hybrid (LMDh) prototype endurance racing programme in the FIA World Endurance Championship (WEC) and the North American IMSA WeatherTech SportsCar Championship (IWSC), both of which the manufacturer will be contesting under the Porsche Penske Motorsport banner.

In its choice of internal combustion engine, Porsche has chosen a “large-capacity twin-turbo V8 unit” to be paired with a standardised hybrid drive system as stipulated in the technical regulations for this category, in which teams are allowed to design their own engines and bodies for pairing with chassis produced by approved suppliers, which is Multimatic for Porsche’s LMDh effort.

This engine for the LMDh race car has been designed to run on renewable fuels, which is aimed at achieving a “significant reduction” in CO2 emissions compared to traditional fossil fuels.

Porsche has been researching synthetic fuels for its internal combustion engined cars and has earmarked motorsport for its first application; the 2021 Monaco GP round of the Porsche Mobil 1 Supercup saw the race debut of Esso Renewable Racing Fuel with the premiere of the 992-generation 911 GT3 Cup race car.

“We were spoiled for choice with the engine for our LMDh prototype, because the product range offers several promising baseline units. We decided on the V8 biturbo [engine], which we feel offers the best combination of performance characteristics, weight and costs,” said Porsche Motorsport vice president Thomas Laudenbach.

Current Porsche models featuring a twin-turbocharged V8 engine include the Cayenne Turbo and Panamera Turbo S, producing 550 PS and 770 Nm, as well as 630 PS and 820 Nm respectively. According to Porsche, engine regulations in LMDh allow for an 11,000 rpm rev limit, with a drive-by noise limit of 110 dB, though the actual displacement of the LMDh engine was not specified.

The engine must weigh a maximum of 180 kg including intake, exhaust and cooling components, as well as turbochargers and charge air cooling if applicable. Maximum engine output will be between 653 PS to 707 PS, which may be altered according to balance of performance (BoP) parameters to aid parity between competing LMDh-class cars.

Total system output from the hybrid powertrain is 680 PS under racing conditions, says Porsche. In terms of driveline components, the battery is provided by Williams Advanced Engineering, the motor-generator unit and control electronics by Bosch and transmission by Xtrac.