The Porsche Penske Motorsports team has started active testing of its new hybrid LMDh prototype and confirmed the powerplant for the Multimatic-built chassis. As RACER has documented for more than a year, a twin-turbo V8 has been developed to propel the LMDh models commissioned by the Volkswagen Group, which includes Audi and possibly one more brand within the company.
“We were spoiled for choice with the engine for our LMDh prototype, because the product range offers several promising baseline units,” said Porsche Motorsport VP Thomas Laudenbach. “We decided on the V8-biturbo, which we feel offers the best combination of performance characteristics, weight and costs. The kick-off to the active test program was an important step for the project.”
Although Porsche did not detail the displacement or origins of the engine, it’s believed to be based on the brand’s 4.0-liter twin-turbo V8 motor found in the Cayenne SUV. From the image shared by Porsche, the motor uses the increasingly popular “hot V” configuration, with the exhaust and turbos placed atop the engine and the air intakes fed through the sides of the heads. Coupled with a 40hp energy recovery system that is required in every 2023 LMDh, the combined power output for the class is targeted at 680hp.
“The engine regulations for the LMDh vehicle class allow a great deal of freedom in terms of displacement, design and number of cylinders,” Porsche wrote. “Maximum revs are 10,000 rpm, with the pass-by noise measurement capped at 110 decibels. The engine must weigh a minimum of 180 kilograms (397 pounds), including the air supply and exhaust system as well as the peripheral cooling components. If used, this weight also incorporates the turbocharger’s, including the charge air cooling.
“In line with the regulations, the maximum output lies between 480 and 520 kW (644 to 697hp). This range also allows adjustments to be made within the Balance of Performance parameters, which are intended to ensure parity between all competing LMDh racing cars. The torque curve is also clearly defined.”
Following a successful first test of the car at its Weissach track in Germany, Urs Kuratle, Porsche’s LMDh project manager, is confident their engine choice is the right one.
“The rollout of the LMDh racing car was also the first track outing for Porsche Penske Motorsport,” he said. “The squad worked well together right from the start. This shows a high level of professionalism in all areas. After all, the operational requirements for the safe running of a hybrid vehicle are very high. In the next outings we will focus on going deeper into the required processes and procedures. During these first test days at Weissach, the V8-biturbo impressed us in every respect. We’re convinced that we’ve chosen precisely the right unit.”