Yes, a Penske run Porsche 917/10.
The car was capable of about 1200hp, although it didn't race with that much boost. The 73' Version 917/30 has been rumoured to have hit 1800hp on the dyno!!!!!
Yes the car says Porsche/Audi, as the companies had closer ties at the time. Specifically this was a program to market the Porsche 914's.