The Porsche 918 Spyder won't officially be unveiled for another couple of months, and in the meantime the German automaker is deep into the planning phase of its upcoming Ferrari fighter. Currently dubbed the 960, Automobile magazine is reporting that Porsche has recently made some changes to the car's make up, which was originally rumored to be powered by a mid-mounted 4.0-liter flat-six. With that engine ruled out, Porsche is apparently replacing it with an all-new quad-turbo 3.9-liter flat-eight.

All told, it could have an output in the neighborhood of 650 horsepower. Why did Porsche give up on the more traditional flat-six option? Sources claim that such an engine would push the car's asking price into Ferrari F12 Berlinetta and Lamborghini Aventador territory, both of which have V12s. Along with its four turbochargers, the new flat-eight will come equipped with twin intercoolers, four adjustable camshafts, a multistage intake manifold and a dual-stage exhaust system. The 960 will retain its mid-engine setup and the new engine will sit low in the chassis for a lower center of gravity.

The new chassis itself will share architecture from future VW Group performance models such as the next-gen Boxster and eventual Aventador replacement. Constructed mainly from aluminum, steel, carbon fiber, magnesium and titanium, curb weight should tip the scales at around 3,000 lbs. Production, however, isn't set to begin until 2017.