Porsche is preparing a comprehensive overhaul for the new generation of the top-rung 911 racer.

The next-gen Porsche 911 RSR race car allegedly eschews the model’s venerable rear-engine layout for a mid-mounted setup, and the flat six reported boasts a biturbo layout for keeping up Ferraris and Corvettes at Le Mans. These details are just rumors for now, but we now at least know what the coupe looks like on track thanks to a spy video of testing from Sebring International Raceway. The new 911 looks fast and sounds great.

The rear provides the best evidence that Porsche is developing big changes for its top-rung 911 racer. There’s no window back there. Instead, where the driver would usually see out is a black panel with a bunch of louvers and intakes.

Porsche 911 RSR Rear

Rather than a center-exit exhaust on the current racer, the pipes are now more towards the corners, and there’s a massive diffuser in between them. According to Road & Track, the new design should produce far more downforce underneath the car and allow for less aggressive rear wing setting. It appears that Porsche’s engineers are still working on the final shape here because the black coupe in this video lacks part of the back of its fenders, but the piece is more complete on the white example.

Porsche rolls out 911 RSR successor for 2017

Porsche revealed the updated look for the RSR in May 2016, but the company has been very careful about not showing the back of the coupe. The firm also hasn’t released many official details about it. The track debut will happen in January at the Daytona 24 Hours. The race car will then likely compete in North America’s IMSA WeatherTech SportsCar Championship.

Spy shots from testing at Monza earlier this year gave us our first look at the RSR’s rear end. Compared to the current version, the intakes in the rear fenders are much larger. The need for so much cool air offers further evidence that there could be big powertrain changes for the race car.

Source: Road & Track

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Gallery: Porsche 911 RSR spy video