The 992-generation Porsche 911 Turbo is nearing production readiness, with the German sports car maker itself releasing images of pre-production examples undergoing development exercises in Nice, France. Our spy photographer sources have also spotted the forthcoming Turbo around the Nurburgring area, likely in preparation for circuit testing at the famed Nordschleife.

Porsche works driver Jörg Bergmeister has also been photographed alongside what appears to be a 992-generation 911 Turbo Cabriolet, the drop-top development car pictured here wearing the wheel design from the 991-generation Turbo S Exclusive. This, like its fixed-roof twin, looks all but ready for production.

So far, we know that the next 911 Turbo will be powered by a 3.8 litre twin-turbo flat-six engine in both its standard and Turbo S forms, the latter possibly producing up to 650 PS and 800 Nm of torque in the latter and at least 600 PS in standard Turbo guise, according to Car and Driver. With its most potent powerplant, the Turbo S should gain on its 0-100 km/h time and top speed of 2.9 seconds and 330 km/h respectively.

The 3.8 litre biturbo flat-six in the Turbo S is largely unchanged, save for updates to its cylinder liners, exhaust manifold and fuel injectors, as well as larger turbochargers. The BorgWarner variable geometry turbochargers now feature larger housings on both the exhaust turbine and intake compressor sides and intercoolers have been relocated from behind the rear wheels to directly above the engine.

Meanwhile, the catalytic converters are redesigned for less back pressure and improved flow and an optional sport exhaust alters both exhaust volume and sound, a 911 Turbo first, according to the website. More power also means more heat, therefore Porsche have also developed further measures for the 911 Turbo to be able to reject the additional thermal load, comprising new heat shielding, updated materials, additional cooling air channels above the hottest components and two electric fans.

Building further upon equipment in current 992-generation models, the 911 Turbo and Turbo S are said to also incorporate an eight-speed dual-clutch automatic transmission as the sole gearbox choice, using the same ratios as those in the 911 Carrera but with a new final drive ratio for the Turbo S to attain its top speed.

The rear limited-slip differential is electronically controlled while the centre differential is a hydraulically controlled limited-slip unit, and the front differential is a conventional, open item. The 911 Turbo S gets Porsche Active Suspension Management with two modes – Normal and Sport – as standard, including rear-wheel steering, while an optional sport suspension setup the car by 0.8 inch (20.3 mm) from the base Turbo and 0.4 inch (10.2 mm) from the standard Turbo S setup.

The increased engine outputs are also supported by larger rolling stock on the 992-generation Turbo S, now with staggered wheel diameters. These now comprise of Michelin Pilot Sport 4S tyres which measure 255/35R20 in front and 315/30R21 at the back, housing 419 mm carbon-ceramic front brake discs with 10-piston calipers, while the rear axle gets 391 mm brakes.

The Porsche 911 line-up has historically spanned a wide range of versions, with the Turbo and Turbo S assuming the supercar-chasing role among its conventional model range stablemates outside of the Motorsport department GT models. What do you think, folks? Looking forward to the latest iteration of the 911 Turbo and Turbo S?

GALLERY: 992 Porsche 911 Turbo spyshots

GALLERY: 992 Porsche 911 Turbo Cabriolet spyshots