From pit-lane to fast lane: exactly how Porsche has fine-tuned the 911 GT3
How Porsche has fine-tuned the new 911 GT3
Every generation of 911 GT3 sets itself an extraordinary challenge: to offer the highest level of race-derived performance alongside Porsche’s trademark everyday usability. The new 992 model GT3, launched earlier this year, has raised the bar once again, combining the latest developments in series production sports cars with the hard-won technical know-how of its world-beating Motorsport department. As Andreas Preuninger, Director GT Model Line puts it: “When we have the same engineers who develop our race cars also working on the design of a new GT car for the road, that is the most direct technology transfer I can imagine.”
Where this technological progress is most apparent is in the area of aerodynamics. The new 911 GT3 is the first series production Porsche to be fitted with a suspended rear wing. Its swan-neck mounting is used in a similar form on the 911 RSR and 911 GT3 Cup cars, with two aluminium brackets now holding the wing from above to allow airflow to pass undisturbed beneath.
The 911 GT3 in the wind tunnel
“We developed the aerodynamics of the new 911 GT3 in around 700 simulations,” explains aerodynamics engineer Mathias Roll. “And we spent more than 160 hours fine-tuning the car in the wind tunnel.” The angle of the new rear wing can be set to four different positions, as can the adjustable front diffuser. “The new 911 GT3 generates 50 per cent more downforce than its predecessor at 200 km/h just in the ex-works setting,” adds Roll. “In the setting with maximum downforce, the increase is as much as over 150 per cent.”
As with a fully-fledged race car, the aerodynamic balance of the new 911 GT3 can be individually adapted to track conditions and individual driving style. “Not only are the components very similar to those used in our race cars, the development methods are also similar,” explains Roll. “In our ultra-modern wind tunnel in Weissach, we do not just drive straight ahead, we simulate every conceivable driving situation. We make the car roll, pitch and yaw in order to simulate the physical influences on the track.”
Porsche’s engineers have also spent a remarkable amount of time developing the car’s naturally aspirated engine. “In total, the engine in the new GT3 ran for more than 22,000 hours on the test rig,” explains Thomas Mader, Project Manager GT Road Car Engines. “During testing, we repeatedly simulated typical circuit profiles and ran the engine at full throttle for a very high proportion of the time.”
The free-revving 4.0-litre boxer unit is closely based on the race engine from the 911 GT3 R and is virtually unchanged from the those fitted to the GT3 Cup cars. Output is 10 PS higher than in the previous generation GT3, with maximum power arriving at an intoxicating 8,400 rpm (fuel consumption combined: 13.3 – 12.4 l/100 km; CO2 emissions combined: 304 – 283 g/km). Borrowing again from motorsport, the GT3’s precise valve actuation at high revs is delivered via rigid rocker arms. The proven VarioCam technology ensures camshaft control is adapted precisely to engine speed and load condition. A crankshaft with large bearing diameters, wide connecting-rod bearings and plasma-coated cylinder liners also ensures lower friction losses and reduced wear. “The individual throttle valve system is taken straight from motorsport and significantly improves responsiveness,” adds Mader.
And his team haven’t stopped there. The high longitudinal and lateral G-forces produced by the new 911 GT3 on track mean that correct oil supply is of vital importance. This is performed by a dry-sump lubrication system with separate oil tank. With a total of seven suction stages, the engine oil is routed back into the external reservoir quickly and efficiently, while lubrication of the highly loaded connecting-rod bearings takes place directly via the oil pump through the crankshaft. “The engine in our 911 GT3 Cup race car essentially differs in respect of just two components: the exhaust system and the engine control unit. Everything else is identical,” explains Mader.
The new 911 GT3’s engine was also put through its paces by our engineers and test drivers in real world environments beyond the bench testing initially performed in Weissach. “We conducted 600 emissions tests during development in order to meet the strict standards,” says Mader. Similarly stringent testing was also applied to the engine's endurance capabilities, most notably with a continuous run of over 5,000km around the famously unforgiving Nardo Ring in Italy. The car was tasked with maintaining a constant speed of 300 km/h, stopping only to refuel, and was able to perform the task flawlessly. One more box ticked on a long and exacting list.
911 GT3: fuel consumption combined: 13.3 – 12.4 l/100 km; CO2 emissions combined: 304 – 283 g/km