The new GT3 RS is the most powerful naturally aspirated 911 Porsche has ever built. But with rumors suggesting the next-generation model will be turbocharged, it also seems like a swansong for sublime-sounding naturally aspirated 911s. There's no need to worry however, because they’re here to stay for the foreseeable future. In an interview with Motor, Thomas Mader, Project Manager GT Road Car Engines, said “there will be a future” for natural aspiration when asked about the next-generation GT3 RS being turbocharged.
He went on to say it should still be possible to make naturally aspirated engines more fuel efficient to eliminate the need for forced induction. When asked if the current 4.0-liter unit will be the last, he replied “I don’t think so.” He also admitted that it’s possible to increase the engine’s displacement beyond its current 4.0-liter capacity but added that “the engine designers would have to look at that.” An increase in revs is more likely to happen in a future model, however, implying that the ultimate naturally aspirated 911 road car is still to come. The existing flat-six powering the 911 GT3 RS revs all the way up to 9,000 rpm, but Mader said a higher redline is technically possible.
The engine inside the road-going model is nearly identical to the ones in the mid-engined 911 RSR, the 911 GT3 Cup, and the 911 GT3 R race cars. In the RSR, the engine can rev up to 9,500 rpm. But while it’s technically possible, it would require some radical changes to the 911 GT3 RS. For [the new GT3 RS], [9000rpm] is matched perfect to the whole system,” he said. “Now I have to speak to my colleagues and we will have a car, and we will have 9500 revs, and matched to that all to the gearbox, then we will work on that technical side, which should be possible ... but [although] we have that engine for the racetrack, the lifetime aspect for road car is different."
If it does get the green light, a street-legal with a redline of 9,500 rpm would be one of the highest-revving production cars ever made, surpassing hypercars like the 918 Spyder, which revs up to the 9,150 rpm of and the LaFerrari, which revs up to 9,250 rpm.