Porsche has produced a 4.2-litre version of its naturally-aspirated flat-six producing 456kW at a stratospheric 9400rpm – and it sounds absolutely berserk.
The storied German sports car maker previewed the sound of its new race-bred engine in the video below, where you can hear it reach for those rev-happy highs.
A track-only proposition for now, the new 4.2-litre flat-six is installed in the back of the 992 911 GT3 R Rennsport and ups compression, utilises specific camshafts and pistons and screams through an ear-splitting “unsilenced” exhaust system with two centrally-exiting tips.
The water-cooled engine is designed to run on E25 fuel, either bio-ethanol or Porsche's new renewably-manufactured eFuel. It can also run on conventional fuels.
Meanwhile there's a six-speed sequential dog-box, carbon clutch and mechanical limited slip diff, while inside is pure, functional race car.
Neither able to be road-registered nor homologated for any race series, the single-seat GT3 R Rennsport is instead a very expensive track day toy. Just 77 examples will be built at a cost of A$1.6m – making its price almost as lofty as its redline.
Porsche will sell the GT3 R Rennsport in seven colours and three different liveries, or in scintillating-sounding pure naked carbon-fibre. And if its straight-piped exhaust is too loud, Porsche can sell you your GT3 R Rennsport with mufflers and catalytic converters – to keep the neighbours beside your personal racetrack happy.
The big question now is whether the 9400rpm donk will make its way into a 911 road car. For now, watch and dream: