Next-gen Porsche 911 GT3 tipped to use 4.0-litre flat-six

The new 911 Speedster’s heavily revised 4.0-litre flat-six engine will be carried over to future GT models  as Porsche’s GT division persists with naturally aspirated engines. 

GT boss Andreas Preuninger said: “We’ve invested in the future with this engine. I can’t comment on future projects but we would be stupid not to re-use this engine somewhere. 

“Our philosophy in GT cars is to stay naturally aspirated. We want to keep that engine for the future and that’s why we’ve made such a tremendous effort to get the engine right without taking emotion and performance away.”

Preuninger declined to reveal which models would use the updated engine, but a strong likelihood is the next-generation GT3. Recently spied prototypes at the Nürburgring Nordschleife emitted the tell-tail wail of a high-revving engine free from turbocharging, adding further weight to the speculation. 

The Speedster, a swansong for the 991 generation of the 911 priced from £211,599, uses the same powertrain as the outgoing GT3 but receives a host of updates. 

Chief among the updates, and in order to extend the regulatory life of this big-capacity direct-injection flat-six, Porsche has fitted two sizeable petrol particulate filters – one integrated into the exhaust tract that exits each side of the block.  

And yet owing to the use of thinner steel, nickel and soldering techniques rather than welding, the exhaust system now weighs 10kg less than before, despite the additional hardware. Power has also increased, from 493bhp to 503bhp, and continues to arrive at 8400rpm.

To achieve this increase with an engine that is not only cleaner but also suffers from an increase in exhaust back-pressure owing to the new filters is no mean feat.

The fuel-injection system now operates at 250bar rather than 200 for improved propagation, and each of the engine’s six cylinders now gets a dedicated throttle-body. The combined effect – but particularly due to the new throttle-bodies – is even sharper throttle response, says Porsche. 

Rachel Burgess and Richard Lane