Porsche appears set to roll out with an updated version of its 911 RSR, which is believed to center around a switch to a turbocharged powerplant, in time for the 2019-20 FIA World Endurance Championship season.

Leading German motorsports publication Auto Motor und Sport has revealed a series of spy photos of the new generation GTE contender, which was caught testing in a pre-production phase in Weissach.

While featuring visible changes to the side cooling vents, the photos also show external exhaust tubes, indicating early experimentation of a potentially new exhaust layout.

According to those that have heard it in person, including the photographer, the car sounds like a “vacuum cleaner” and not like the current high-pitched scream of its 24 Hours of Le Mans GTE-Pro class-winning 911 RSR.

The German manufacturer has yet to acknowledge or confirm existence of the car, although Head of Motorsport Dr. Frank-Steffen Walliser has previously hinted of another new project in the works for 2019.

Porsche has already announced plans for new GT3 and GT4-spec machinery that will be rolled out next year, with a GT2-spec car, based on the 911 GT2 RS, also likely at some stage.

It’s understood the new-gen GTE car could be revealed at Porsche’s Rennsport Reunion at WeatherTech Raceway Laguna Seca later this month.

Whether it would be considered an all-new car or rather an Evo kit, however, remains unclear, although an engine change would likely require a new homologation.

Should the switch be made, it would result in an all-turbo GTE field by 2020, once Corvette’s new mid-engined C8.R debuts.

Under current rules, new cars would only be able to debut at the start of the new GTE regulations cycle, which is slated to begin with the 2019-20 WEC season-opener at Silverstone in September.

IMSA will adopt the next three-year cycle beginning with the 2020 Rolex 24 at Daytona.

Head of Porsche Motorsport Dr. Frank-Steffen Walliser has discounted rumors of the German manufacturer switching to a turbocharged engine for its next-generation Porsche 911 RSR, stating that he doesn’t see a big need to go away from its tried-and-trusted normally aspirated powerplant.

Spy shots of what appears to be Porsche’s new-for-2019 GTE car were revealed last month, with a car featuring a revised exhaust configuration.

Eyewitness reports of a significantly different sounding engine, likely due to the muffled noise from the externally-placed exhaust tubes, led to speculation that a switch could be in the works for its next car, likely due in time for the start of the 2019-20 FIA World Endurance Championship season.

While Walliser declined to comment on the spy shots or the existence of a new GTE car altogether, he did admit that he still sees no performance difference by going with a turbo under the current regulations.

“For me it’s properly balanced,” he told Sportscar365. “But this is not depending on turbo or no turbo. The turbos are controlled, they look at the temperatures of the intercoolers, they look at the boost pressures and all these things. For me it’s fine.”

When asked if he sees a long-term future of continuing with normally aspirated flat-six engines in its 911 GTE race cars, Walliser said it depends on the link to Porsche’s production cars.

“For sure, I look at the street cars,” he said. “If I asked the guys here [at Rennsport], ‘Should we stay normally aspirated or do you want a turbo?’ It’s only normally aspirated. If I go down in the paddock and ask, there’s craziness about normally aspirated engines.

“So this is very essential: the link to the street cars. The guys understand more to change the position of the engine than turbo or normally aspirated.

“Performance-wise, it doesn’t make a difference. It’s a different concept but it’s balanceable. I don’t feel a big need. It’s something we can do but we’re not pushing for it.”

With the GTE class set to begin a new three-year regulations cycle in mid-2019, following the WEC ‘Super Season’-ending 24 Hours of Le Mans, Walliser acknowledged it does present an opportunity for manufacturers to roll out a new homologation, or simply opt for an Evo kit to its existing car.

“You have a new homologation period and it’s up to you if you go for an update of the car or keep the [existing] car,” Walliser said.

“Some competitors have done it the hard way [with] Evos. Knowing what you have is also good. But a new homologation is a new homologation.”

Sportscar365 believes that the new-gen 911 RSR could be revealed before the end of this year.