The new Porsche 911 GT3 that's due to be launched at the Geneva motor show in March will have a 4.0-litre flat six engine, according to a well-informed source close to the factory. It will not be the same 4.0-litre engine that's found in the current GT3 RS and 911 R, but an evolution capable of producing "at least" the same 500bhp and up from the 475bhp of the last ‘standard’ GT3.
The main focus of the development work has been to improve further the durability of the engine, resulting in a motor that "has done thousands of kilometres, absolutely flat out, with no problems at all".
As already speculated, the 991-generation GT3 will be available for the first time with a choice of a six-speed manual gearbox or a seven-speed PDK dual-clutch automatic transmission. A plan to stiffen the suspension and make a much more hardcore product has apparently been dropped in favour of a more user-friendly set-up, in line with traditional GT3 thinking.
Meanwhile, work continues apace on the forthcoming GT2 RS, which "should be ready by the end of the year", our source said.
Initially Porsche engineers were looking for a massive power gain, even compared with the 612bhp of the original 2010 GT2 RS, but a plan to realise 700bhp was sidelined when it became clear the engine would need a water injection system to keep internal temperatures under control.
Instead, engineers are believed to have settled on an output of around 650bhp, almost 90bhp more than the engine produces in the current 911 Turbo S. That would provide for a specific output of more than 170bhp per litre.
Another source confirmed that this would be the last outing for the engine, which is based on previous-generation technology, and that the next Turbo would be based on the new flat sixes seen in the current Porsche 911 Carrera, S and GTS, but with an enlarged capacity.
After the GT2 RS, the next GT model will be a Cayman GT4 RS, complete with a 4.0-litre engine. So fast is the current four-cylinder Cayman S that Porsche officials privately concede that, if shod with an equivalent tyre, it would be as quick around the Nürburgring as the existing Cayman GT4, so a big performance leap is expected.
Clearly it won’t have the full 500bhp-plus provided to the new GT3, but expect an output of at least 430bhp, a clear 50bhp rise over the Cayman GT4 and more than enough to establish a clear performance margin to lesser, non-GT Cayman models.