the absolute most performance that can potentially be squeezed out of 911 platform is if they use two electric turbos on the flat six and two electric motors on the front axle … so about 800 hp on the rear and 200 on the front and 1,000 hp total … this at about 500 lbs lighter than Plaid …
however Porsche aren’t a bunch of tuners who are trying to get the most performance possible - they are a serious company that thinks big-picture, that is they think about where the car fits in VolksWagen group line-up, how it stacks up against competition from AMG etc. and also what is the path forward - how could it be upgraded for the NEXT iteration of the model … ( or maybe they will decide this is the last 911 )
so really you have to ask - what is the natural competition for the 911 ? i do not think it is Plaid. it is probably AMG GT:
remember AMG GT uses 4.0 liter Turbo and top 911 Turbo engines are 3.8 liter which is pretty much the same. yes AMG GT is 8 cylinder and 911 is 6 but it is not cylinder count or even displacement that matters but rather PISTON SURFACE AREA, which is roughly equal for the AMG V8 and Porsche Flat 6 ( actually Porsche 6 has slightly larger Piston Area than AMG 8 )
AMG was first with electric turbo technology initially in Formula 1, then in C63 E-Performance, but now Porsche has it too. And of course between Panamera Hybrid and Taycan Porsche has similar tech to what AMG uses in their PHEVs to supplement gas power with electric power.
the Turbo S will probably do enough to stay competitive with AMG GT, and not more. with wider tires and benefit of AWD the 911 might not need to match AMG GT for horsepower in order to beat it on performance, so maybe they will do like 700 hp.
will it have a plug ? hard to say. the reason European cars have plugs is they get to write off taxes on the plugs in Europe. the AMG PHEVs at about 6KWH battery are really in between a regular hybrid like 911 GTS ( which has 1.6 KHW ) and a real PHEV like Panamera ( which has 25 KHW battery ). so the AMG isn’t going for fuel economy as much as just tax write offs, that said if you live in a high rise you would be better off with a regular hybrid than PHEV because a regular hybrid may use slightly different battery chemistry that can sacrifice range for other qualities you can actually benefit from.