Grant. I dont disagree but the stock 3.8 991S puts out exactly the same torque on paper to the 991 GT3 (324lbft). My thoughts are there must be something they left on the table for the 991 GT3RS. AP has already openly stated in two interviews that the engine makes more than its quotes 475 PS so with some additional ECU mapping a tweaked inlet manifold and exhaust and a slight re-profiling of the cam Im suggesting they will find a little more PS (maybe only 15-20 in reality but of the 991 GT3 engine is understated perhaps they have some wiggle room) and another 12+ lbft torque (I agree this will be much harder to find). Back in the 964 days we were all told the 3.6 would be hard to get more power and torque out of but they managed that twice with the 993 non varioram and then the varioram version effectively lifting HP over 5 years from 250 to 282 and torque by around 18lbft peak. It may be that the 991 GT3RS has very similar peak torque (i.e. say 330lbft) but that its up to 15lbft fatter in critical parts of the curve. Im guessing they will use a cam to move the peak torque and PS as they still have some headroom between 8250 and 9000 rpm. I dont believe the will lift the max rpm.

My other theory is they will do nothing at all with the engine and gearbox like they did with the 997.1 GT3 and what we will see is some small weight reduction, some better handling through suspension and tyres. This is quite possible but probably less than 50% likely (although Porsche suprises alot these days).

I think we will 100% see PDK-S only and 4WS. Im also 99% sure we will not see a displacement increase in this generation. To keep the headline max rpm limit at 9000 will require some additional strengthening and internal lightening word with a 4.0L engine IMO...