The nearest we have seen to the 991 GT3 is the GT3 Cup but that is powered by the old Hans Metzger designed 3.8 litre flat six, not the brand new 3.8 litre flat 6 which is going in the road going GT3.
The unnamed Rennlister happened upon the GT3 in a garage and on track in an unnamed location. He spoke with the engineers working on the car and took some photos and recorded a soundclip.
Here's what he said about the car:
Information after discussion with the test driver and engineers and watching/touching the actual car
It sounds incredible. Exactly like a cup car.
Completely different PDK
Engine is a bespoke motorsports block, and the basis for the next gen Cup engine. Dry sump.
Yes, it's not the DFI 9A1 and it's not the Mezger. It's a new engine!
- RPM to 10K, redline 9 dead, 3.8L engine. Power is north of 450hp but they wouldn't say exactly.
- No PDCC, no PTV *at least not in this car
- New rear wing, very similar to 997.2 wing, but up close it's more refined
- Air scoop is beautiful, center feeding
- Car is running Dunlop Sport MAXX, 245/20 front 305/20 rear
- Car retains traditional 3 piece muffler, identical side mufflers as before but looks like a new, smaller center.
- New brake system, front caliper is ENORMOUS, disc is alternating drilled size.
- New recaro seats, foldable (not one piece), car was a Clubsport version fitted with the rear cage
- Nurburgring times are right around 7.30
- Center locks
- ESC (electronic stability control), TC, sport exhaust, PDK-S (on the center console)
- Wide body chassis from C4
- rear control arms look like the ones in the 997 GT cars