I was at Barber for the same event, driving my old trustworthy 996 GT3. I can tell you that the composure of the new car through the corners was even more impressive than what comes across in that video. The temps that weekend were brutal – near 100F air temps in the afternoon and well above 90F even during the AM sessions. I had decent grip only in the very first session each of the two days, and laps 3-5 or so of every other session: 2 laps to warm up, maybe 3 decent laps and then progressively worsening greasiness and loss of grip thereafter. The rear end on my car felt as if I was driving on ice. My car had Yokohama street tires (AD08R), which are usually fairly decent, but felt worse than I’ve ever experienced before, which I attribute to the extremely hot conditions. I measured almost 190F on my rear treads – 15 min after parking the car! A good friend of mine had older Hoosier R6’s on his car, and also experienced significant loss of grip midway into each session. By comparison, the white 991 GT3 on MPSC-2’s looked as if it was on rails. On a cool day with the car fully broken in, I imagine this thing could put down some truly impressive lap times.

 

Where the turbo gets out of shape is the classic unweighted crest where you need to be under power and straight ahead ... just a light throttle a bit of steering input and the car will rotate like that ... prodigious stability control intervention pulls it neatly into shape without encouraging the driver into overcorrection ... not exactly poetry in motion, but impressive technology. I imagine the turbo was roasting all four tires and probably up to 50psi in the rears if not corrected from normal pressures.
Even driven mildly, the 991 GT3 overwhelms the sport cups -- this driver was perhaps managing the tires and generally driving very clean and smooth (though PDK makes "smooth" easier than in a manual gearbox car.)

 

I don't understand your final statement about the 991gt3 overwhelming it's tyres. I agree the MPSC2 are the single thing holding the car back but I found from my laps that the chassis really works to help you find the ultimate slip angles for those tyres before in anyway abiding them so keeping an optimal contact patch and retaining grip with little squealing or obvious greasiness even when the tyres are well above ideal temps. I was very impressed but I come from my 993RS track hack which is quite different to get a fast lap in....

 

I dunno ... I wouldn't expect others to treat my early remarks too seriously based on one day self-limiting to 6000 rpm and 50% throttle. But I imagine you know when a car feels like it needs more stick -- not more camber or spring, just more stick in the tires and more aero if it do it.

I'll need a couple of sessions, maybe a couple of days logging temps and pressures to see if the MPSC2 can be made to handle the car, but between weight and raw power and brakes, the 991 GT3 feels a bit like the 997.2 GT3 RS 3.8 ... completely under-shoed on the Sport Cups, and capable of leaning the Hoosier R6 till they're shredded.

One immediately apparent difference between the "new" GT3 and the "old" RS is how composed and unflustered the GT3 can be while working the limits of traction. The RS can take you there (and maybe further, maybe at higher speeds) it really lets you know you're working. The "warning" of the GT3 is that it will continue to rotate, lose speed and lose traction, front or rear or both, but the RS, the "warning" is more of an epitaph ... you know for sure what went wrong ... and next time, you just have to pick up your skills and reflexes ... or pay for the repairs ... : ) It's quite surprising how much the GT3 can get out of the tires before the traction and stability electronics intervene ... even when they do, it's subtle and costs little in terms of pace or line. The caution flag I'd raise there is that the tires just can't keep the car on the track ... brakes are more than tires, engine is more than tires and the chassis is more than the tires ... by a lot. Just as I type, perhaps a useful analogy is driving in the wet. This is a car that can be driven like it's on rails, but once you have the tires at 32 hot and you're confident it's sticky, but not greasy, it feels like an RS feels when driving Hoosiers on a damp track ... predictable, not at all treacherous (other than whatever lurks on the surface and contours of the track itself) but you can tell all your work is now handling the tires and the car is well within its envelope.
That's not to suggest it's not fun -- it's laugh in your helmet fun -- and I was packing up yesterday wishing I had another day or at least a few more sessions once I got settled in the car. It's a car that's easy to learn and be familiar -- literally three or five laps and you find yourself right in the feel of the car and starting to pick up its subtleties (despite the lead weights Porsche has used in the steering ...) The challenges for the next step will be the brakes (modulation is rubbery) and maybe letting a little more roll into the rear sway to give up the fun of four wheel drifts (nothing to do with "drifting") and encourage more throttle steer with smoother inputs.

Or so it seems to me. : )

 

carreraGT. Its always good to have new owners feedback and you probably have a much more sensitive "bum" than me! I have not taken the 991 GT3 to "the edge" on the track yet (that will come in a few weeks time when we have our annual track tour) so I have not identified that the car is "under shoed" although I concur the rear tyres seem narrow relative to the outgoing 4.0/3.8RS but the fronts have increased in width and I was thinking the factory kept the 305 rear due to the newly introduced benefits of RWS and aero countering the need for more rear tyre patch.

There is no doubt the MPSC2 is the weak link although IMO its a better tyre than what has been shod on the GT3 as stock up until now. I am used to Hankook Z214/221 a hoosier grip level tyre on the 993 which IMO is another step or two ahead in terms of stickiness again (I use C70 soft compound).

That being said I havent yet over driven the GT3 on road or track. Ive tried on a few occasions only to run out of road or *****! From what Im hearing from those who have much more track time in the car than me a geo is essential and adjustment of the sway bars. I have changed my geo to be a little more aggressive (-2.15F/-1.95R) and did notice better turn in and I imagine tyre heat management (fronts). I need more track sessions with ESC/TC off and better hot tyre temps (29/32 seems to be the agreed sweet spot hot) before I can make claims with any authority.

Im very interested to learn what esq8est has experienced with the R6 on the 19s last weekend but need to find the thread to see if he has updated.

Anyway, its good to get your feedback...

 

I have a very sensitive bum, but I can't word it like CGT.
Can't wait for the track report!!