utkinpol

Porsche takes serious steps to isolate their street stock cars from track related abuse, that`s all. And they stated many times already - this GT3 is NOT a car designed for a track. If you want GT3 that was built down from a cup car - there is 997.1 and 997.2.
991 GT3 was built UP from a 991 street car, not built DOWN from a cup car. it is a huge difference from engineering standpoint as it refers to completely different safety margins. long and boring talk.

It does not mean 991 gt3 will not run on a track it will only take some time for builders to find out what specifically from this chassis has to be stripped off to make it safe in track conditions. and I am not sure if it even will be worth the effort considering all the available alternatives.

and I see no big deal if those who will buy this car will do their 2-3 DE events per season on fancy 20" tires $600 apiece. after all we all need keep the economy moving.

0Q991

Making room to further differentiate the upcoming RS?

Alan Smithee

Does anybody even make a 20" slick?

utkinpol

quite obviously one will need to find a set of fitting 19" rims. open question is if existing CL 19" rims lie OZ will fit or not. if not then it will take some time for after marketers to make something up.

mark kibort

There is the answer right there!

There is no reason a slick wont work on the 991. If going up .1 Gs makes the difference from the car breaking and not breaking, its not the car for me, thats for sure! there is a fine line between slicks and DOT race rubber, some slicks are slower and dont have the grip of the BEST DOT tires. (eg A6 vs R100)
Oiling is always a concern for non drysumped engines under G loading, but wheel bearings and suspension should be a non issue for sure. (certainly the cooling system is a NON issue as well, as long as there is not air in the system

utkinpol

my most concern is still that rear axle steering mount will be torn off at the first good smack at a curb like Watkins Glen`s bus stop. People still talk that geometry is different, that it has less load, I would prefer to wait it over 2-3 years to see how it all will work out in reality.

P_collector

Why are you suprised about this? all Porsche so far mention this in the manual at one of the first pages..except the 996 997 GT series where it was "tolerated" by Porsche.

Ferrari, Lambo dont allow that either..someone told me the Mclaren would allow it..but Im not sure...

Manifold

Eek! We do need to pin down what counts as a slick, and whether the issue is just warranty or the car really can't handle the increased loads.

wanna911

Wow, I'm in shock. GT3 Neuterization complete!

I was upset and disappointed before. Now I'm disgusted. Now is there any question who Porsche is building the car for?

Hope the PDK and RWS can also make up the difference in grip level from the tires people run at the track. (fail)

Deal broken x3. (PDK,RWS,No slicks). Starting to despise Porsche for ruining one of the best cars ever under the veil of "oh, but we made it faster".



Traction wise, there is not a huge difference. I certainly wouldn't want to be guinea pig on that, crash GT3, void warranty. There is no question what Porsche will call an R6 in a warranty dispute. Anyone want to bet $150k?

I suspect the RWS program could be an issue with preset grip max levels. One has to assume the rear wheel angles have some yaw/g parameters built in. Computers don't always adjust well to big changes in grip. That's actually wishful thinking, I sure hope it's not a parts reliability issue.

P_collector

yup..on the warranty issue: just a detail how far things have gone: Porsche wouldnt extend my warranty on my 997 GT2 if I had put other tires, so if I wouldnt have put on the original Michelin CUP PILOT (which are not very good in rain, I used the argument: but its safer this way with other tires, I got refused)..now let alone changing tires at a track..this is a complete game over. But again, I dont see the real suprise here..the 991 GT3 is not a descendant from the 991 GT3 CUP..we discussed this already endlessly..

utkinpol

one thing for sure - 997.2 RS cars are not going to get cheaper any time soon. good for them, I guess.

Deetz

This:
Didn't someone mention oiling (irrespective of dry/integrated sump) being an issue??? I heard oiling from sources and (I) assumed it was the (previous) 9A1 "integrated dry sump". Now we know that even the "new dry sump" has issues and is the reason for the CUP cars continuing with Metzger...

https://rennlist.com/forums/10746249-post467.html

https://rennlist.com/forums/10677499-post22.html

Old news....

911SLOW

Bob, in which kind of technical training are you referring to?
The official publication or a Canadian Porsche /Porsche club technical session?

I can't find anything in the Porsche library.

Petevb

I'll suggest it's possible this may have nothing to do with the "factor of safety" built into the design.

Both the short tire sidewall height and playing games with the kinematics and rear wheel steering as Porsche has done with the new GT3 will make any car particularly sensitive to tires.

Actual slicks behave very differently close to the limit compared to radial street tires, and a suspension generally needs to be re-optimized to get them to work correctly. Remember that the 997 GT3 cup had different kinematics than the 997 GT3 streetcar largely for this reason, entirely different uprights, different spring rates, etc. Porsche changed nearly everything important in the suspension to get the car to work well with true slicks.

I suspect this warning may be something closer to Porsche recommending against the use of 18" wheels and tires on the 928 back in the day. It's not that the car couldn't handle the loads, it's more that the carefully tuned Weissach rear wheel steering was optimized for tires with different characteristics, and could react poorly when those characteristics changed significantly.

I generally wouldn't recommend to anyone running slicks without optimizing the suspension to work with them. This may well be Porsche's way of saying something similar, especially given the 991 GT3's likely increased sensitivity to tires.

Riz

The GT3 for the masses. It is not based on the Cup Car Metzger engine. It is a higher revving Carrera motor. The RWS has to be another factor. Race cars don't run it for a reason. Why would the Cup Car and RSR not need RWS. Don't they need more agility in tighter corners and more stability in the top speed area? This GT3 is a capable street car but a little confused. It lacks real focus like the 996 and 997 GT3's did. The RS will be more of the same imo but with slightly more hp, a little less weight, a slightly wider body, and a much bigger wing. Porsche is losing the plot. They should have called it the Carrera GTS. No wait that is the Anniversary model.