9A1 DFI Engine Improvements 991
12-26-2012, 09:54 AM
#16
The PDK Cars do not have a flywheel. That answered the question I had entertained, but it also shows how far they are going now to increase efficiency. Lower rotating mass is very important, but achieving smoothness without that customary stabilizing mass is a serious challenge.
They have met it, but it must have been the subject of some serious design studies several years ago.
Gary
They have met it, but it must have been the subject of some serious design studies several years ago.
Gary
12-26-2012, 01:39 PM
#17
Race Car
Makes me wonder whether we might see two types of induction distinguished for marketing purposes. TwinTurboBallsToTheWall (TTBTTW) turbos for the next gen Turbo model, and simple ForcedInductionButHardlyWorthMentioning (FIBHWM) for the Carreras. Oh, excuse me, that should be PTTBTTW and PFIBHWM. Ahem.
Gary
Gary
12-26-2012, 02:17 PM
#18
Nordschleife Master
Yes the PDK never had a flywheel. See photo below showing the 997.2 double pack clutches and no flywheel.
Last edited by ADias; 12-26-2012 at 06:44 PM. Reason: Photo WB corrected.
12-26-2012, 02:37 PM
#19
Race Director
12-26-2012, 02:56 PM
#20
Nordschleife Master
12-27-2012, 04:03 AM
#21
Instructor
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Under normal running the oil temp is usually about 95-105 C. So even at 60C I assume the engine is still quite cold and should be driven cautiously until full temp is reached.
Is this too cautious?
12-27-2012, 11:52 AM
#22
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Under normal running the oil temp is usually about 95-105 C. So even at 60C I assume the engine is still quite cold and should be driven cautiously until full temp is reached.
Is this too cautious?
Last edited by rodsky; 12-27-2012 at 12:51 PM.
12-27-2012, 01:32 PM
#24
Pro
I also noticed too the oil consumption of my 991 is much less than my previous 997.2. I broke in both cars in the same way, did some spirit driving and varying the engine RPM in the first 2K miles.
12-28-2012, 05:08 PM
#25
Rennlist Member
I don't know the details but recall that Porsche literature pointed out that major advances were made in thermal management on the new engine. Something about internal coolant routing and underbody shrouding. I think emissions reduction of meeting requirements is a big part of it.
12-28-2012, 06:41 PM
#27
Race Car
Porsche has definitely been talking up the thermal management, but the reality is that it is just a system that prevents the radiator from getting coolant when the car is warming up, then using that heated up coolant to warm the tranny and the cat faster. It basically speeds up the engine warm up time (which is a very good thing) but really only makes a difference in the first 10 miles of driving.
12-28-2012, 09:02 PM
#28
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Gary
12-28-2012, 09:17 PM
#29
Race Car
Just how many 991 parameters are computer controlled?
Its getting to be like my math stat prof said the first day of class, "Picture an N dimension space".
(Awaiting a post arguing about the one I just pictured).
Its getting to be like my math stat prof said the first day of class, "Picture an N dimension space".
(Awaiting a post arguing about the one I just pictured).
