LOLS996TT

Great video- thanks for sharing! It is pretty wild how tracks and their soil "breathe" throughout time. The track looks like it is a ton of fun to drive and running down the GT3RS was very fun to watch lol! I will be at COTA for the first time next month, however it will be for the Moto GP weekend. I think the track layout is very neat and very much looking forward to seeing it in person! Great runs and thanks again for sharing!

powdrhound

I've got some track time in a 991GT3. The PDK boxes are simply amazing. Same car, manual v. PDK, the PDK car will be faster. The millisecond shift of the PDK allow you to bang through the gears significantly faster that any human could and it also allows you to bang through the gear in the hight speed sweepers without upsetting the balance of the car. For a track car, I would always go with a PDK for max performance. There are downsides to PDK of course but they are not performance related.

powdrhound

Yeah, the bump in 18 is substantial. I can't imagine they would be able to run F1 with it like that. I'm sure it will be fixed. I was still trying to figure out how to best approach the carousel to mitigate the bump. I basically tried to get most of my turn done prior to it so I could hit the dip without having the car loaded with max Gs at that point.

sinking

I was there the Saturday you were there, but not running my car. I saw your car and stopped a moment to admire as I was walking past all the garages. I know I had read you were going to be there, but wish I made the connection when I saw your car so I could chat about it some.

powdrhound

You should have come by and said hello. I didn't run Saturday, loaded up after lunch and was on the road by 2pm.

996tnz

Thanks for posting your vid John.If the straight was one and a half times as long you'd likely have got him. I'm sure you'll have come to the same conclusions, but on checking my in-car vids : for a long time it LOOKS like we are not gaining on a lower powered car, because they are further along the track and have been accelerating slower, but also for longer than us so our speeds are fairly close for a while. And in terms of distance, for some time from corner exit, we really aren't gaining on them. But maintaining that same distance as both cars accelerate means we are gaining on them in terms of time, which is what really matters anyway. On my regular track, the longest straight comes off a hairpin, and I always get the momentary feeling that say a 250HP car is holding me off during the exit as we don't gain ground for a while. But when we do start gaining its pretty much an exponential function that sees us slingshot by them going 20+ mph faster as we near the braking zone.

Tires make a big difference don't they. Haven't had to face a GT4 or GT4CS on a regular track yet, but they look to be a handful if well shod. Only just managed to hold one off (driven by our 2014 national Porsche circuit series winner) to take a recent Porsche Club autocross, and that same guy was also fast (I suspect a bit quicker than we were) when they pulled in the cones and opened the tight and twisty club circuit up to full laps afterwards.

You looked to be pushing hard, with nice use of the kerbs. He was probably just running his own lines but it almost looked like the Cayman deliberately ran a late apex line through some corners to throw you off (eg 7:35 - nice save). Could see your lines through some of the esses get quicker over those laps so I'm sure your times would keep falling as you worked the track out further. I love your telemetry overlay - both informative and tidy. Am I right in seeing you left-foot brake to adjust and maintain the cars attitude mid-corner?

Thanks again for putting this up and I feel privileged looking over your shoulder. The high-speed point-bys were interesting too as we don't use them here. I noticed several guys only point when the passing car was already alongside so I guess it's just a 'best effort' system.

powdrhound

Good observations ^^^. The extra power that my car has really does not give as much of an advantage as many would think because you can really only use the power in the straights. The rest of the track like the esses and the long sweepers can only be taken at partial power so this is where a light car and slicks will have a huge advantage that you have to try to make up on the straights and into the braking zones. A high grip light car will naturally have the advantage of higher corner exit speeds also. I was starting to experiment with different lines in the various corners in order to look at data at the end of the day to see what works better with my set up. Motec makes this very easy as it splits the track up into individual segments where you can look at your segment times along with all the other data. Unfortunately I didn't get a change to run the next day to clean things up.

As far as the GT4 and the GT4CS, totally different animals. Basically same as comparing a 997GT3 and a 997Cup with it's light weight, slicks, and a sequential gearbox.

I could generally take an earlier apex than the 4CS because I have the advantage of greater torque on corner exit. Thus it appears that I'm pinching him off in several corners, specifically at 7:35 and 9:15 where I had to trail brake super late as I got a little close to him. This made the back end to step out a bit. Again, I was still experimenting to see what worked better.

Yes, PCA in the US has a hard on for point bys. Many places are pretty flexible but at COTA you can't get away with any thing due to all the cameras present. They were pretty strict. I generally didn't fully accelerate until I was sure I was getting a point by. The track was schedule to go to unrestricted passing on Saturday, Friday was restricted.

etchhead

Great video and sweet driving! I was also trying to figure out what that Cayman was. Having just moved away from Radical with good power/slicks/down force you really have to drive differently in a heavy TT shod with NTs.

COTA also on my bucket list and when I get there I'll be referring back to your vids- thanks for sharing.