From Boy Scout experience, I drank water (and pee'd) all day! If you aren't peeing at least once an hour, you aren't taking in enough fluids.
I know, a little too much information.
I don't know that I went quite that often but yes, lots of bathrooms breaks 
It was an incredible time on Saturday. Glad that we all got to participate. The thing that struck me the most was how much easier the GT-R's are to drive than the Z's.
Almost effortless at times! And anytime I felt like I was about to get into trouble, the GT-R was just like, "Don't worry, son. I got you. Go ahead. Give it a bit more throttle. It'll all be ok." 
I don't think I got over 120 mph in a Z, but easily hit 165 mph in GT-R on the back stretch, and it was effortless.
Yeah about 125 mph in both my Z and the stock Nismo Z, IIRC. I was with a slower guest group in the GT-R so I don't think we even hit 160, but to be honest, I wasn't even paying attention the speed it was just so much fun to drive lol
My biggest problem was that I had never driven a manual Z before; mine is a 7-AT. It wasn't that I couldn't drive it, but I had to think about my gear changes; they weren't natural to me. That was a bit distracting.
This is exactly how I felt driving Matt's 7AT in the morning session. I tried paddle-shifting, and it was just so unfamiliar that I was completely befuddled. I was only able to keep speed because we were going so slow, and my lines were so bad it was embarrassing. In fact, at one point I hit the windshield wipers and they got stuck under his GoPro on the front window 
Once I got back in my 6MT in the afternoon (and the Nismo Z), it was all good 
There's just something about a clutch pedal. Not to mention grabbing a stick with a knob 
The GT-R in automatic mode was awesome, though. I didn't even both to try paddles in the afternoon session. It kept high RPMs without upshifting even with light throttle application, and it downshifted at high RPMs leaving you perfect for maximum acceleration on exit.
I was fine in my car until the oil temp got too hot to paddle shift - I was right above 255. I could definitely feel a bit of a loss in performance as it got hotter. In full auto mode, it just doesn't shift quickly enough. Matt has a 7-AT, but also has an oil cooler so he had no problem.
I am wondering how much my tune allowed me to continue pushing the car even after 250 oil temps. I was about 260 after the first three hard laps. She cooled down to 220 before we went out again, but was back at 260 after the 2nd lap. What was surprising was that it jumped up another 30 degrees in the next half lap. I was pushing it to take the second position after a rotation when I hit 290 and said ok no more acceleration, and luckily immediately after that straight away the instructor in the lead car announced the the rest of the lap would be cool down for the cars. I had the radio in hand ready to let him know that I was going to have to drop to the back to cool her off and would be pitting next chance when he came on said cool down time 
The instructor came up to me after one of the sessions in my car and asked why I started falling back. That's when I told him about the overheating/paddle shift issue. After that, I just stayed in a Nismo 370 and then the GT-R and had no problem staying up with him when it was my turn.
Nice The stock oil coolers are perfect for this type of application -a few laps at a time with lots of cooling off time in between. I think with any kind of sustained track use, those stock Zs would be right where you were temp-wise
Again, what and amazing day.