I got gold here on my 4th or 5th lap. I got somewhere in the 1:16.7 or 1:16.8 range. I think a low 1:16, if not a 1:16 flat is attainable. After doing the GT5P M3 event with professional physics and no driver aids (except abs:1), I didn't think this was nearly as hard.
Others have put some good tips out there, but I'll write up my lap. Driver aids - ABS:1, everything else off.
T1 - brake hard, stay in relatively close, and apex super late. You want to be most of the way track-right when exiting. If you track out to the left, you ruined it - next time through brake more and turn later.
T1 to T2 - when exiting T1, you will NOT be able to get full on the gas. The car is simply too unsettled (if you are carrying any sort of speed). Just use a little gas to keep the back end settled, and take a tight entry into T2. The proper racing line would be to stay wide and turn in later, but this can be taken almost like a double apex to cut off distance. Since you can't carry much more speed anyway, and the tight entry doesn't kill your exit speed, it's ok to head right for the first apex.
T2 - after you enter tight to the left, do not let the car drive out mid-corner more than a car-width from the inside. Keep the speeds low and gently rotate the car until you can just about eye the track-out point to the right. The "second" apex needs to be late, and you need to ease into the throttle down the hill. Floor it too quickly and you will fishtail (slower).
T3 - Similar concept to T1, but more banking and a wider turn. Make sure not to cheat on turn-in, and use all the track available to the left (there is a kink in the track, so you can't use literally ALL the track). Again apex super late, and if you track out left, you will ruin one of the longer straights on the track.
T4/T5 - Enter this turn about midway, and be SUPER smooth. Minimal sliding through here is fastest. If you slide, you will have to wait until the car is settled before getting on the gas. It's downhill, but the banking will help. Make sure to hit both the inside apex on the left, and then again on the right.
T6 - Others have said to slide through here, but I don't think that's fastest. The key here is to start far left, and gently work the car in to a very late apex. If you truly apex late enough, you should be able to get all the power down by the exit. If you hit the wall, you apexed too early. If you are fishtailing, you weren't smooth enough on the power and/or didn't apex late enough.
Tunnel - be very smooth through the tunnel, it can be easy to upset the car.
T8 (turn after tunnel) - easy on the brake here, you don't need to slow down too much. Again, make sure not to track out too much to the left. You need to stay track-right or mid track so you can stay on the power through T9.
Last turn - now you head through a strange, uphill braking zone and a sweeping double-apex turn that swings back down to the right with start/finish around the bend to the left. Brake hard and in a straight line. You will want to tweak the braking point here - the key is to clip the first apex on the right as you are braking, and continue past this apex (not too far off the track) to line up for the downhill right hand apex. This 2nd apex is more important. If you did it right (tracked out far enough, turned in late enough) you should be able to accelerate through this point and be flat on the throttle around the last slight left bend into start/finish.
There are really 2 themes with this event - easy on the power and late apexes. You really need to think 2, maybe 3 corners ahead. It's one thing to take T1 as fast as possible, but then you will ruin T2 and the short downhill straight. As far as right foot smoothness on the power, my first lap was probably a 1:19x - I didn't change much with the line between the attempts (just minor tweaks), the biggest difference was minimizing spinning the tires coming out of corners.
I hope this helps...good luck.
