wow finally! Got 1st lap in 1.30,
2nd was a low-1.27 (drafted a car on the straight),
3rd was mid-1.27,
4th was a mid-1.27 and
5th lap was a high-1.28 (due to spin-out finish move)
I figured out using the walls as brakes is not so bad! But it will mess up your paint job...
Here were the settings on the 2007 GTR (491 HP, 1411 kg):
Downforce = Max (22)
Trans. = 168 MPH
Acid = 7/6, 19/22, 20/20
Split = 10/90%
Suspension = -20/-13, 12.6/ 15.3, 6/6, 5/5, 4/4
Alignment = 3.9/1.0, 0.07/0.19
Brakes = 10/7
What helped was learning the rhythm on the last loop-turn before the straight, as well as how to angle your car to hit the wall after the straight for maximum speed.
If you aim for the portion of the loop with the orange/black stripe barriers going about 120 MPH it will drop you down to the proper speed of about 85 MPH and then you just gun it out of there (it's almost like a 90 degree turn). That turned out to be faster than anything else I could do.
Also, on the short loop about half way through, slow way down and do like a V-shape path on that guy. I slowed down to about 25-35 MPH through there.