I used -4 BB for this lap you should use somewhere around the same because if you dont you will kill your front tires even in a 15 minute race and loose a lot of time in the last 2 laps.

For this Track you should really get comfortable with the layout first because you have a lot of blind corners! 
generally you have to go a bit wider into the turns on this track.
In the fast chicane hit the curbs but after you hit the first one lift a bit.

Generally you should be making sure to shift just before the car hits the limiter as that gains you a lot of time in the McLaren!
Driving wise you should make sure to have a peak braking pressure of just under 100% so in the range of 90-95% and then trail of that peak pressure as soon as you start moving your wheel.
And once again as a reminder this is a fixed setup series so the only thing you can adjust is the brake bias for which i will always provide the setting i used!