General Hints:
Watch the hotlaps of the fast guys. See where they use more track, brake later/differently and get on the power earlier. Watch their splits and compare them to yours.
You need to be in the low 31s for the first sector if you want to go sub 1:35. A low 1:06 or high 1:05 at the second split should see a sub 1:35 time for the lap if you get the last couple of turns right.
Look at your tyre temps. Is the outside edge of the front right tyre about optimum for the tyre type - 60 degrees I think for this car? With the inside edge a few degrees hotter? That's what you need for this circuit.
Only apply power when you are sure you will not need to lift again.
Keep the car tidy - whenever it is sliding (back or front) you are losing forward momentum.
Don't lock the brakes, your braking distances will increase.
Brake at the 75m board for the first corner. Brake at the 100m board for the 'Carlube Corner' at the end of the long back straight.
You need to maintain 46mph through turn 1 and you should be hard on the power from the exit of the corner all the way through turns 2 and 3. You need to turn in early for turn 2 but ensure you don't take too much kerb. This will almost certainly end up with the car on its back waving its legs in the air
You want to maintain 64 - 65 mph for turn 4, increasing to 67-68mph for turn 5 and be accelerating early on exit all the way through the slight left curve of turn 6. For turn 7 brake as the kerbs start, use full width and maintain 63 - 64mph. The final chicane must be negatiated no slower than 67mph. Beware, your right hand tyres will probably be cold.