I tend to lower the steering ratio because I like to have a more responsive GT3 when I turn my wheel while putting very little angle.
Don't hesitate to raise the steering ratio by 1-2 clicks if you are used to playing with more steering ratio.

TC: - I recommend the TC6 to be safe.
      - TC5 all the lap is a good possibility if you master the Mustang
      - TC4 at the exits of all haipin T1-T2, T5 for example

HotLap/Qualifying lap adjustement:
- Front Target psi tyres at the end of the lap 26,6-26,7 (peak maximum during the lap target psi 27,4-27,5)
- Rear Target psi tyres at the end of the lap 26,7-26,8 (peak maximum during the lap target psi 27,2)
- Front Toe: increase 2 clicks if you want more turning OR decrease 1 click if you want more stable but understeer appears (it depends on the feeling of player)
- Rear Toe: decrease 1-2 clicks if you want more turning OR don't touch
- Front Antiroll Bar: increase 1 click if you want more stable
- Rear Antiroll Bar: increase 1 click if you want more turning OR decrease 1 click if you want more stable
- Rear Ride Height: increase 1-2 clicks if you want more turning OR decrease 1 click if you want more stable OR don't touch

Race adjustement (advice):
- Front Target psi tyres at the end of the lap 26,6-26,7 (peak maximum during the lap target psi 27,4-27,5)
- Rear Target psi tyres at the end of the lap 26,7-26,8 (peak maximum during the lap target psi 27,2)
- Front Toe: increase 2 clicks if you want more turning OR decrease 1 click if you want more stable but understeer appears OR don't touch (it depends on the feeling of player)
- Rear Toe: decrease 1 click if you want more turning OR decrease near to 0 if you want more stable  and a better tire wear
- Front Antiroll Bar: increase 1 click if you want more stable OR don't touch
- Rear Antiroll Bar: decrease 1 click if you want more stable OR don't touch
- Rear Ride Height: decrease 1click if you want more stable OR 2 clicks but understeer appears OR don't touch
- Front Brake Ducts: it depends on the temperature
- Rear Brake Ducts: it depends on the temperature

My best lap with this setup: 8:04.272 (on a mega lap, there is the possibility of doing 03.5 mid, so you can improve so much my time)
My best lap with this setup (106L): 8:08.297 (on a mega lap, there is the possibility of doing 07.8 low, so you can improve so much my time)

Good Luck and Have Fun.

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