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 TC1, it's a good compromise and the grip is good on the RBR
      - TC Off if you master the M4
      - TC2 to be safe but you lose a little bit time

HotLap/Qualifying lap adjustement:
- Front Target psi tyres at the end of the lap 27,0-27,1 
- Rear Target psi tyres at the end of the lap 27,0-27,1
- Front Toe: increase 1-2 click if you want more stable but understeer appears (it depends on the feeling of player)
- Rear Toe: don't touch
- Front Antiroll Bar: decrease 1 click if you want more turning OR don't touch
- Preload diff: increase it will give you better speed in S2, but it will make it harder to pass the kerbs OR decreasing it will give you less speed in S1, but better passage over the kerbs. Advice don't exceed 150. It's up to you to find the compromise.
- 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): Adjust based on race duration. For 15 minutes, you can keep the qualifying setup. For endurance with a 1h/1h10 stint, opt for a slower setting for pure performance but consistent over the duration of the stint.
- Front Target psi tyres at the end of the lap 27,2-27,3 
- Rear Target psi tyres at the end of the lap 27,2-27,3
- Front Toe: increase 1-2 click if you want more stable but understeer appears (it depends on the feeling of player)
- Rear Toe: increase 1-2 click if you want more stable OR don't touch
- Front Antiroll Bar: decrease 1 click if you want more turning OR don't touch
- Preload diff: increase it will give you better speed in S2, but it will make it harder to pass the kerbs OR decreasing it will give you less speed in S1, but better passage over the kerbs. Advice don't exceed 150. It's up to you to find the compromise.
- 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
- Front Brake Ducts: it depends on the temperature
- Rear Brake Ducts: it depends on the temperature

My best lap with this setup: 1:26.965 (on a mega lap, there is the possibility of doing 26.8 low mid, so you can improve so much my time)

Good Luck and Have Fun.

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