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 TC2 to be safe.
      - TC1 if you are good on the AMG
      - TC OFF if you master the AMG

HotLap/Qualifying lap adjustement:
- Front Target psi tyres at the end of the lap 26,9-27,0 
- Rear Target psi tyres at the end of the lap 26,9-27,0
- Front Toe: decrease near to -0,33 if you want more turning OR increase near to -0,25 if you want more stable (it depends on the feeling of player)
- Rear Toe: decrease near to -0,10 if you want more turning OR increase near to 0,00 if you want more stable OR don't touch 
- Front Antiroll Bar: decrease 1 click if you want more turning OR don't touch
- Rear Antiroll Bar: decrease 1 click if you want more stable OR increase 1 click if you want more turning OR don't touch
- Rear Ride Height: increase 1 click if you want more turning OR decrease 1-2 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: decrease near to -0,33 if you want more turning OR increase near to -0,25 if you want more stable (it depends on the feeling of player)
- Rear Toe: decrease near to -0,10 if you want more turning OR increase near to 0,00 if you want more stable OR don't touch 
- Front Antiroll Bar: decrease 1 click if you want more turning OR don't touch
- Rear Antiroll Bar: decrease 1 click if you want more stable OR increase 1 click if you want more turning OR don't touch
- Rear Ride Height: increase 1 click if you want more turning OR decrease 1-2 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: 2:16.010 (on a mega lap, there is the possibility of doing 15.8 mid, so you can improve so much my time)
Best lap with 80L: 2:16.905 (average time 17.2 at the stint start /on a mega lap, there is the possibility of doing 16.6 high)

Good Luck and Have Fun.

YouTube: https://www.youtube.com/@kelicful3729

TikTok: https://www.tiktok.com/@kelicful

X: https://x.com/kelicful

Instagram: https://www.instagram.com/kevin_belic/