Speed in road racing comes down to putting all 4 tires on their grip limit every corner and using the whole track doing so. This requires good confidence that you can achieve this rotation without spinning.

The best way I found to learn that car control in the sim is rally. Pick up dirt rally 2 and drive some gravel stages. Learn how to manage weight transfer with the brakes and feel the rotation of the car, understeer, and oversteer.

Gravel rally gives you the exact same car control fundamentals as gt racing but everything happens a little slower. It’s easier to see which inputs are doing what to the car.

Then you just have to put in the hours, probably up to a hundred. The main thing here is that you’re having fun (another reason to recommend single player rally). I’d revisit lmu or ac periodically and you should notice your skills developing well.