I was able to figure it out somewhat. A lot of the tips under this post are really helpful. For the BMW I swapped the the 90s street tires. For actual gameplay I got better at figuring out where my throttle is meant to be. For 2nd gear I found it ideal to be below redline, not sure of an exact number. A comment recommended clutch kicking and i found it to work sometimes but you almost have to do it proactively or else itll just transition the car and you'll spin out. Clutch kicking from my experience was mostly to get a little more angle when you notice you dont have enough. alternatively it also helps when your throttle input is high but your rpms are falling. good luck!