Need Help Finding a Starting Point

I would say try reading the burnout pattern as a starting point. That will give you the basic cold pressure, and you can adjust from there. Get some clean asfault or concrete and mildly launch the car to get the tires to spin (no burnout). Look for the darkest patches in the marks. Middle dark or narower footprint than the tire tread width is too much pressure. Dark edges and full with is not enough. If you have tubes, it will be easier to over-inflate. You also need to scale the car with you and fuel in it. Especially if it goes left and you have ladder bars.