To use your scales, first you have to run your car on the oval track and get a baseline setup. Tune all day by changing tires, springs, oil, geometry, tweak, etc ... Once you've found a good fast, controllable setup, then put the car on the scales and note the tire weights.
This will be your starting point for the track next time you're there.
We have an article on our site about using scales on oval:
www.swiftracingproducts.com
Go to the Technical section, then Team Tips ...