Find Out Your Car's Race Weight
Published: August 2, 2013
Are you curious to know what your car weighs as it is driving on a race track? Depending on what organizations you run with, this might be easier than you think.
Most competition classes in NASA either have a minimum weight requirement or they require a certain power to weight ratio. In both cases, cars must be weighed to determine their actual weight during competition. As a result, nearly all if not all competitive events should have scales present.
If you run with NASA, you can have your car weighed for free in "race trim", i.e., without any of the items that you take out for track sessions, with you in the car, and with however much fuel you want to have in the car. Walk up to the tech area and inquire whether the scales are available and when you can use them.
Usually the time to weigh your car is when the scales are set up but race cars are not using them, which in turn is around lunch. Since race groups typically run a qualifying and then a race, scales are set up for qualifying and packed after the last race group finishes their race. You want to use them between qualifying and race sessions, or between race sessions provided they are sufficiently spaced out.
Tip: look up and write down your car's wheelbase before going to the scale. This will save you time and make the tech people happy.
Besides your total weight you can also obtain corner weights for your car, that is, how much of the weight is resting over each of the tires. The surface under the scales is not guaranteed to be flat and level, which does not matter for the total weight but matters more for corner weights. Take corner weights as approximate unless you can find out for sure that the scale area is level.
Organizations other than NASA have different rules and may or may not have scales available. Organizations that do not combine race and HPDE events in one day are unlikely to have scales for HPDE events, even if their race classes are based on weights. Regardless of who you run with you can always ask whether scales are available.