We thought that taking 146 pounds off of a rear-engined dragster showing 75% of its weight on the rear wheels would move the fore/aft CG of the car, but that’s not the case. To keep the car performing at its championship level, we planned to move ballast weight until the percentage of weight at each wheel was equal to the measurements we had before the weight reduction. Almost no adjustment was needed because the weight reduction was at the engine bay, which is also the location of the CG.

Of course, the “vertical CG” does move lower in the car with that much reduction in engine weight. A lot of car builders strive to get their engines mounted as low as possible to lower CG, and this has the same basic effect.

Moving weight around on a long wheelbase dragster once a car is broken in and making runs can be a guessing game. The use of scales like these can eliminate the “guesstimates” that most people make in this process, and when combined with your time slips and maybe some on track video, can help to accurately document the effect of each weight change on your dragster’s performance.