My son did his science project on pinewood derby cars this year. We raced 27 different cars testing things like weight, length, COG, shape, etc. Then we ran a few cars combining everything that we learned. We didn't learn anything new that would help us build a faster car. I think the interesting takeaway was the degree of importance of certain things. Here are a few things that surprised me:
We raced a block and tested the COG at several different places. I knew ahead of time that as we moved the COG back, the car would run faster. It didn't. It actually ran slower each time we moved the COG back. We built a thin wedge with an extended wheel base that had been tuned and got the expected result. So, when the kid comes asking for help that has a car that looks like a tank or hotdog, I wouldn't automatically assume that putting the weight in the back will help.
Obviously, weight is important, but not as important as I thought. I was surprised that a ladder car that had been properly tuned with absolutely no weight (total weight of the car was 0.8 oz) still smoked a 5 oz block.
Shape. As expected, the thin wedge destroys every other shape. We tried keeping everything equal such as COG, etc.) and tested blocks, tear drops, etc. I think most people on here knew this already, but the thin wedge always wins. I assumed this was the case b/c it's hard to put the weight in the back with a tear drop shaped car, but even with the same COG, the tear drop lost by a lot to the wedge.
Special thanks to TurboDerby for letting us use his track and helping us build some rockets.
We raced a block and tested the COG at several different places. I knew ahead of time that as we moved the COG back, the car would run faster. It didn't. It actually ran slower each time we moved the COG back. We built a thin wedge with an extended wheel base that had been tuned and got the expected result. So, when the kid comes asking for help that has a car that looks like a tank or hotdog, I wouldn't automatically assume that putting the weight in the back will help.
Obviously, weight is important, but not as important as I thought. I was surprised that a ladder car that had been properly tuned with absolutely no weight (total weight of the car was 0.8 oz) still smoked a 5 oz block.
Shape. As expected, the thin wedge destroys every other shape. We tried keeping everything equal such as COG, etc.) and tested blocks, tear drops, etc. I think most people on here knew this already, but the thin wedge always wins. I assumed this was the case b/c it's hard to put the weight in the back with a tear drop shaped car, but even with the same COG, the tear drop lost by a lot to the wedge.
Special thanks to TurboDerby for letting us use his track and helping us build some rockets.
