Jonathan and I started work on his 2013 PW derby car. We went with a thin wedge design. Utilizing the 2.5oz tungsten canopy we milled out a pocket behind the rear axle slot and used tungsten cubes to bring it up to 4.5oz. The wheels and axles bring it up to 5oz. We taped the weight in place to take a few pics.
Nearly all of the weight is in the back of the car, should be pretty fast. We also have my daughter Abigails car for the sibling race, hers is similar except no tungsten canopy so we will mill out another pocket forward of the rear axle for more weight. I have 3 cars for the adult derby: My ducted fan car from last year I am going to tweak it a little, a modified car using extended wheel base (3 wheels touching), a 3.5oz tungsten canopy and lead weight (going to weight it around 7oz total) and a stock class car which will be like Abigail's.
The fan car is equipped with 2 five volt 3 farad capacitors. When the car is staged and the switch pushed in power is routed from the battery to the capacitors. When the pin drops power is routed from the caps to the fan. Provides max current to the fan and it automatically shuts down at the end of the track when the caps fully discharge. Car ran a best of 2.29 last year. The other car is Jonathans which was fastest in his den with a 3.00. We are working toward a good showing this year.
update on the flaming cobra car. Jonathan won 1st place for the Bear den and in the process his car generated the fastest time in the pack. Average over 3 runs (one in each lane) was 2.91 seconds on a 30ft wooden track. His fastest run was a 2.88. Pictures to follow
That's great! We ended up with an identical result. Older son won the scout class and younger son won the family class. We also have a three way race-off between the best cub scout, best sibling, and best girl scout. My boys went 1-2 in that as well. I'm a very proud dad!