There are many opinions on how to run a Grand Prix Race, this is mine. I’m not saying that there is anything wrong with the other ways, I’ll just tell you why I do it the Wright way. 🙂
First of all I want you to know I don’t do elimination racing, it’s not the most fare way to run a race, and it’s not any fun for the child with the slower car who is out after just a few races. Everyone races the same amount and against as many different people as possible, the same number of times in each lane, except if you run finals rounds. I use a great software package to manage this, and it makes running the races easy and enjoyable. 
Grand Prix Race Manager (GPRM) takes the stress out of race day by setting all your heats for you and keeping track of all the results. Also there are many reports available to print or e-mail to the people that want to know every detail of the race.
I recommend an electronic finish line unit with computer interface ($60 and up), and Grand Prix Race Manager software, (link on the right), I judged a race without the electronics once and that was enough. After that day my research began, and I found GPRM. Since I am involved with Awana I have a four lane track, Red, Blue, Green and Yellow lanes. The GPRM software allows you to customize it to lane colours or lane numbers which ever you prefer, and will handle 1-8 lanes, and a wide selection of finish line detectors available on the market today. I prefer a wooden track, after all it is also called the pinewood derby by BSA, but aluminum will do. Plans for a wooden track are available for download on this site, it will cost around $200-$300 to build compared to $800-$1000 for a good aluminum track the same size. Also there are pointers for electronic finish line units on the site.
Start planning well in advance of the date you pick for your race, make sure you have enough time to build or buy your track, or schedule someone to come and help you run a race with their track. Keep in mind if you are asking someone else to come, their schedule may not line up with yours easily. Also consider the time and travel expenses of the person coming to help you. They have invested in their equipment and there is some upkeep and occasional upgrades needed to continue using it.
Once you have your track and all the peripherals arranged, and the date set, it is time to order your car kits and start promoting the Race. Allow at least a month for building the cars, I prefer six weeks if possible, because kids procrastinate more than I do and need to be reminded a few times to get the lead out. 😉 Don’t forget the trophies, Awana has them available and don’t forget the category plates for the trophies. You may need a little more time if dealing with a trophy shop.
Remember some children will need help, not everybody does woodworking at home or has a parent that even knows how to shape a block of wood into a car. Arrange to have one or more pit days to help these families, or at least have someone available with a saw to rough cut the design out of the block for them. This is what I do now, as I have run pit days and had nobody show up, I bring my saw with me to club three or four weeks in a row and will cut out the cars for anyone who brings it to me. I have also made time for parents to bring their childs block to my house to have it cut out. I have some simple Car Design templates available for kids that can’t make up their minds. I have cut these out of plexiglass and hardboard (like peg board without the holes). I had a large sheet with a white finish to it left over from another project and I try to add a couple different shapes each year.
Also think about a Leader/Parent category this will stop the parents from taking over the project as they can work on their own car, besides we like to have fun too. If you want some entertainment to get you in the mood, look into “Down and Derby”, a comedy about dad’s taking over their son’s first pinewood derby. It was sponsored by and filmed in cooperation with BSA and has some great well known actors in it. You can always race the adults in the middle of your race in their own group or mix them in using master scheduling and separate them out for the standings. There are lots of software options so please refer to the software website or contact me for more details.
Make sure to allow enough time for all the aspects of your race. Meaning enough time to test run the cars to make sure they all cross the finish line, judge the cars for design, and run all the heats required in your race (determined by number of entries and how many runs in each lane). The software can help you with this, I like to have all the entries entered ahead of time so I can play around with the best number of runs to get the length of time I want. I can run a heat every 30-40 seconds on average so I plan on 60 seconds per heat, this allows for unexpected delays due to restroom breaks or car repairs. A quick way to figure this out for two runs per lane for a total of eight races per entry will usually take twice as many heats as entries. Example: 30 entries, 2 runs per lane on a 4 lane track equals 60 heats, or 60 minutes of racing. Also you may have to very the number of runs depending on the number of entries, it doesn’t always work out just how you want, sometimes you just have to run an odd number of runs per lane to make it work, or try allowing a bye, this is an easy way to get the number of runs you want without changing how much time you have planned for your race time.
If you happen to have an accident free race and need to fill time you can always start a new round or finals round with a few of the top racers as a run off for the trophies, or allow a few challenge races, such as adults against children.