Soap Box Derby
 

My daughter and I are setting up a Soap Box Derby car for the city race next month.

Anyone have any advice for us?

Get the weight over the FRONT wheels.

Paul,

Why the front? I would guess that the rear would be better, if not the center for equal corner weights. Weight in the rear would be "higher" on the launch ramp and have more potential energy.

Brian

My mistake. Actually the car should be very nearly balanced front to rear. If the start ramp is great compared to the track slope, then the car should be rear heavy for the reason you mentioned. If the difference between the ramp and track is less, then the weight should be moved more foreward. If there was no start ramp, just a sloped track, then the weight should be more forward. All this is theoretical since once one end gets more loaded, then the resistance on the wheels of that end move more slowly. I would think a car w/ more front bias would be easier to steer straight, but that may be moot on these cars. In any case, for a tuopical track, apparently a very slight rear bias on a steep start ramp will give you a better start ineretia, while a car w/ a very slight front bias might actually travel down the track slightly faster. Because of this, conventional wisdom seems to be to go w/ a balanced car. There is also a limit to how much rear weight bias you can have on these things.

when I did pinewood derby with son for scouting project (same basic pricipal only a lot smaller) my car with the weight over the front wheels went a lot faster than his with weight in the middle...I think it might have something to do with it pulling the car from the start as opposed to having to push it....to put it in very simple uneducated words

Paul,

Thanks for the insight. What is your feelings / experience with 1) camber, 2) toe in, and 3) rigidity of axles relative to the car?

Also, do you know of the "proper" way to lubricate the z-glas wheels?

Thanks agian, Brian

My daughter and I did it for several years and the rules then were very strict about where you can put the weight.
They weigh the car before every race.
I have some old wheels that you are welcome to. PM your address.
You can use them to set up and test the car.
All I ask is you put a 911T registry sticker somewhere on the car. I'll send the sticker and you can send a picture of the car to me for the 911T registry site.
Here is the sticker.
http://forums.pelicanparts.com/uploa...1147658999.jpg

They're putting 911's in the soapbox derby?

Can’t wait to see the pictures.

Mike,

Thanks for the offer, most gracious. The race is the about a month away, so I've cut myself short for much testing. Also, the car we're using is sponsored by my Rotary Club, and they have expressed sensitivity to decals and such.

What I really would like to know is if there is any "magic" to "running in" the wheels I have that came with the car. They are called Z-glass. The rules seem to imply you can lubricate them prior to the race, but not during. I've spun them quite a bit by pressing the chuck of my power drill to the tread, and the bearings make a lot of noise. Graphite makes them run much quieter. Too much graphite and they slow. Is this the best I can do?

Also, the rules state that I can bend the axles to create toe-in and camber. Is this a good idea?

BTW, how did you fare in the races you ran?

Thanks,

Brian

I have heard that people bend tha axles down slightly to preload them so that the driver's weight straightens them back, resulting in zero camber. By the same logic, maybe you want slight toe in, which will return to zero as the car rolls down the track? We're talking .025" here.

have you tried a google to see what some "pros" have to say.....I am sure the web is full of information that could be used....I am also sure there are several ways to use the rules to the limit to gain the best performance....there might even be a board such as this to gain lots of useful information.

Go that way, really fast. If something gets in your way, turn.

Give me a call. My son and I run the Derby cars. We have all the go fast secrets. We're based in Hudson, just 20 minutes from Derby Downs.

Wellborn
330-592-1605

"Do you realize the street value of this mountain?"

This was 12 years ago so the rules must have changed. We had to run wheels that were supplied by the zone who was sponsoring the race. And then they were swapped every race. I guess it levels the playing field. We did okay, got a couple of trophies.
My wife and I were both in college at the time so we didn't have much extra money for travel to races but we sure had fun at the ones we did.

I volunteered downhill putting cars back on the trailer for the trip back up. If you have a bad back don't take that duty.

Have fun. Post pics.
I understand about the sticker. If you want the wheels I'll send them along anyway. Maybe you can use them next year. Actually I have all of the hardware, axles, steering etc. You are welcome to all or any of it.
i can't bring myself to put it in the trash.

"I've been going to this high school for seven years, ........I'm no dummy!"

"Everybody from the entire state of Northern California is gonna be there....."

Sorry I was no help, but Beth is my favorite name.

http://en.wikipedia.org/wiki/Better_Off_Dead

http://www.youtube.com/watch?v=_K1XGjHqyaI&search=everybody%20wants%20som e

classic