Looking for advice on my first car

[Motorlust]

Hello everyone,

First off, love the forum here... I have gotten a peek into the depths of pinewood derby racing. I am a fan of speed and I am already feeling the bug of this soon to be obsession.

My reason for the post however is that we are having a pinewood derby as a work event, and I have full intentions of winning. We have a lot of events at work, and I have succeeded in winning most of them at least once (chili cook-off, Olympics, egg drop, pumpkin carving, beard growing, costume contest, paper plane contest... Etc). I now have my sites on winning the pinewood derby and need the help of pros like you guys.

There is prize $ and sweet custom made trophy.. I will post some photos when I win them..

The rules we were given are here: https://docs.google.com/a/atlanticb...gO90YAP4ADipBmCq_2xnNByWa6o/edit?usp=drivesdk

Based on the rules and a budget of maybe $40 or so what would be my best bet?

It looks like the most popular cars are the wedge design and the minimal looking body designs with the canopy weights. Any recommendations on body type? Also wheels and Axel's, what's the best bang for my buck?

I have read some and watched videos of builders testing car alignment on a treadmill.. know I am prepaired to do all of this if I know it will help me... Haha

Should I buy a kit that has most of what I need, look for a finished/used car or start from scratch?

Any help you guys could provide would be huge, so thanks in advanced.

Corey aka motorlust!

 

[jatofau1]

Motorist, I could not access the rules. You might want to post the rules on the forum so we can help you.

 

[Motorlust]

Motorist, I could not access the rules. You might want to post the rules on the forum so we can help you.

Sorry, only people at work had access. I made a new link... https://docs.google.com/document/d/163FX-muu5ohUVprdEmnCk5y5uuMXc11cKCi3OlvYw0Y/edit?usp=drivesdk

 

[Rocket car]

A 10 ounce unlimited car will do it !!
Plan on spending $150-$250 on parts though.

 

[Ballistic Racing]

Those rules are pretty generic, & the $40 budget is gonna be the real killer. You're gonna spend close to $40 just for your weight.

 

[Jimmy & his 2 Kids]

I'm still stuck on the 10 oz weight limit!
Make sure to post what you end up doing Motorlust. The gurus here will set you straight. That limit tho changes things for sure.

 

[bracketracer]

I don't see where the rules outlaw bearings, I would increase your budget and run them, especially at 10 oz. You'll have to ream the bores to fit the bearings since they ruled out drilling though. lol

Thin to win applies even to heavy cars.

 

[BulldogRacing]

Ask around here for some bearings and and razors that did not make the cut for us and you may get some discounted parts that will make your fellow workers heads spin.

 

[derbydude]

It says wheels in the kit must be used

 

[bracketracer]

It says wheels in the kit must be used

True, but it doesn't say that the car has to ROLL on the kit wheels. Use them as decoration on top, sunk into the body and roll the car on bearing razors. You used the wheels, you met the rules as written. It's probably not what they intended, but it's what they wrote!

 

[TWarwick07]

Wow 10 ounce car, was that intentional or a typo when they wrote the rules

 

[robo4881]

Don't use a treadmill

 

[Motorlust]

It says wheels in the kit must be used

I did ask about this... They also said you could buy your own kit and use those wheels... So I don't think the wheels will be reviewed much as long as they look like kit wheels.

 

[Jimmy & his 2 Kids]

Wow 10 ounce car, was that intentional or a typo when they wrote the rules

I had wondered the same thing.

 

[robo4881]

I had wondered the same thing.

We had an adult race at our council race. The max weight was 10 oz also. I won with the car I built, it was around 9.7 oz. I believe 5 kids racing did a study for one of his kids projects at school or something like that. They ran a car and kept adding weight. I can't remember how high They went but it had gains when they added the extra weight.

 

[5KidsRacing]

Here is a copy of what I wrote on the PWDR site a few years ago...

My oldest Son decided to do his 6th grade science fair project on the effects on weight vs. speed with a pinewood derby car. Last night we built and ran the car and I would like to share the results. The car was a railrider and had a set of wheels I had cut for my Pure Stock car and had 91 axles. The car was prepped with Legend and Jig-A-Loo and ran oil. The car ran very well and very straight. The car weighed almost exactly 2 ounces with no weight, but we had to start with some weight in the rear otherwise the car would tip onto the guide pin. I have a bunch of ½ ounce brass pins so we started with 2 pins so the car weighed 3 ounces and we ran the car 5 times and recorded the results. We added 2 more pins each time and repeated the experiment up to 10 ounces. Since the car kept going faster we ran a few more tests at 11, 12, 13 & 14 ounces to see what happened.

Here is the car:

Here are the results:

3 ounces:
3.125
3.126
3.118
3.120
3.120

4 ounces:
3.068
3.069
3.067
3.064
3.067

5 ounces:
3.028
3.028
3.029
3.031
3.031

6 ounces:
3.008
3.007
3.007
3.008
3.008

7 ounces:
2.993
2.992
2.993
2.993
2.991

8 ounces:
2.981
2.982
2.981
2.981
2.981

9 ounces:
2.972
2.973
2.973
2.973
2.971

10 ounces:
2.967
2.968
2.968
2.967
2.967

11 ounces:
2.964
2.962
2.963

12 ounces:
2.962
2.960
2.960

13 ounces:
2.958
2.959
2.958

14 ounces:
2.956
2.953
2.952

I had read on another board a couple years ago that after about 9 ounces any additional weight wouldn’t add to the cars speed. I don’t believe that now. Maybe with graphite there is a maximum effective weight, but with oil it seems you can go much heavier and still gain speed.

 

[bracketracer]

I notice that the gain per ounce really starts to diminish by 10-11 ounces.

 

[Jimmy & his 2 Kids]

Nice experiment 5Kids! Thanks for sharing. What type, length track? Which I forget if you mentioned that or not in the bio's on your site. I find it interesting that the amount of gain from oz to oz isn't as much as I thought it would be... with properly prepped BASX & Box Stock cars running similar times as that car with 1, 2, 3 ozs & more I figured there would be bigger gains. Faster sure, just not as fast as I thought it would be.

 

[5KidsRacing]

42 Ft. Best Track!

 

[DerbyDad4Hire]

Use lead for weight. You will need firm wheels. I could put something together for you in your budget to build with.