New to the Derby

General discussions for car and semi-truck racers.
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BearDad59
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New to the Derby

Post by BearDad59 »

Hello All,

So I have a first time Scout in a Bear den and we had our PWD this past weekend. I spent alot of time on YouTube and way too much time on the car and we took first place overall at our derby!

The competition is stiff and we now have the bullseye on our backs. I was part of the set up and did not find out until after that our car was .01 oz light. My question is how much could that have improved our time?

We ran on an aluminum 42 ft track. Our best time was 3.414 seconds.

Thanks.

BD59
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Re: New to the Derby

Post by Eagle »

Likely speed left on the table would come from someplace other than the .01oz under. Add the .01 an on the next scale you might have to take it off.
If you want to run it again check out http://www.TheWestCoastGrandPrix.com
Speedster
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Re: New to the Derby

Post by Speedster »

Welcome to Derbytalk, BearDad59

.01 ounce is 0.28 grams as near as I can figure. A fraction of a gram has no affect on speed per Dr. John Jobe, Author of the Big Green Book, the Physics of the Pinewood Derby with Engineering Applications. 1 gram less will cost 1/8" at the finish line.

I (ASSUME) you raced on a "Best" track since you knew it was a 42' track. If Best track punched the holes then the cars traveled 36'10" from start pin to timer.
Since your Team is racing scouts I'll guess only graphite was allowed and not oil.
Here are some times recorded on 2019 Scout races, Bear Class, Graphite only, 2019 Mid America Race, 42' Best Track.
1st Place - 2.933
12th Place - 3.071
Yes, the rules are probably different from yours but it's something to keep in mind if your Team decides to take part in the Mid America race this year around the 1st of May. Your Team's car is probably legal as it is. You can mail the car to them. You can also race in Eagle's race and mail the car to him.

Does your Team race again in another race?

"and way too much time on the car". I didn't know that was possible. How much time did your scout spend on the car?
Best Wishes to your Scout and you.
Speedster
BearDad59
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Re: New to the Derby

Post by BearDad59 »

Speedster wrote: Tue Jan 28, 2020 9:18 am Welcome to Derbytalk, BearDad59

.01 ounce is 0.28 grams as near as I can figure. A fraction of a gram has no affect on speed per Dr. John Jobe, Author of the Big Green Book, the Physics of the Pinewood Derby with Engineering Applications. 1 gram less will cost 1/8" at the finish line.

I (ASSUME) you raced on a "Best" track since you knew it was a 42' track. If Best track punched the holes then the cars traveled 36'10" from start pin to timer.
Since your Team is racing scouts I'll guess only graphite was allowed and not oil.
Here are some times recorded on 2019 Scout races, Bear Class, Graphite only, 2019 Mid America Race, 42' Best Track.
1st Place - 2.933
12th Place - 3.071
Yes, the rules are probably different from yours but it's something to keep in mind if your Team decides to take part in the Mid America race this year around the 1st of May. Your Team's car is probably legal as it is. You can mail the car to them. You can also race in Eagle's race and mail the car to him.

Does your Team race again in another race?

"and way too much time on the car". I didn't know that was possible. How much time did your scout spend on the car?
Best Wishes to your Scout and you.
Speedster
Maybe I'm staying things wrong. We weighed in at 4.9 oz. How much did I slow us down by not hitting the 5 oz mark?

You're right to assume it was graphite only. We do have the option to go to districts if we can swing it time wise. That's yet to be determined.

By those times we look pretty slow!

We spent about a week in the evenings after school and before bed and some of that Saturday. I'd say 12-14 hours. My son didn't use the scroll saw but did sand, paint and help with axle prep, measurements and weights. As for $ I bought things we could use for the next two years since we had literally nothing. I have a jig for axle holes, a mandrel, and some weight. I borrowed a block to bend axles but I may buy that next year. Maybe $50 bucks on Amazon...most of that on the 3.5 oz tungsten dome weight.
Speedster
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Re: New to the Derby

Post by Speedster »

4.9 ounces equals 138.95 grams. 5 ounces is 141.75 grams. The difference is 2.78 grams. Roughly you're a tiny bit over 1/4". The timers are recording times to .001 of a second. If you are running down a 4 lane Best track, your time is being recorded for elapsed time, your worst time is removed and the rest is added, you might be in trouble. I raced a car on a 4 lane Best track , once in each lane. Worst run was removed. I was beat by .004 of a second. This was a very close friend of mine. Nothing to do with Scouts. The point of all this is have the car weigh 141.75 grams.

You're a GREAT Dad.

Might we see a picture of the car?
BearDad59
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Re: New to the Derby

Post by BearDad59 »

I don't have a picture hosting site set but I'll try.
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davet
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Re: New to the Derby

Post by davet »

Great first showing for your team.
I would say by your time that a majority of your speed was lost elsewhere.
A lighter car can beat a heavier car if the lighter car was weighted, prepped and steer correctly and the heavier car was not.
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davet
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Re: New to the Derby

Post by davet »

When my boy was in Scouts we would use the Pa k race to get an initial setup.
We steered it and weighted and prepped wheels and axles correctly.
But, we got more aggressive with rear weight bias for Districts then more so for Council.
Without a track to practice on use the Pack race to get a good baseline. Make sure the wobble is out.
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