Need help going faster!!!!

[CollinsPC]

Well now that I have you here,

My sons Boy Scout Troop is having an open class for the parents in the pinewood derby. Any suggestions? Anything is open as long as it fits the track and doesn't damage it.

They have told me already I cannot strap a rocket to mine damn it!

I was actually thinking about a solid rear axle and using a rubber band (pull back on the car to load the band and let it motor the car.)

[Martin0660]

F = M x A

Weight is your friend in a gravity race. After that, eliminate rolling resistance.

[somethingclever]

What are the rules for "open" class?

[sutyak]

Make it as heavy and aerodynamic as you can. Remember to use graphite on the "axles" before the runs.
I've won a couple pinewood derbies in my time.
Good luck!

My best car was a "wide body" car where the wheels were flush because we widened the body to the width of the wheels.
Drill holes in that sucker and fill with lead.

[CollinsPC]

F = M x A

Weight is your friend in a gravity race. After that, eliminate rolling resistance.

This isn't a gravity race per se, it is open class to do what ever we want to the car. If I could fit my R/C motor on it I would. We are going to use the gravity track but we have no restrictions. It is a fun race for the parents.

[CollinsPC]

Make it as heavy and aerodynamic as you can. Remember to use graphite on the "axles" before the runs.
I've won a couple pinewood derbies in my time.
Good luck!

My best car was a "wide body" car where the wheels were flush because we widened the body to the width of the wheels.
Drill holes in that sucker and fill with lead.

We have been to the Districts with our cars, loads of fun. This is my third go round with my sons, combined 18 cars so far .

This particular race anything goes, though I was told I was not allowed to use a rocket:D.

[CollinsPC]

Make it as heavy and aerodynamic as you can. Remember to use graphite on the "axles" before the runs.
I've won a couple pinewood derbies in my time.
Good luck!

My best car was a "wide body" car where the wheels were flush because we widened the body to the width of the wheels.
Drill holes in that sucker and fill with lead.

We have been to the Districts with our cars, loads of fun. This is my third go round with my sons, combined 18 cars so far .

This particular race anything goes, though I was told I was not allowed to use a rocket:D.

What are the rules for "open" class?

We are allowed to do anything we want, got a boosted motor I can borrow?

[somethingclever]

This particular race anything goes, though I was told I was not allowed to use a rocket:D.

If that's the case you better forget teh rubber band deal if you want to place. ;)

[jaa55]

actually gravity effects every mass with constant acceleration so weight isnt a factor except for the fact that the larger the mass the more it will resist change in velocity or have more inertia. a bowling ball and a feather will fall at the exact same velocity in a vacuum.

friction and wind resistance is your enemy

[CollinsPC]

I think CO2 is the way now!

[sutyak]

How about a C02 cartridge? Or two?
I think you might have difficulty keeping the car on the track going too fast, unless you generate your own downforce.

[phillysrt4]

there are some pinecar derby cars that have been fitted with the Estes A10-PT model rocket motor (used in boost glide rockets). They really zip! Stability might be an issue though.

as for aerodynamics, I would do a google image search for "solar car" as there is pretty much a de-facto "teardrop" shape that is proven to have a very low Cd.

[PaxtonShelby]

Retrofit the wind-up motor from an Evil Kinevel stunt bike and a line-lock...and a few chutes from paratrooper soldiers to help you slow down...

[Dan B.]

...and a few chutes from paratrooper soldiers to help you slow down...

Before it was deemed "illegal" per our derby rules, we used mercury to weight the car. Also spent a good deal of time on the axles and wheels....polished everything and made sure they ran straight to eliminate wheel "scrub".

[John4cam]

Like philly said. the tear drop is the most aerodynamic for these. I used this on mine in school and did very well. One thing to remember is make sure your axles are aligned perfectly to keep away from rolling resistance. That was where I messed up.

[jaa55]

this was my CO2 car

[CollinsPC]

this was my CO2 car

I think I am going to go with two canisters, the firing mechanism will be the hard part.

[torqueboxer]

How much dough are u trying to spend? A 1/16 scale brushless motor/controller/lipo battery setup would rock their world!!

When i worked for my dad we sold the parts for the derby cars...so funny...all the bettis nuclear/ westinghouse engineers would be building there cars for the kids and running fluid dynamics/aerodynamic analysis programs on the cars. The best was one year a little kid with his single mom built one by just cutting a 45deg angle on the square block and pounding the wheels on with a meat tenderizer!! They went round after round with that car he won a trophy over all the "pro" built cars.

[CollinsPC]

How much dough are u trying to spend? A 1/16 scale brushless motor/controller/lipo battery setup would rock their world!!

When i worked for my dad we sold the parts for the derby cars...so funny...all the bettis nuclear/ westinghouse engineers would be building there cars for the kids and running fluid dynamics/aerodynamic analysis programs on the cars. The best was one year a little kid with his single mom built one by just cutting a 45deg angle on the square block and pounding the wheels on with a meat tenderizer!! They went round after round with that car he won a trophy over all the "pro" built cars.

I thought about trying to fit the motor off my RC car lol. How much we talking for the brushless motor?