Outlaw Derby

[TonyD]

New to the forum and looking for some help. Ran PWD cars in scouts and had a blast doing it so when a local tavern advertised an outlaw drink and derby I just had to sign up.

The Rules:
The car cannot be over 8" long, a 4X4X8" piece of fence post was provided in the kit.
The car cannot be over 3.75" wide.
BSA Wheels and axles must be used, provided in kit.
Gravity propelled only.
Car cannot weigh over 31 ounces, that is not a typo.

The Track:
The tavern owns the track which is a home made 3 lane set up, 50' in length.
The starting gate is 60" tall, cars are almost vertical when at gate.
The ramp has the profile of a circle radius, like a freestyle ski jump.

The Problem:
Since all of the normal specifications have been thrown out the window I am not sure what treatment or lube to use on my wheels and axles. I have already built the car at 31 ounces, thinking more weight is better. Its a sweet little 32 Ford 3 window, red with yellow flames, steel chassis with 5/16 steel rod used for axle housings and set screws to hold the BSA axles in the bore. Since the provided wood needed to be used it was inletted for the chassis and formed into the 32 Ford.

I just dont know what I should use for lube. Will Krytox hold up under that much weight? Or should I lookmfor something thicker due to the excessive weight?

Any advise would be greatly appriciated.

Thanks !!!!?

 

[Guest]

Welcome Tony,
Was the fence post pressure treated/images/boards/smilies/eek.gif If that car flies off the track it could bust a kneecap Tonya Harding style.
Wish my town had something like this, sounds like fun!

 

[Guest]

That sounds awesome!!!

Please send video of the race when it happens. I wanna see the cars drop in on the near vertical.

I remember post somewhere that stated that the lube was good only up to a certain weight.

Can't remember where it was. Maybe on Derby Talk. If memory serves me (and it rarely does) it was in the 16oz range.

With so few restrictions on a home made ramp, would springs or mercury help?

Best of luck,

 

[DEW36]

Welcome Tony,
Was the fence post pressure treated/images/boards/smilies/eek.gif If that car flies off the track it could bust a kneecap Tonya Harding style.
Wish my town had something like this, sounds like fun!

Now that's funny!!!

 

[Kinser Racing]

...

 

[Chief]

+1 with Kinser. I think that OPA was doing some R&D with more weight, and found that to be true? I would do like the forum guys say, and polish the bores and axles and I would use the oil and jig process. I would lighten the car body as much as possible to allow for more dense weight at the rear of your car. if at all possible I would try to do some test runs. Look at some of the pics and videos posted here on the forum that should give you some ideas.
Welcome to the forum and Best of luck. Cant wait for a video and the results...

 

[GravityX]

I would agree about the car weight. 31 oz. and plastics wheels, sounds like a disaster to me. The heavier cars may get the jump on you off the vertical drop, then friction will take over to slow them down in the flat. Hollow out that log and lighten the car down to the 6-8 oz. range, I believe this is where the point of diminishing returns takes place, per OPA's testing. Your light car will then appear to accelerate on the flat passing the other logs on the road. JM2C, more is not always better.

 

[TonyD]

Welcome Tony,
Was the fence post pressure treated/images/boards/smilies/eek.gif If that car flies off the track it could bust a kneecap Tonya Harding style.
Wish my town had something like this, sounds like fun!

Had a great laugh over this one. Sounds like I got lucky with non pressure treated. Narrowly averted a disaster.

Springs or alternative propulsion are not allowed.

Thank you guys for the info. As I was making the lead ingot for the car I was wondering if it was going to be too much. I am going to run the one I have built, but I think I will do another entry and run a lighter car. Double the fun. I will be sure to get some video of the carnage.

Thanks Guys!!!!!

 

[OPARENNEN]

Yes, I did a lot of testing for a race with similar rules.
I used a SR car from 2012 season. It had an ultra light lexan body, and 2.0 wheels, prepped as if the race was NPWDRL event. The car was 8.5 inches long. The COM was about 1.2 inches at 8 oz. It got greater as weight was added.

I started at 16 oz by using 1/16" sheet lead on the bottom of the body.

7.5 to 8.5 was the sweet spot.

In my case, every thing heavier than 8.5 oz slowed the car down
I called it the "Law of Diminishing Return"

Incidentally, I did the same test with an UNLIMITED car.
In that case, 6.0 to 7.0 oz what the sweet spot.
After multiple runs, I finally settled on 6 oz.

I sent the two cars to Olympia, WA for my son to race.
Overall they took first and second. I.e. the SR outran everybody else's open outlaw class.
The heavy UNL was 3 car lengths faster than the SR
The SR was over a car length ahead of the 3rd place car.

 

[TonyD]

Yes, I did a lot of testing for a race with similar rules.
I used a SR car from 2012 season. It had an ultra light lexan body, and 2.0 wheels, prepped as if the race was NPWDRL event. The car was 8.5 inches long. The COM was about 1.2 inches at 8 oz. It got greater as weight was added.

I started at 16 oz by using 1/16" sheet lead on the bottom of the body.

7.5 to 8.5 was the sweet spot.

In my case, every thing heavier than 8.5 oz slowed the car down
I called it the "Law of Diminishing Return"

Incidentally, I did the same test with an UNLIMITED car.
In that case, 6.0 to 7.0 oz what the sweet spot.
After multiple runs, I finally settled on 6 oz.

I sent the two cars to Olympia, WA for my son to race.
Overall they took first and second. I.e. the SR outran everybody else's open outlaw class.
The heavy UNL was 3 car lengths faster than the SR
The SR was over a car length ahead of the 3rd place car.

Thank you for the information! Since my car is already done I think I will run it as is and enter a second car. Had so much fun building the first car so why not. I will do some testing and see what I come up with for weight. That extra tall gate may make a significant difference.

We run on Feb 1st. I will take some pics and video and try to figure out how to post them.

Thank you!!!!!

 

[TonyD]

So here is what I have learned so far:

1. When making a car out of a Douglas Fir 4X4 fence post, bondo is a key component.

2. On a 50' track with a 6' gate and a 54 degree ramp, the more weight the better. Started at 31 ounces, the max, with one car and used an equal speed car and reduced to 8 ounces and up from there one ounce at a time. The 31 oz car won untill the other car had 31 ounces. BSA wheels and axles.

The race is Feb. 1st. Will update afterwords.