COM Calculations

[davet]

I'm not a pro and will probably only be racing while my boy is still a Cub Scout but maybe in the future when I retire I'll have time to dedicate to this extremely addicting "sport?".
Anyways, I was turned on to this calculator in another thread and have been entering our numbers. I'm also not a computer guy so thinking of how much work putting this calculator together was makes my head hurt. Thanks for doing this.
It seems that this could be a way to record the specs for the car and get back in the ballpark on next year's build. Have you guys found it to be accurate?

 

[davet]

This is what we're running for our Council race tomorrow on 63' track. Tuning on the kitchen table tonight after work and I think we'll set her at 4" in 4 feet for steer. Seemed to work for Districts. Do you guys see anything worth noting?

Wheelbase 5 5/8"
Rear axles 5/8" from rear
DFW left side
DFW weight: .65oz
RR wheel weight: 2.56
LR wheel weight: 1.83
Total weight: 5.04
COM Y: .725"
COM X: .024"

 

[Kinser Racing]

Drop some weight. 5.04 is to close to push it at council. You need to account for possible differences in scales.

 

[davet]

We're at 4.98 prior to tuning weight (putty).

 

[LightninBoy]

Looks good. What age group are you racing in? I've got a Lion and a Webelo 1 racing tomorrow.

 

[davet]

Bears. Have you been there before? This is our first year being competitive because of help from guys here and elsewhere. 4.98 should be safe you think?

 

[LightninBoy]

This will be my 5th time.

Regarding weight, technically you are good up to 5.045 oz (~143 grams). I've got some scales that I keep calibrated well, and run my cars up to 142.5 grams (5.03) ounces and never had any trouble with the council scales. I just make sure I've got weight in the form of putty that can be easily removed at the check in table.

 

[davet]

Your 5th time...glad we're not racing against your boy. We've got 2 identical scales and both calibrate out to 300.0 grams and both read 5.04 oz for the car. Good luck tomorrow.

 

[LightninBoy]

Your 5th time...glad we're not racing against your boy.

Be glad you are not racing in the Webelo 1s. That rank has 3 league racers that I know of.

 

[davet]

I found out that at the weigh in we're not told the weight...only told Pass or Fail and unless adjustment is VERY quick you go back to the end of the line.

 

[LightninBoy]

I found out that at the weigh in we're not told the weight...only told Pass or Fail and unless adjustment is VERY quick you go back to the end of the line.

Never seen it done that way in 5 years.