Getting off the line

[Sylvar]

What are the main factors effecting how fast a car gets out of the starting gate?

Shane

[WarpSpeedINC]

Wheel weight and braking torque due to axle/wheelbore finish, wheel diameter and lubrication.
Our take anyway!

Warp Speed

[Sylvar]

Ok. Racing with standard rules that say you can't modify the wheels what can we do?

Wheel Weight: Not much can be done here

Wheel Diameter: Again not much can be done..Which is better, bigger or smaller?

axle/wheelbore finish: I feel like my son does a great job of polishing the axles..Wheel bores scare me though. We use the MaxV Wheel shaver and with the bore polisher. I am not sure that the bore polisher is getting out all the marks that the wheel shaver leaves behind.

lubrication: I think he does a good job here too, but he could probably be more diligent

He did very well last year. He was beat off the line a lot, He always pulled it out in the flat. His design was more speed oriented last year....This year he wants to build a more creative car (It will look like a grasshopper). He isn't gunning for the speed trophies this year, but wants to at least be competitive.

Thanks for the input!

Shane

[Stan Pope]

What Warp said is how it should be.

In some cases, slow starting gate operation will give an advantage to "barge" (elevated) nose designs. Slow operation comes from manually opened gates that are operated against tension that kept the gate closed while 15 or 20 ounces of "hot cars" tried to push it open.

[joe]

The fastest starting car I've seen had the wheels rounded (mostly illegal!) and very smooth. Makes a case I think for sanding your wheels FLAT (legal!) with very fine paper -- My guess was that the weight of the wheels was a bit less, and that the rolling resistance was lower, thus a faster start.

[ranman106]

With standard rules:

Good wheel/axle prep and a barge front!

[ExtremePWD]

I believe that graphite can cause some binding and a slower start. We lubricate with Hob-E-lube which is fairly coarse right out of the tube. You can feel the extra drag until the wheels are spun in. Even after run in, I have anecdotal evidence that if the car sits awhile, probably with some vibration or disturbance, the graphite can reorient and bind for the next run.

[pinecarpro]

Wheel Diameter: Again not much can be done..Which is better, bigger or smaller?

I find smaller to be better

Pinecar

[Stan Pope]

I find smaller to be better

This is consistent with theory ... small loss in increased braking torque vs proportionately large reduction in rotational inertia because of the preponderance of rim mass.