Length of track for heavy wheels to win, or for 4 on the floor to win

[txchemist]

This problem changes dramatically with the level of performance of the car. First let's look at 4 vs. 3 wheels. Case one- car is typical poor build, 2.6 gr. wheels, not so thin, not so aero. The 4 wheeler basically does not catch up until the 3 wheeler almost stops. So running a junk car, the 4 wheeler can catch up at 146 ft.

If we run the test again with two really good NPWDR cars, the 3 wheeler runs a lot farther before it conks out and gets passed by the 4 wheeler. That distance is 521 ft.

Now the second case has a NPWDR 3 wheeler racing against an equally well built car but the back wheels have 3 cubes stuck in them so the wheels weight 16.5 gr. each. That car can catch the 3 wheeler at the 426.5 ft. mark.

Not too many tracks long enough to mess with it.

 

[Guest]

That is amazing!

One day I am gonna bug you to teach me that trick.

I have a feeling it might take more than one lesson though.

The tortoise and the hair eh?

Astounding!

 

[kickaxe]

Wow......so my earlier post on a separate topic was way off in terms of the distance ...........

"To echo those before me, as long as the track is not obnoxiously long (somewhere around

55-60 feet), then lighter wheels are always faster."

Lighter wheels and 3 touching vs. 4 makes a much bigger difference.

Is there a wheel weight (ignoring the fragile nature of plastic) that wheels can become too light or is lighter always better?

 

[txchemist]

The unlimited and the eliminator wheels are close to the mechanical limit, and the moment of inertia along with the weight is super low. Some day, might have a carbon nano tube-graphine wheel, but it will cost you plenty.

 

[CliffordT]

Last fall I raced on a 350' wooden track under the assumption that after the initial fall the rest of the track would be flat. I packed my wheels with tungsten putty (the only means I had to evenly weight the wheels on short notice), trying to generate momentum to carry for the flat. This also let me find a good place to pack on mass for the 8 oz limit and still keeps a very thin profile. End result? I got crushed, the track ended up being on a continuous hill that had essentially no flat. The track was ridiculously rough (lots of 8' plywood sections with terribly mismatched transitions) but the final winner had a very traditionally made car. Lesson learned, get your car in the best position to accelerate on the hill and forget about heavy wheels!