how would you calculate scale speed??

Multiply by the actual speed by the inverse of the scale.

10 mph / 1/10 = scale speed

10 mph / 1/10
10 mph * 10
100 scale mph

thanks

So my 45 mph Cen fun factor is doing 450 mph scale?!?!?

Yup.

hmmm hang on.....

dont constants such as gravity and friction coefficents kinda screw the real calculations up some what?

no maybe not, maybe thats just takin things too far eh?

Friction and gravity still apply in related terms regardless of the scale with equal drag and weight distributed relatively... basically neither can be counted as a factor of bias towards one scale or another

The only factor that might be considered biased is the road the cars are running on. the pebbles, potholes, and debris you run through remain a constant shape and size, and being that larger wheels mean a better contact patch, you might say that the road favors 1:1 over 1:10. Not in all cases, but most... just my 0.02

Yes it does. For example, model airplanes have much thicker wings than their full-size counterparts because air molecules remain the same size. As kurosen pointed out, the road (and it’s problems) remains the same size.) Finally, air resistance is a cube function, so it takes a tremendous amount of extra power to go faster than to go slower.

All that being the case, however, the scale still applies. But remember, 1/12 on-road cars go 60 mph in actual races. That’s why the concept of scale speed is so abstract that it doesn’t have any useful meaning.

I have a friend that races boats and he's always reminding me that while we can adjust the surface we run on to fit the scale of our toy cars, there is no way to scale waves on water. I think the same applies to things like air resistance, inertia, and surface friction so it's really a bit more complicated than it sounds. When you consider the fact that it takes a very specialized 1:1 car to run 450 mph in a straight line then watch a 10th scale sedan running a sweeper at 40 or so actual mph like it's just another day on the track, it's easy to understand the huge differences between sale models and the real thing. It sure is cool to be able to simply slap an extra zero on the right hand side of your actual speed though. The simple fact that we have toys that off the shelf will run in excess of 50 actual mph is still nothing short of amazing when you compare that to what was happening just 4 years ago, and would have been laughed at as impossible ten years ago.

just mark out a scale mile and give ur car a long runup so its goin g fill throttle from start to finish of the scale mile and see how long it takes to go the scale mile. then just work it out.