PDA

View Full Version : Drag Racing

08-28-2010, 08:51 PM
Whats a good distance for drag racing? 330ft = 1/16th mile or 660 ft = 1/8th mile.

NovaSavage
08-28-2010, 10:13 PM
132 ft is 1/10 scale 1/4 mile.

09-01-2010, 01:02 PM
Is that for scale MPH?

BrianG
09-01-2010, 02:48 PM
Scale MPH doesn't linearly correspond to the vehicle scale. So, if your 10th scale vehicle is doing 60mph, it's not doing 600mph scale speed, but 189.74mph.

When you ask what a "good" drag racing length is, what do you mean? Do you mean the proper length to get to top speed or what?

streetdemon
09-01-2010, 02:53 PM
Scale MPH doesn't linearly correspond to the vehicle scale. So, if your 10th scale vehicle is doing 60mph, it's not doing 600mph scale speed, but 189.74mph.

When you ask what a "good" drag racing length is, what do you mean? Do you mean the proper length to get to top speed or what?
By any chance do you have the formula for scale speed? Thanks.

BrianG
09-01-2010, 03:00 PM
It's SQRT(scale) * actual_speed. So, for a 10th scale model clocked at 60mph, the scale speed is: SQRT(10)*60, or 189.74mph.

09-01-2010, 06:26 PM
My track is 330ft long which is 1/16 mile, to figure Avg. MPH should the math be Avg MPH= 330/time ?

streetdemon
09-03-2010, 03:53 PM
Yes and no. The BASE equation is distance over time for average speed. The equation figures in exactly what it says, miles over hours or M/H=avg speed.

Since you are using feet and seconds, you need to add some conversions.
For the distance, you are going to use 1/16 instead of 330. so now you are at [1/16(miles)]/hours
For the time, you need another conversion, so instead of hours you are using seconds. There are 3600 seconds in an hour. So for this you are going to plug in 3600/T for your time.
Now we have [1/16(miles)]/[3600/T] = avg mph. T being your time from start to finish.