Aerodynamic & Rolling Resistance, Horse Power & MPG Calculator

[mikeyjd]

I did 2 calculations for reference:

Stock Festiva

My Festiva

Aspire


Note: At 31mph 50% of Festiva Horse Power goes into overcoming aerodynamic resistance.

[Spike]

That's pretty cool. So I assume the 'HP' line is how much horsepower is required to move at a certain speed? 64HP at 115MPH sounds about right, that's top end, and some have gotten a carb (past where they likely should) to about 120.

Awesome.

-Joe

EDIT: Darn it, I was looking at your Festiva, not stock. Eh, dumb me. Still pretty awesome.

[mikeyjd]

[FestYboy]

mikey, that math is off quite a bit... if 50% of the power from the B3 is used at 31 mph, then that would put our top speed at 62 mph....

power vs speed is logrythmic, not linear. with air speed, it's every doubling of speed requires 4x the power to get there.

[TominMO]

I notice that the Stock Festy calculated results are off--at least in my experience. At 45 MPH I got 62.5 MPG; at 55 MPH I got 58.0 MPG; at 60 MPH I got 52.5 MPG.

[mikeyjd]

mikey, that math is off quite a bit... if 50% of the power from the B3 is used at 31 mph, then that would put our top speed at 62 mph....

power vs speed is logrythmic, not linear. with air speed, it's every doubling of speed requires 4x the power to get there.

*50% of the horse power being used is to overcome drag, it takes about 3hp to maintain 31mph with Stock Festiva. To go 62mph it takes a little over 12hp or roughly 4x as much.

I notice that the Stock Festy calculated results are off--at least in my experience. At 45 MPH I got 62.5 MPG; at 55 MPH I got 58.0 MPG; at 60 MPH I got 52.5 MPG.

These numbers won't equate to experience per say. They are just a peak at different variables in 100% controlled conditions on a flat surface.

[sketchman]

DO EEET!

With something lighter than clay.