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#1
03-09-2012, 07:45 PM
 EVKid Junior Member Join Date: Jul 2009 Location: Dallas Posts: 2
Power Needed formula. What is Area in m^2 referring to?

Power in Watts = ((Mass in kg) (9.8m/sē) (Velocity in m/s) (Rolling Resistance)) + ((0.6465) (Coefficient of Drag) (Area in mē) (Velocity^3))

I'm just getting started here... can someone help me?

I'm using 0.2 for the Coefficient of Drag, 0.014 for the Rolling Resistance, but I'm not sure what Area in m^2 is referring to...

Mike
-I might have blown the motor on my old corolla and my boss denied my trip to Asia, if the block is cracked, I'm considering of using my new found resources for a conversion...
#2
03-22-2012, 09:11 PM
 madderscience Senior Member Join Date: Jun 2008 Location: Seattle, WA, USA Posts: 708
Re: Power Needed formula. What is Area in m^2 referring to?

area (m^2) refers to the frontal surface area of the car. The first approximation of this is the smallest enclosing rectangle defined by the maximum width of the body, and the maximum height of the car, minus ground clearance.

And I believe it is velocity squared, not cubed.

0.2 is a pretty low coefficient of drag. Hope you found an accurate source source. 0.014 is a pretty safe Rolling Resistance ratio. The right tires and an alignment job and other small tweaks can get it to 0.01 without too much effort.
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1985 Toyota MR2 EV conversion
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#3
03-22-2012, 10:29 PM
 frodus Senior Member Join Date: Apr 2008 Location: Portland, OR Posts: 3,155

m^2 is square meters. Width times height of the vehicle
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Travis Gintz
Electro Motive Force, LLC.
EV Consulting and parts Sales
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#4
03-23-2012, 07:08 AM
 EVKid Junior Member Join Date: Jul 2009 Location: Dallas Posts: 2
Re: Power Needed formula. What is Area in m^2 referring to?

Thanks guys, I was thinking no one was ever going to answer to this...

Mikey

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