Quote:
Originally Posted by paulca
For what it's worth, I plugged in some numbers. The equation is not that scary. However it's a bit basic and does include anything for rolling resistance etc. which while small would shave a few percent off.
power=147000 (fly wheel watts)
aird=1.3
area=2.28 (sq m)
cod=0.27
x = (2*power) / (aird * cod * area )
v = e(l(x)/3) (this is a cube root)
v * 2.23694 (m/s to mph)
160.20993999770118933534
The frontal area is a guess from the total width and total height on the spec.
147,000 watts = 197 bhp.
When we modify that to "wheel hp" from a bit of googling we get:
power=117000 (157 wheel hp)
x = (2*power) / (aird * cod * area )
v = e(l(x)/3)
v * 2.23694
148.47236739928096565100
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Hi ya, paulca
Your figuring appears to be accurate ........
However, the values I used are a bit different.
I used:
160 WHP (averaging several values reported on the internet)
density = 1.3
Cd = .27
frontal area = 21.2 sq. ft. (figure published by Car & Driver)
Plugging those numbers into the formula, my abacus gives me a calculated top speed of a stock 2013 FR-S, of roughly ......
157 MPH.
(I think your estimated frontal area of 2.28 m squared is a bit high)
Your thoughts ......??
humfrz