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Old 08-06-2017, 04:33 PM   #297
paulca
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Quote:
Originally Posted by humfrz View Post
OK.

I challenge you (or anyone else) to do the math with the formula shown in post # 272.

If you accept, please indicate what factors you used for the variables in the formula.
humfrz
Do we even have the information we need? Exact frontal area, exact average co-efficient of drag?

My point was to get across that small increases in speed require lots of power increase. So claims of cars going 23 mph faster than the stated manufacturer number (137mph I believe, from memory) are highly unlikely.

Also that speedo readings are also highly unreliable.

GPS for that matter isn't much better. It greatly depends on the GPS used, it's accuracy and refresh rate and any equations used to smooth the usually jumpy data. Also depends on how straight and level the road is.

A proper calibrated laser or radar reading or a track day timing beam speed trap I might put more value in.
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