ok...I just rationalized/derived this formula and it gave me a reasonal number, but if isn't right someone can correct me <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt='
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SPEED=[(RPM)/(GR*FD)]*0.00595*TR
where
GR=gear ratio
FD=final drive ratio
TR=tire radius in inches
RPM=duh!
This gives 159.1mph at 6900RPM, .759 5th gear, 4.08 final, and 12" TR (24" tire)
Find your TR with xxx/yy/zz being the tire size:
TR={[(2*0.yy*xxx)/24.5]+zz}/2