Is that the calculated bhp or the actual figure on the wheel that the dyno showed? If the latter then it is whp not bhp.
The usual conversion factor for an approximation of bhp from whp is 0.85. 72.93 whp /0.85 = 85.8 bhp.
However, the factor is different for every drive train so 0.85 may be way off for a M3W. The only real way to get bhp is to measure it at the crankshaft.
~iw
